Inadequate sleep as a risk factor for obesity: analyses of the NHANES I
STUDY OBJECTIVES: Sleep deprivation has been hypothesized to contribute toward obesity by decreasing leptin, increasing ghrelin, and compromising insulin sensitivity. This study examines cross-sectional and longitudinal data from a large United States sample to determine whether sleep duration is associated with obesity and weight gain. DESIGN: Longitudinal analyses of the 1982-1984, 1987, and 1992 NHANES I Followup Studies and cross-sectional analysis of the 1982-1984 study. SETTING: Probability sample of the civilian noninstitutionalized population of the United States. PARTICIPANTS: Sample sizes of 9,588 for the cross-sectional analyses, 8,073 for the 1987, and 6,981 for the 1992 longitudinal analyses. MEASUREMENTS AND RESULTS: Measured weight in 1982-1984 and self-reported weights in 1987 and 1992. Subjects between the ages of 32 and 49 years with self-reported sleep durations at baseline less than 7 hours had higher average body mass indexes and were more likely to be obese than subjects with sleep durations of 7 hours. Sleep durations over 7 hours were not consistently associated with either an increased or decreased likelihood of obesity in the cross-sectional and longitudinal results. Each additional hour of sleep at baseline was negatively associated with change in body mass index over the follow-up period, but this association was small and statistically insignificant. CONCLUSIONS: These findings support the hypothesis that sleep duration is associated with obesity in a large longitudinally monitored United States sample. These observations support earlier experimental sleep studies and provide a basis for future studies on weight control interventions that increase the quantity and quality of sleep
The incidence of deep and lobar intracerebral hemorrhage in whites, blacks, and Hispanics - Reply
Incidence of intracerebral hemorrhage and predictors of deep versus lobar location in a multi-ethnic population: The Northern Manhattan Stroke Study
Sleep duration associated with mortality in elderly, but not middle-aged, adults in a large US sample
STUDY OBJECTIVES: To explore age differences in the relationship between sleep duration and mortality by conducting analyses stratified by age. Both short and long sleep durations have been found to be associated with mortality. Short sleep duration is associated with negative health outcomes, but there is little evidence that long sleep duration has adverse health effects. No epidemiologic studies have published multivariate analyses stratified by age, even though life expectancy is 75 years and the majority of deaths occur in the elderly. DESIGN: Multivariate longitudinal analyses of the first National Health and Nutrition Examination Survey using Cox proportional hazards models. SETTING: Probability sample (n = 9789) of the civilian noninstitutionalized population of the United States between 1982 and 1992. PARTICIPANTS: Subjects aged 32 to 86 years. MEASUREMENTS AND RESULTS: In multivariate analyses controlling for many covariates, no relationship was found in middle-aged subjects between short sleep of 5 hours or less and mortality (hazards ratio [HR] = 0.67, 95% confidence interval [CI] 0.43-1.05) or long sleep of 9 hours or more and mortality (HR = 1.04, 95% CI 0.66-1.65). A U-shaped relationship was found only in elderly subjects, with both short sleep duration (HR = 1.27, 95% CI 1.06-1.53) and long sleep duration (HR = 1.36, 95% CI 1.15-1.60) having significantly higher HRs. CONCLUSIONS: The relationship between sleep duration and mortality is largely influenced by deaths in elderly subjects and by the measurement of sleep durations closely before death. Long sleep duration is unlikely to contribute toward mortality but, rather, is a consequence of medical conditions and age-related sleep changes
Sleep duration as a risk factor for diabetes incidence in a large U.S. sample
STUDY OBJECTIVES: To explore the relationship between sleep duration and diabetes incidence over an 8- to 10-year follow-up period in data from the First National Health and Nutrition Examination Survey (NHANES I). We hypothesized that prolonged short sleep duration is associated with diabetes and that obesity and hypertension act as partial mediators of this relationship. The increased load on the pancreas from insulin resistance induced by chronically short sleep durations can, over time, compromise beta-cell function and lead to type 2 diabetes. No plausible mechanism has been identified by which long sleep duration could lead to diabetes. DESIGN: Multivariate longitudinal analyses of the NHANES I using logistic regression models. SETTING: Probability sample (n=8992) of the noninstitutionalized population of the United States between 1982 and 1992. PARTICIPANTS: Subjects between the ages of 32 and 86 years. MEASUREMENTS AND RESULTS: Between 1982 and 1992, 4.8% of the sample (n=430) were determined by physician diagnosis, hospital record, or cause of death to be incident cases of diabetes. Subjects with sleep durations of 5 or fewer hours (odds ratio = 1.47, 95% confidence interval 1.03-2.09) and subjects with sleep durations of 9 or more hours (odds ratio = 1.52, 95% confidence interval 1.06-2.18) were significantly more likely to have incident diabetes over the follow-up period after controlling for covariates. CONCLUSIONS: Short sleep duration could be a significant risk factor for diabetes. The association between long sleep duration and diabetes incidence is more likely to be due to some unmeasured confounder such as poor sleep quality
Predictors of risk and protection for hypertension in Yup'ik people from Southwest Alaska
OBJECTIVE: Hypertension (HTN) contributes to vascular disease, and is increasingly common in non-western, rural contexts, such as the Yup'ik people of Southwestern Alaska. While much is known regarding HTN risk factors in western contexts, little is known about their relevance to non-western populations. We explore an American Heart Association risk factor model for HTN in predicting risk and protection from HTN among Yup'ik people. METHODS: Using data from 1015 Yup'ik individuals residing in remote Southwestern Alaska, we explore age, sex, education, waist circumference, physical activity, tobacco, social support, and cultural identification in multinomial logistic regressions comparing pre-hypertension (pre-HTN; systolic 120 to 129 mm Hg), and hypertension (HTN; systolic > or = 130 mm Hg) to optimal blood pressure (opt-BP; systolic < 120 mm Hg). RESULTS: We find positive associations between age (2%, 5% greater odds respectively), waist circumference (3%, 5% greater odds respectively) and hypertension medication usage (60%, 85% greater odds respectively) with both pre-HTN and HTN. We also find men have 86% greater odds of pre-HTN, people with fasting blood glucose > or = 110 mg/dL have 52% increased odds of pre-HTN, and married persons have 19% lower odds of having pre-HTN compared to having opt-BP. Bicultural identification mitigates age related increases in BP and deleterious effects of low formal education. CONCLUSIONS: While model continuities are noted in our Yup'ik study, important points of divergence are also noted. Future research on cultural identification and social support has promising implications for guiding responsive interventions.
Predictors of health information-seeking behaviors in hispanics
The objective of this study was to examine factors predicting use of the Internet to seek health information among Hispanics in the Washington Heights and Inwood areas of New York City. Data were collected by community health workers through the Washington Heights/Inwood Informatics Infrastructure for Community-Centered Comparative Effectiveness Research (WICER) community survey and a random sample of 100 surveys was selected for analysis. Binary logistic regression (N=100) was used to examine predictors of online health information-seeking behaviors (HISBs) of respondent and household members (dependent variables). Younger age, better health status, and higher education level significantly predicted respondents' HISBs. Respondents' health status and education level also significantly predicted household members' HISBs.
Using the LOINC Semantic Structure to Integrate Community-based Survey Items into a Concept-based Enterprise Data Dictionary to Support Comparative Effectiveness Research
In designing informatics infrastructure to support comparative effectiveness research (CER), it is necessary to implement approaches for integrating heterogeneous data sources such as clinical data typically stored in clinical data warehouses and those that are normally stored in separate research databases. One strategy to support this integration is the use of a concept-oriented data dictionary with a set of semantic terminology models. The aim of this paper is to illustrate the use of the semantic structure of Clinical LOINC (Logical Observation Identifiers, Names, and Codes) in integrating community-based survey items into the Medical Entities Dictionary (MED) to support the integration of survey data with clinical data for CER studies.
The metabolic syndrome and subclinical carotid atherosclerosis: the Northern Manhattan Study
The metabolic syndrome (MetS) is a distinctive phenotype associated with an increased risk of vascular disease. Carotid plaque is a surrogate marker of subclinical atherosclerosis and a powerful predictor of vascular outcomes. The relationship between the MetS and subclinical atherosclerosis in multiethnic populations has not been well characterized. The authors have evaluated the association of the MetS with subclinical atherosclerosis among 1895 community residents from the Northern Manhattan Study (mean age, 68.0+/-9.7 years; 59% women; 25% black; 22% white; 51% Hispanic). The prevalence of the MetS was 41% (35% in men, 45% in women), and 57% of subjects had carotid plaque. In a multivariate-adjusted logistic regression model, the MetS was a significant predictor of plaque presence (odds ratio, 1.36; 95% confidence interval, 1.10-1.67). Additionally, the number of MetS components was significantly associated with plaque prevalence. Further studies are needed to understand the role of the MetS in the progression from subclinical to clinical atherosclerotic disease.
Design of a family study among high-risk Caribbean Hispanics: the Northern Manhattan Family Study
Stroke continues to kill disproportionately more Blacks and Hispanics than Whites in the United States. Racial/ethnic variations in the incidence of stroke and prevalence of stroke risk factors are probably explained by both genetic and environmental influences. Family studies can help identify genetic predisposition to stroke and potential stroke precursors. Few studies have evaluated the heritability of these stroke risk factors among non-White populations, and none have focused on Caribbean Hispanic populations. The aim of the Northern Manhattan Family Study (NOMAFS) is to investigate the gene-environment interaction of stroke risk factors among Caribbean Hispanics. The unique recruitment and methodologic approaches used in this study are relevant to the design and conduct of genetic aggregation studies to investigate complex genetic disorders in non-White populations. The aim of this paper is to describe the NOMAFS and report enrollment and characteristics of the participants. The NOMAFS will provide a data resource for the exploration of the genetic determinants of highly heritable stroke precursor phenotypes that are less complex than the stroke phenotype. Understanding the gene environment interaction is the critical next step toward the development of new and unique approaches to disease prevention and interventions.
Socioeconomic status and stroke mortality: refining the relationship
Mortality and causes of death after first ischemic stroke: the Northern Manhattan Stroke Study
OBJECTIVE: To analyze the early and long-term causes of death after first ischemic stroke in the multiethnic northern Manhattan community. METHODS: In the prospective, population-based Northern Manhattan Stroke Study, 980 patients with first ischemic stroke (mean age 70 years; 56% women; 49% Caribbean Hispanic, 31% black, 20% white) were followed for a mean of 3 years. Causes of death were classified as vascular (incident stroke, recurrent stroke, cardiac) or nonvascular. Life table analyses were used to assess mortality risks among different race-ethnic groups. Early (< or =1 month) vs long-term (> 1 month to 5 years) causes of death were compared. RESULTS: Among the 980 patients followed, 278 (28%) died; 47 (5%) died during the first month. Cumulative mortality risk was 5% at 1 month, 16% after 1 year, 29% after 3 years, and 41% after 5 years. The proportion of vascular deaths among all deaths was 75% at 1 month and 43% thereafter (p = 0.001). Stroke, either incident (53%) or recurrent (4%), caused early deaths in 57% and long-term deaths in 14% (p = 0.001). Overall mortality risks did not differ significantly among race-ethnic groups. However, the proportion of incident stroke-related early deaths was 85% in Caribbean Hispanic patients, 33% in white patients, and 25% in black patients (p = 0.002). CONCLUSIONS: Among patients with first ischemic stroke, incident stroke is the leading cause of early deaths. A large proportion of long-term deaths are nonvascular in origin. Despite similar overall mortality rates in race-ethnic groups, our data suggest a higher incident stroke-related early mortality among Caribbean Hispanics.
Lifestyle factors and stroke risk: exercise, alcohol, diet, obesity, smoking, drug use, and stress
Various lifestyle factors have been associated with increasing the risk of stroke. These include lack of exercise, alcohol, diet, obesity, smoking, drug use, and stress. Guidelines endorsed by the Centers for Disease Control and Prevention and the National Institutes of Health recommend that Americans should exercise for at least 30 minutes of moderately intense physical activity on most, and preferably all, days of the week. Recent epidemiologic studies have shown a U-shaped curve for alcohol consumption and coronary heart disease mortality, with low-to-moderate alcohol consumption associated with lower overall mortality. High daily dietary intake of fat is associated with obesity and may act as an independent risk factor or may affect other stroke risk factors such as hypertension, diabetes, hyperlipidemia, and cardiac disease. Homocysteine is another important dietary component associated with stroke risk, while other dietary stroke risk factors are thought to be mediated through the daily intake of several vitamins and antioxidants. Smoking, especially current smoking, is a crucial and extremely modifiable independent determinant of stroke. Despite the obstacles to the modification of lifestyle factors, health professionals should be encouraged to continue to identify such factors and help improve our ability to prevent stroke.
Predictors of resource use after acute hospitalization: the Northern Manhattan Stroke Study
OBJECTIVE: To determine demographic and clinical predictors of discharge destinations following acute care hospitalization for stroke in the community of northern Manhattan. METHODS: A group of 893 patients (mean age, 70 +/- 12 years; 56% women; 51% Hispanic, 30% African-American, 19% white) who survived acute care hospitalization for a first ischemic stroke were followed prospectively. Stroke severity was assessed by the NIH Stroke Scale and categorized as mild (< or = 5), moderate (6 to 13), and severe (> or = 14). Polytomous logistic regression was used to determine predictors for rehabilitation and nursing home placement versus returning home. RESULTS: Among the survivors of acute stroke care hospitalization, 611 (68%) patients were discharged to their homes, 168 (19%) to rehabilitation, and 114 (13%) to nursing homes. Patients with moderate and severe neurologic deficits had more than a threefold increased risk of being sent to a nursing home and more than an eightfold increased risk of being sent to rehabilitation. Age over 65 and cognitive impairment were associated with placement to a nursing home (age over 65: OR, 2.4; 95% CI, 1.0 to 5.6; cognitive impairment: OR, 2.9; 95%, CI 1.4 to 5.7), and rehabilitation (age over 65: OR, 1.8; 95% CI, 1.1 to 2.9; cognitive impairment: OR, 2.9; 95% CI, 1.4 to 5.7). CONCLUSION: Our results demonstrated that one-third of patients with acute stroke from the community of northern Manhattan required placement in a temporary or a long-term disability care institution following acute care hospitalization. Severity of stroke is an important factor that influences discharge planning following acute care hospitalization and its reduction can improve health care resource usage.
Stroke incidence among white, black, and Hispanic residents of an urban community: the Northern Manhattan Stroke Study
Stroke mortality is reported to be greater in blacks than in whites, but stroke incidence data for blacks and Hispanics are sparse. The aim of this study was to determine and compare stroke incidence rates among whites, blacks, and Hispanics living in the same urban community. A population-based incidence study was conducted to identify all cases of first stroke occurring in northern Manhattan, New York City, between July 1, 1993, and June 30, 1996. The population of this area was approximately 210,000 at that time, based on 1990 US Census data. Surveillance for hospitalized and nonhospitalized stroke consisted of daily screening of all admissions, discharges, and computed tomography logs at Columbia-Presbyterian Medical Center, the only hospital in the region, and review of discharge lists from outside hospitals, telephone surveys of random households, and contacts with community physicians, Visiting Nurses' Services, and community agencies. Stroke incidence increased with age and was greater in men than in women. The average annual age-adjusted stroke incidence rate at age > or =20 years, per 100,000 population, was 223 for blacks, 196 for Hispanics, and 93 for whites. Blacks had a 2.4-fold and Hispanics a twofold increase in stroke incidence compared with whites. Cerebral infarct accounted for 77 percent of all strokes, intracerebral hemorrhage for 17 percent, and subarachnoid hemorrhage for 6 percent. These data from the Northern Manhattan Stroke Study suggest that part of the reported excess stroke mortality among blacks in the United States may be a reflection of racial/ethnic differences in stroke incidence.
Testing the validity of the lacunar hypothesis: the Northern Manhattan Stroke Study experience
BACKGROUND/OBJECTIVE: Few studies have attempted to validate the "lacunar hypothesis." The accuracy of identifying lacunar and other nonlacunar mechanisms of infarction will be increasingly important in evaluating potential stroke treatments. The aim of this study was to determine the value of lacunar syndromes in predicting radiologic lacunes and the value of clinicoradiologic lacunes in predicting "lacunar infarction" as final stroke mechanism. METHODS: From 1990 to 1994, 591 patients with cerebral infarction, who were from northern Manhattan and over the age of 39, were prospectively examined. Data were collected on the admitting clinical syndrome (lacunar or nonlacunar) and brain imaging findings. Lacunar syndromes were categorized as pure motor hemiparesis (PMH), pure sensory syndrome (PSS), sensorimotor syndrome (SMS), ataxic-hemiparesis (A-H), and other lacunar syndromes. Brain imaging findings were classified as radiologic lacune or nonlacune. Positive predictive values, sensitivities, and specificities of lacunar syndromes for identifying radiologic lacunes were calculated. The final mechanism of infarction was determined after review of all the diagnostic tests and compared among the lacunar groups. RESULTS: Lacunar syndromes occurred in 225 cases. PMH was the most common lacunar syndrome, accounting for 45%, SMS 20%, A-H 18%, and PSS 7%. Lacunar syndromes had an overall positive predictive value (PPV) of 87% for detecting radiologic lacune: PSS 100%, A-H 95%, SMS 87%, and PMH 79%. Among the 195 patients who presented with a lacunar syndrome and had this condition confirmed radiologically, 147 were classified as having a final diagnosis of lacunar mechanism of infarction (PPV = 75%). Atherosclerosis accounted for 17 (9%), cardioembolism 10 (5%), cryptogenic 17 (9%), and other unusual causes 4 (2%). CONCLUSION: While lacunar syndromes, especially PSS and A-H, are highly predictive of lacune, in about one in four patients presenting with lacunar syndromes confirmed radiologically the condition is associated with nonlacunar mechanisms of infarction. Noninvasive neurovascular and cardiac evaluations are still warranted even among patients with lacunes.
Race-ethnic variability in etiologic fraction for stroke risk factors: The Northern Manhattan Stroke Study
Patent foremen ovale as a risk factor for ischemic stroke in a multiethnic population
Increased left atrial size is an independent risk factor for ischemic stroke
Serum potassium and ischemic stroke risk: Findings from the Northern Manhattan Stroke Study
Severe headache at stroke onset is an indicator of large vessel occlusive disease: The Northern Manhattan Stroke Study
Lack of association between social readjustment and ischemic stroke in the Northern Manhattan Stroke Study
Stroke severity is a predictor of early hospital arrival after stroke: The Northern Manhattan Stroke Study
Obesity is associated with endothelial dysfunction: A study in 843 community-acquired subjects
JOHN HENYRISM AND HYPERTENSION RISK AMONG HISPANICS.
DAYTIME SLEEPINESS AND RISK OF STROKE AND VASCULAR DISEASE: FINDINGS FROM THE NORTHERN MANHATTAN STUDY
Race-ethnic Differentials Time and Acute Stroke Emergency Presentation: The ASPIRE Study
Predictors of Discharge Location and Long-Term Living Destination Following Acute Care Hospitalization for Intracerebral Hemorrhage: The DECIPHER Study
Race/ethnicity Modifies Increased Recurrent Event Risk For Female Stroke Survivors
Health Literacy, Knowledge and Competency: Lessons from the SWIFT Community Study
Racial Disparities among Incident Ischemic Stroke Cases in the District of Columbia: the ASPIRE Study
Factoring Influencing Fruit and Vegetable Intake and Associations with Cardiovascular Disease Risk Factors: The Grenada Heart Project
Examining Relationships between Stroke Risk Perception and Locus of Control: The SWIFT Community Study
Racial/ethnic Differences in Psychological Distress after Stroke
Relationship of 6-month functional outcome and stroke severity: Implications for acute stroke trials from the Northern Manhattan Stroke Study
Post-Stroke Rehabilitation: Differing Perspectives among Patients and Providers
Subarachnoid hemorrhage incidence among Whites, Blacks and Caribbean Hispanics: the Northern Manhattan Study
American blacks and Hispanics may have a greater incidence of subarachnoid hemorrhage (SAH) than whites, but incidence data are scant. We used an active hospital and community surveillance program and autopsy reports to identify incident SAH cases among white, black and Hispanic adults living in Northern Manhattan between July 1993 and June 1997. The annual incidence adjusted for age and sex to the 1990 US Census was 9.7 per 100,000 (95% CI 7.5-12.0). Compared with whites (9 cases, age- and sex-adjusted annual incidence 8.2 per 100,000), the rate ratio of SAH was 1.3 (95% CI 0.7-2.4) for Hispanics (34 cases, incidence 10.9), and 1.6 (95% CI 0.8-2.8) for blacks (9 cases, incidence 12.8). The 30-day case fatality rate was 26%. Risk of death increased significantly with age and severity at onset but was not influenced by gender or race-ethnicity
Short sleep duration as a risk factor for hypertension: analyses of the first National Health and Nutrition Examination Survey
Depriving healthy subjects of sleep has been shown to acutely increase blood pressure and sympathetic nervous system activity. Prolonged short sleep durations could lead to hypertension through extended exposure to raised 24-hour blood pressure and heart rate, elevated sympathetic nervous system activity, and increased salt retention. Such forces could lead to structural adaptations and the entrainment of the cardiovascular system to operate at an elevated pressure equilibrium. Sleep disorders are associated with cardiovascular disease, but we are not aware of any published prospective population studies that have shown a link between short sleep duration and the incidence of hypertension in subjects without apparent sleep disorders. We assessed whether short sleep duration would increase the risk for hypertension incidence by conducting longitudinal analyses of the first National Health and Nutrition Examination Survey (n=4810) using Cox proportional hazards models and controlling for covariates. Hypertension incidence (n=647) was determined by physician diagnosis, hospital record, or cause of death over the 8- to 10-year follow-up period between 1982 and 1992. Sleep durations of < or =5 hours per night were associated with a significantly increased risk of hypertension (hazard ratio, 2.10; 95% CI, 1.58 to 2.79) in subjects between the ages of 32 and 59 years, and controlling for the potential confounding variables only partially attenuated this relationship. The increased risk continued to be significant after controlling for obesity and diabetes, which was consistent with the hypothesis that these variables would act as partial mediators. Short sleep duration could, therefore, be a significant risk factor for hypertension
The incidence of deep and lobar intracerebral hemorrhage in whites, blacks, and Hispanics
BACKGROUND: Black and Hispanic Americans have a greater risk of primary intracerebral hemorrhage (ICH) than whites. Deep ICH is most often associated with hypertension, while lobar ICH is associated with cerebral amyloid angiopathy. The authors conducted a population-based incidence study to directly compare the incidence of deep vs lobar ICH in all three race-ethnic groups. METHODS: The authors used an active hospital and community surveillance program and autopsy reports to identify incident ICH cases among white, black, and Caribbean Hispanic adults in Northern Manhattan between July 1993 and June 1997. Incidence rates were adjusted for age and sex to the 1990 US Census. CIs for risk ratios (RR) were calculated with Byar's chi2 approximation of the Poisson distribution. RESULTS: The authors identified 155 cases of ICH for an annual incidence of 30.9/100,000 (26.7 to 35.0). Men had a higher risk of ICH than women (RR 1.5, 95% CI 1.2 to 1.8), driven entirely by the incidence of deep ICH (RR 1.8) rather than lobar ICH (RR 1.0). Compared with whites, RR for blacks was all ICH 3.8 (2.2 to 8.9), deep 4.8 (2.3 to 21.1), lobar 2.8 (1.2 to 14.4); RR for Hispanics was all 2.6 (1.4 to 6.1), deep 3.7 (1.7 to 16.5), lobar 1.4 (0.4 to 7.4). CONCLUSIONS: ICH is a heterogeneous disease with deep and lobar subtypes distinguishable on an epidemiologic basis. The different patterns of these two subtypes in our race-ethnically diverse population lend credence to the notion that ICH should no longer be treated as a single entity
Lacunar infarct or deep intracerebral hemorrhage: who gets which? The Northern Manhattan Study
Lacunar infarcts (LACs) and deep intracerebral hemorrhages (DICHs) occur in the same structures and may result from the same pathology. It is unclear why one patient has an LAC while another has DICH. We compared LAC to DICH cases derived from a population-based incidence study. In multivariate analysis, LAC cases were significantly older, more likely to have diabetes, and had higher cholesterol than DICH cases
Guidelines for the Primary Prevention of Stroke: A Statement for Healthcare Professionals From the American Heart Association/American Stroke Association
The aim of this updated statement is to provide comprehensive and timely evidence-based recommendations on the prevention of stroke among individuals who have not previously experienced a stroke or transient ischemic attack. Evidence-based recommendations are included for the control of risk factors, interventional approaches to atherosclerotic disease of the cervicocephalic circulation, and antithrombotic treatments for preventing thrombotic and thromboembolic stroke. Further recommendations are provided for genetic and pharmacogenetic testing and for the prevention of stroke in a variety of other specific circumstances, including sickle cell disease and patent foramen ovale.
Online health information seeking behaviors of Hispanics in New York City: a community-based cross-sectional study
BACKGROUND: The emergence of the Internet has increased access to health information and can facilitate active individual engagement in health care decision making. Hispanics are the fastest-growing minority group in the United States and are also the most underserved in terms of access to online health information. A growing body of literature has examined correlates of online health information seeking behaviors (HISBs), but few studies have included Hispanics. OBJECTIVE: The specific aim of this descriptive, correlational study was to examine factors associated with HISBs of Hispanics. METHODS: The study sample (N=4070) was recruited from five postal zip codes in northern Manhattan for the Washington Heights Inwood Informatics Infrastructure for Comparative Effectiveness Research project. Survey data were collected via interview by bilingual community health workers in a community center, households, and other community settings. Data were analyzed using bivariate analyses and logistic regression. RESULTS: Among individual respondents, online HISBs were significantly associated with higher education (OR 3.03, 95% CI 2.15-4.29, P<.001), worse health status (OR 0.42, 95% CI 0.31-0.57, P<.001), and having no hypertension (OR 0.60, 95% CI 0.43-0.84, P=.003). Online HISBs of other household members were significantly associated with respondent factors: female gender (OR 1.60, 95% CI 1.22-2.10, P=.001), being younger (OR 0.75, 95% CI 0.62-0.90, P=.002), being married (OR 1.36, 95% CI 1.09-1.71, P=.007), having higher education (OR 1.80, 95% CI 1.404-2.316, P<.001), being in worse health (OR 0.59, 95% CI 0.46-0.77, P<.001), and having serious health problems increased the odds of their household members' online HISBs (OR 1.83, 95% CI 1.29-2.60, P=.001). CONCLUSIONS: This large-scale community survey identified factors associated with online HISBs among Hispanics that merit closer examination. To enhance online HISBs among Hispanics, health care providers and policy makers need to understand the cultural context of the Hispanic population. Results of this study can provide a foundation for the development of informatics-based interventions to improve the health of Hispanics in the United States.
Sleep duration is associated with white matter hyperintensity volume in older adults: the Northern Manhattan Study
Self-reports of long or short sleep durations have indicated an association with cardiovascular morbidity and mortality, but there are limited data evaluating their association with white matter hyperintensity volume (WMHV), a marker of cerebral small vessel disease. We conducted a cross-sectional analysis of self-reported sleep duration to test for a correlation with white matter hyperintensities, measured by quantitative magnetic resonance imaging (MRI), in the Northern Manhattan Study. We used multivariable linear regression models to assess associations between both short (<6 h) and long (>/=9 h) sleep durations and log-transformed WMHV, adjusting for demographic, behavioural and vascular risk factors. A total of 1244 participants, mean age 70 +/- 9 years, 61% women and 68% Hispanics were analysed with magnetic resonance brain imaging and self-reported sleep duration. Short sleep was reported by 23% (n = 293) and long sleep by 10% (n = 121) of the sample. Long sleep (beta = 0.178; P = 0.035), but not short sleep (beta = -0.053; P = 0.357), was associated with greater log-WMHV in fully adjusted models. We observed an interaction between sleep duration, diabetes mellitus and log-WMHV (P = 0.07). In fully adjusted models, stratified analysis showed that long sleep duration was associated with greater WMHV only in those with diabetes (beta = 0.78; P = 0.0314), but not in those without diabetes (beta = 0.022; P = 0.2), whereas short sleep was not associated with white matter hyperintensities in those with or without diabetes. In conclusion, long sleep duration was associated with a greater burden of white matter lesions in this stroke-free urban sample. The association was seen mainly among those with diabetes mellitus.
Moving Towards a More Comprehensive Investigation of Racial/Ethnic Differences in Cognitive Disability Among US Adults
We examined racial/ethnic differences in cognitive disability and the contribution of sociodemographic factors to these differences. Using logistic regression, we measured the association between race/ethnicity and cognitive disability after adjustment for sociodemographic covariates, including agegroup, sex, education, nativity, region, marital status, and occupation among 2009 American Community Survey respondents (>/=25 years). Effect modification was also explored. Cognitive disability was self-reported by 6 % of respondents. The proportion with cognitive disability was highest for Blacks and Native American/Pacific Islanders. Statistically significant effect modification was observed for all sociodemographic covariates, except sex. Although most sociodemographic modifiers revealed a more convoluted relationship between race/ethnicity and cognitive disability, the cognitive benefits of higher education, foreign born nativity, and top-tier occupations were observed among most racial/ethnic groups. The observed interplay between sociodemographics and race/ethnicity highlight a complex relationship between race/ethnicity and cognitive disability. Future research should examine mechanisms for this induced complexity.
Methodology for a community-based stroke preparedness intervention: the Acute Stroke Program of Interventions Addressing Racial and Ethnic Disparities Study
BACKGROUND AND PURPOSE: Acute stroke education has focused on stroke symptom recognition. Lack of education about stroke preparedness and appropriate actions may prevent people from seeking immediate care. Few interventions have rigorously evaluated preparedness strategies in multiethnic community settings. METHODS: The Acute Stroke Program of Interventions Addressing Racial and Ethnic Disparities (ASPIRE) project is a multilevel program using a community-engaged approach to stroke preparedness targeted to underserved black communities in the District of Columbia. This intervention aimed to decrease acute stroke presentation times and increase intravenous tissue-type plasminogen activator utilization for acute ischemic stroke. RESULTS: Phase 1 included (1) enhancement of focus of emergency medical services on acute stroke; (2) hospital collaborations to implement and enrich acute stroke protocols and transition District of Columbia hospitals toward primary stroke center certification; and (3) preintervention acute stroke patient data collection in all 7 acute care District of Columbia hospitals. A community advisory committee, focus groups, and surveys identified perceptions of barriers to emergency stroke care. Phase 2 included a pilot intervention and subsequent citywide intervention rollout. A total of 531 community interventions were conducted, reaching >10,256 participants; 3289 intervention evaluations were performed, and 19,000 preparedness bracelets and 14,000 stroke warning magnets were distributed. Phase 3 included an evaluation of emergency medical services and hospital processes for acute stroke care and a year-long postintervention acute stroke data collection period to assess changes in intravenous tissue-type plasminogen utilization. CONCLUSIONS: We report the methods, feasibility, and preintervention data collection efforts of the ASPIRE intervention. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00724555.
Multiple metabolic risk factors and mammographic breast density
PURPOSE: We examined whether obesity and a history of diabetes, hypertension, and elevated cholesterol, individually and in combination, are associated with breast density, a strong risk factor for breast cancer. METHODS: We measured percent density and dense area using a computer-assisted method (n = 191; age range = 40-61 years). We used linear regression models to examine the associations of each metabolic condition and the number of metabolic conditions (zero, one, two, and three or four conditions) with breast density. RESULTS: Among individual metabolic conditions, only high blood cholesterol was inversely associated with percent density (beta = -5.4, 95% confidence interval [CI]: -8.5, -2.2) and dense area (beta = -6.7, 95% CI = -11.1, -2.4). Having multiple metabolic conditions was also associated with lower breast density, with two conditions and three or four conditions versus zero conditions associated with 6.4% (95% CI: -11.2, -1.6) and 7.4% (95% CI: -12.9, -1.9) reduction in percent density and with 6.5 cm(2) (95% CI: -13.1, -0.1) and 9.5 cm(2) (95% CI: -17.1, -1.9) decrease in dense area. CONCLUSIONS: A history of high blood cholesterol and multiple metabolic conditions were associated with lower relative and absolute measures of breast density. The positive association between metabolic abnormalities and breast cancer risk may be driven by pathways unrelated to mammographic breast density.
Association between sleep duration and the mini-mental score: the Northern Manhattan study
BACKGROUND: Short and long sleep duration are associated with increased mortality and worse global cognitive function, but is unclear if these relations persist after accounting for the risk of sleep disordered breathing (SDB). The aim of our study is determine the association between short and long sleep duration with worse global cognitive function in a racially/ethnically diverse elderly cohort. METHODS: We examined sleep hours and global cognitive function cross-sectionally within the population-based Northern Manhattan Study cohort. We conducted nonparametric and logistic regression to examine associations between continuous, short (< 6 h) and long (>/= 9 h) sleep hours with performance on the Mini Mental State Examination (MMSE). RESULTS: There were 927 stroke-free participants with data on self-reported sleep hours and MMSE scores (mean age 75 +/- 9 years, 61% women, 68% Hispanics). The median (interquartile range) MMSE was 28 (10-30). Sleep hours (centered at 7 h) was associated with worse MMSE (beta = -0.01; SE [0.004], p = 0.0113) adjusting for demographics, vascular risk factors, medications, and risk for SDB. Reporting long sleep (>/= 9 h) compared to 6 to 8 h of sleep (reference) was significantly and inversely associated with MMSE (adjusted beta = -0.06; SE [0.03], p = 0.012), while reporting short sleep was not significantly associated with MMSE performance. Long sleep duration was also associated with low MMSE score when dichotomized (adjusted OR: 2.4, 95% CI: 1.1-5.0). CONCLUSION: In this cross-sectional analysis among an elderly community cohort, long sleep duration was associated with worse MMSE performance.
Education strategies for stroke prevention
Poor long-term blood pressure control after intracerebral hemorrhage
BACKGROUND AND PURPOSE: Hypertension is the most important risk factor associated with intracerebral hemorrhage. We explored racial differences in blood pressure (BP) control after intracerebral hemorrhage and assessed predictors of BP control at presentation, 30 days, and 1 year in a prospective cohort study. METHODS: Subjects with spontaneous intracerebral hemorrhage were identified from the DiffErenCes in the Imaging of Primary Hemorrhage based on Ethnicity or Race (DECIPHER) Project. BP was compared by race at each time point. Multivariable linear regression was used to determine predictors of presenting mean arterial pressure, and longitudinal linear regression was used to assess predictors of mean arterial pressure at follow-up. RESULTS: A total of 162 patients were included (mean age, 59 years; 53% male; 77% black). Mean arterial pressure at presentation was 9.6 mm Hg higher in blacks than whites despite adjustment for confounders (P=0.065). Fewer than 20% of patients had normal BP (<120/80 mm Hg) at 30 days or 1 year. Although there was no difference at 30 days (P=0.331), blacks were more likely than whites to have Stage I/II hypertension at 1 year (P=0.036). Factors associated with lower mean arterial pressure at follow-up in multivariable analysis were being married at baseline (P=0.032) and living in a facility (versus personal residence) at the time of BP measurement (P=0.023). CONCLUSIONS: Long-term BP control is inadequate in patients after intracerebral hemorrhage, particularly in blacks. Further studies are needed to understand the role of social support and barriers to control to identify optimal approaches to improve BP in this high-risk population.
Daytime sleepiness and risk of stroke and vascular disease: findings from the Northern Manhattan Study (NOMAS)
BACKGROUND: Recent studies have suggested that poor quality and diminished quantity of sleep may be independently linked to vascular events although prospective and multiethnic studies are limited. This study aimed to explore the relationship between daytime sleepiness and the risk of ischemic stroke and vascular events in an elderly, multiethnic prospective cohort. METHODS AND RESULTS: As part of the Northern Manhattan Study, the Epworth Sleepiness Scale was collected during the 2004 annual follow-up. Daytime sleepiness was trichotomized using previously reported cut points of no dozing, some dozing, and significant dozing. Subjects were followed annually for a mean of 5.1 years. Cox proportional hazards models were used to calculate hazard ratios and 95% confidence intervals for stroke, myocardial infarction, and death outcomes. We obtained the Epworth Sleepiness Scale on 2088 community residents. The mean age was 73.5 +/- 9.3 years; 64% were women; 17% were white, 20% black, 60% Hispanic, and 3% were other. Over 44% of the cohort reported no daytime dozing, 47% some dozing, and 9% significant daytime dozing. Compared with those reporting no daytime dozing, individuals reporting significant dozing had an increased risk of ischemic stroke (hazard ratio, 2.74 [95% confidence interval, 1.38-5.43]), all stroke (3.00 [1.57-5.73]), the combination of ischemic stroke, myocardial infarction, and vascular death (2.38 [1.50-3.78]), and all vascular events (2.48 [1.57-3.91]), after adjusting for medical comorbidities. CONCLUSIONS: Daytime sleepiness is an independent risk factor for stroke and other vascular events. These findings suggest the importance of screening for sleep problems at the primary care level.
Research data collection methods: from paper to tablet computers
BACKGROUND: Primary data collection is a critical activity in clinical research. Even with significant advances in technical capabilities, clear benefits of use, and even user preferences for using electronic systems for collecting primary data, paper-based data collection is still common in clinical research settings. However, with recent developments in both clinical research and tablet computer technology, the comparative advantages and disadvantages of data collection methods should be determined. OBJECTIVE: To describe case studies using multiple methods of data collection, including next-generation tablets, and consider their various advantages and disadvantages. MATERIALS AND METHODS: We reviewed 5 modern case studies using primary data collection, using methods ranging from paper to next-generation tablet computers. We performed semistructured telephone interviews with each project, which considered factors relevant to data collection. We address specific issues with workflow, implementation and security for these different methods, and identify differences in implementation that led to different technology considerations for each case study. RESULTS AND DISCUSSION: There remain multiple methods for primary data collection, each with its own strengths and weaknesses. Two recent methods are electronic health record templates and next-generation tablet computers. Electronic health record templates can link data directly to medical records, but are notably difficult to use. Current tablet computers are substantially different from previous technologies with regard to user familiarity and software cost. The use of cloud-based storage for tablet computers, however, creates a specific challenge for clinical research that must be considered but can be overcome.
Safety of thrombolysis in patients over the age of 80
BACKGROUND: The safety of intravenous thrombolysis (IVT) in patients with acute ischemic stroke over the age of 80 is unclear. We hypothesized that patients over the age of 80 can be safely treated with IVT. METHODS: Admission and discharge data were collected on all patients at a single tertiary care center presenting within 12 hours of onset. Collected data included treatment with IVT, demographics, pretreatment National Institutes of Health Stroke Scale score, length of stay, mortality, and discharge disposition. Analyses were restricted to patients over the age of 80, and the primary outcome was in-hospital mortality. Logistic regression was used to examine whether IVT was associated with mortality. RESULTS: Between January 1, 2005 and May 30, 2010, 112 patients over the age of 80 presented within 3 hours of ischemic stroke onset, and 31 received IVT. There were 15 deaths. In multivariable models adjusted for age, sex, race-ethnicity, and National Institutes of Health Stroke Scale, treatment with IVT, compared with no treatment, was not associated with in-hospital death (adjusted odds ratio, 1.2; 95% confidence interval, 0.3-4.3). CONCLUSIONS: Treating ischemic stroke patients over 80 years with IVT was not associated with an increase in mortality in an urban tertiary care center.
Mediterranean diet and white matter hyperintensity volume in the Northern Manhattan Study
OBJECTIVE: To examine the association between a Mediterranean-style diet (MeDi) and brain magnetic resonance imaging white matter hyperintensity volume (WMHV). DESIGN: A cross-sectional analysis within a longitudinal population-based cohort study. A semiquantitative food frequency questionnaire was administered, and a score (range, 0-9) was calculated to reflect increasing similarity to the MeDi pattern. SETTING: The Northern Manhattan Study. PARTICIPANTS: A total of 1091 participants, of whom 966 had dietary information (mean age, 72 years; 59.3% women, 64.6% Hispanic, 15.6% white, and 17.5% black). MAIN OUTCOME MEASURES: The WMHV was measured by quantitative brain magnetic resonance imaging. Linear regression models were constructed to examine the association between the MeDi score and the log-transformed WMHV as a proportion of total cranial volume, controlling for sociodemographic and vascular risk factors. RESULTS: On the MeDi scale, 11.6% scored 0 to 2, 15.8% scored 3, 23.0% scored 4, 23.5% scored 5, and 26.1% scored 6 to 9. Each 1-point increase in MeDi score was associated with a lower log WMHV (beta = -.04, P = .01). The only MeDi score component that was an independent predictor of WMHV was the ratio of monounsaturated to saturated fat (beta = -.20, P = .001). CONCLUSIONS: A MeDi was associated with a lower WMHV burden, a marker of small vessel damage in the brain. However, white matter hyperintensities are etiologically heterogenous and can include neurodegeneration. Replication by other population-based studies is needed.
Race-ethnic differences of sleep symptoms in an elderly multi-ethnic cohort: the Northern Manhattan Study
BACKGROUND: Sleep disorders are associated with stroke and may vary among elderly Hispanics, Blacks and Whites. We evaluated differences in sleep symptoms by race-ethnicity in an elderly population-based urban community sample. METHODS: Snoring, daytime sleepiness and reported sleep duration were ascertained by standardized interviews as a part of the Northern Manhattan Study, a prospective cohort study of vascular risk factors and stroke risk in a multi-ethnic urban population. Sleep symptoms were compared amongst race-ethnic groups using logistic regression models. RESULTS: A total of 1,964 stroke-free participants completed sleep questionnaires. The mean age was 75 +/- 9 years, with 37% men, with 60% Hispanics, 21% Blacks and 19% Whites. In models adjusted for demographic and vascular risk factors, Hispanics had increased odds of frequent snoring (odds ratio, OR: 3.6, 95% confidence interval, CI: 2.3-5.8) and daytime sleepiness (OR: 2.8, 95% CI: 1.7-4.5) compared to White participants. Hispanics were more likely to report long sleep (>/= 9 h of sleep, OR: 1.8, 95% CI: 1.1-3.1). There was no difference in sleep symptoms between Black and White participants. CONCLUSION: In this cross-sectional analysis among an elderly community cohort, snoring, sleepiness and long sleep duration were more common in Hispanics. Sleep symptoms may be surrogate markers for an underlying sleep disorder which may be associated with an elevated risk of stroke and may be modified by clinical intervention.
Too good to treat? Outcomes in patients not receiving thrombolysis due to mild deficits or rapidly improving symptoms
INTRODUCTION: Among ischemic stroke patients arriving within the treatment window, rapidly improving symptoms or having a mild deficit (i.e. too good to treat) is a common reason for exclusion. Several studies have reported poor outcomes in this group. We addressed the question of early neurological deterioration in too good to treat patients in a larger prospective cohort study. METHODS: Admission and discharge information were collected prospectively in acute stroke patients who presented to the emergency room within three-hours from onset. The primary outcome measure was change in the National Institutes of Health Stroke Scale from baseline to discharge. Secondary outcomes were discharge National Institutes of Health Stroke Scale >4, not being discharged home, and discharge modified Rankin scale. RESULTS: Of 355 patients who presented within three-hours, 127 (35.8%) had too good to treat listed as the only reason for not receiving thrombolysis, with median admission National Institutes of Health Stroke Scale = 1 (range = 0 to 19). At discharge, seven (5.5%) showed a worsening of National Institutes of Health Stroke Scale >/=1, and nine (7.1%) had a National Institutes of Health Stroke Scale >4. When excluding prior stroke (remaining n = 97), discharge status was even more benign: only five (5.2%) had a discharge National Institutes of Health Stroke Scale >4, and two (2.1%) patients were not discharged home. CONCLUSION: We found that a small proportion of patients deemed too good to treat will have early neurological deterioration, in contrast to other studies. Decisions about whether to treat mild stroke patients depend on the outcome measure chosen, particularly when considering discharge disposition among patients who have had prior stroke. The decision to thrombolyze may ultimately rest on the nature of the presentation and deficit.
Mediterranean-style diet and risk of ischemic stroke, myocardial infarction, and vascular death: the Northern Manhattan Study
BACKGROUND: A dietary pattern common in regions near the Mediterranean appears to reduce risk of all-cause mortality and ischemic heart disease. Data on blacks and Hispanics in the United States are lacking, and to our knowledge only one study has examined a Mediterranean-style diet (MeDi) in relation to stroke. OBJECTIVE: In this study, we examined an MeDi in relation to vascular events. DESIGN: The Northern Manhattan Study is a population-based cohort to determine stroke incidence and risk factors (mean +/- SD age of participants: 69 +/- 10 y; 64% women; 55% Hispanic, 21% white, and 24% black). Diet was assessed at baseline by using a food-frequency questionnaire in 2568 participants. A higher score on a 0-9 scale represented increased adherence to an MeDi. The relation between the MeDi score and risk of ischemic stroke, myocardial infarction (MI), and vascular death was assessed with Cox models, with control for sociodemographic and vascular risk factors. RESULTS: The MeDi-score distribution was as follows: 0-2 (14%), 3 (17%), 4 (22%), 5 (22%), and 6-9 (25%). Over a mean follow-up of 9 y, 518 vascular events accrued (171 ischemic strokes, 133 MIs, and 314 vascular deaths). The MeDi score was inversely associated with risk of the composite outcome of ischemic stroke, MI, or vascular death (P-trend = 0.04) and with vascular death specifically (P-trend = 0.02). Moderate and high MeDi scores were marginally associated with decreased risk of MI. There was no association with ischemic stroke. CONCLUSIONS: Higher consumption of an MeDi was associated with decreased risk of vascular events. Results support the role of a diet rich in fruit, vegetables, whole grains, fish, and olive oil in the promotion of ideal cardiovascular health.
The metabolic syndrome and cognitive performance: the Northern Manhattan Study
BACKGROUND: The metabolic syndrome (MetS) is a risk factor for diabetes, stroke, myocardial infarction, and increased mortality, and has been associated with cognition in some populations. We hypothesized that MetS would be associated with lower Mini-Mental State Examination (MMSE) scores in a multi-ethnic population, and that MetS is a better predictor of cognition than its individual components or diabetes. METHODS: We conducted a cross-sectional analysis among 3,150 stroke-free participants. MetS was defined by the modified National Cholesterol Education Program guidelines-Adult Treatment Panel III (NCEP-ATPIII) criteria. Linear regression and polytomous logistic regression estimated the association between MMSE score and MetS, its individual components, diabetes, and inflammatory biomarkers. RESULTS: MetS was inversely associated with MMSE score (unadjusted beta = -0.67; 95% CI -0.92, -0.41). Adjusting for potential confounders, MetS was associated with lower MMSE score (adjusted beta = -0.24; 95% CI -0.47, -0.01), but its individual components and diabetes were not. Those with MetS were more likely to have an MMSE score of <18 than a score of >/= 24 (adjusted OR = 1.94; 95% CI 1.26, 3.01). There was an interaction between MetS and race-ethnicity, such that MetS was associated with lower MMSE score among non-Hispanic whites and Hispanics but not non-Hispanic blacks. CONCLUSIONS: MetS was associated with lower cognition in a multi-ethnic population. Further studies of the effect of MetS on cognition are warranted, and should account for demographic differences.
Perception of recurrent stroke risk among black, white and Hispanic ischemic stroke and transient ischemic attack survivors: the SWIFT study
OBJECTIVES: Risk modification through behavior change is critical for primary and secondary stroke prevention. Theories of health behavior identify perceived risk as an important component to facilitate behavior change; however, little is known about perceived risk of vascular events among stroke survivors. METHODS: The SWIFT (Stroke Warning Information and Faster Treatment) study includes a prospective population-based ethnically diverse cohort of ischemic stroke and transient ischemic attack survivors. We investigate the baseline relationship between demographics, health beliefs, and knowledge on risk perception. Regression models examined predictors of inaccurate perception. RESULTS: Only 20% accurately estimated risk, 10% of the participants underestimated risk, and 70% of the 817 study participants significantly overestimated their risk for a recurrent stroke. The mean perceived likelihood of recurrent ischemic stroke in the next 10 years was 51 +/- 7%. We found no significant differences by race-ethnicity with regard to accurate estimation of risk. Inaccurate estimation of risk was associated with attitudes and beliefs [worry (p < 0.04), fatalism (p < 0.07)] and memory problems (p < 0.01), but not history or knowledge of vascular risk factors. CONCLUSION: This paper provides a unique perspective on how factors such as belief systems influence risk perception in a diverse population at high stroke risk. There is a need for future research on how risk perception can inform primary and secondary stroke prevention.
Race-ethnic differences in the association between lipid profile components and risk of myocardial infarction: The Northern Manhattan Study
OBJECTIVE: The aim of this study was to explore race-ethnic differences in the association between plasma lipid components and risk of incident myocardial infarction (MI). DESIGN/METHODS: As part of the Northern Manhattan Study, 2,738 community residents without cardiovascular disease were prospectively evaluated. Baseline fasting blood samples were collected, and lipid panel components were analyzed as continuous and categorical variables. Cox proportional hazards models were used to calculate HRs and 95% CIs for incident MI after adjusting for demographic and cardiovascular risk factors. RESULTS: The mean age was 68.8 +/- 10.4 years; 36.7% were men. Of the participants, 19.9% were non-Hispanic white; 24.9%, non-Hispanic black; and 52.8%, Hispanic (>80% from the Caribbean). Hispanics had lower mean high-density lipoprotein cholesterol (HDL-C) and higher triglycerides (TG)/HDL-C. During a mean 8.9 years of follow-up, there were 163 incident MIs. In the whole cohort, all lipid profile components were associated with risk of MI in the expected directions. However, HDL-C (adjusted HR per 10 mg/dL increase 0.93, 95% CI 0.76-1.12) and TG/HDL-C >2 (adjusted HR 0.89, 95% CI 0.51-1.55) were not predictive of MI among Hispanics but were predictive among non-Hispanic blacks and whites. Triglycerides/HDL-C per unit increase was associated with an 8% higher risk of MI among Hispanics (adjusted HR 1.08, 95% CI 1.04-1.12). CONCLUSIONS: In Hispanics, low HDL-C and TG/HDL-C >2 were not associated with MI risk. Our data suggest that a different TG/HDL ratio cutoff may be needed among Hispanics to predict MI risk.
Association between social isolation and left ventricular mass
BACKGROUND: Social isolation is associated with progression of cardiovascular disease, with the most socially isolated patients being at increased risk. Increased left ventricular mass is a predictor of cardiovascular morbidity and mortality. It is not yet clear whether social isolation is a determinant of increased left ventricular mass. METHODS: We performed a cross-sectional study of Northern Manhattan Study participants who were free of clinical cardiovascular disease and had obtained transthoracic echocardiograms (n=2021) and a baseline questionnaire on social habits. Social isolation was defined as the lack of friendship networks (knowing fewer than 3 people well enough to visit within their homes). Echocardiographic left ventricular mass was indexed to height(2.7), analyzed as a continuous variable and compared between exposure groups. RESULTS: The prevalence of social isolation was 13.5%. The average left ventricular mass was significantly higher (50.2 gm/m(2.7)) in those who were, as compared with those who were not (47.6 gm/m(2.7)), socially isolated (P<.05). Higher prevalence of social isolation was found among those less educated, uninsured, or unemployed. There were no significant race-ethnic differences in the prevalence of social isolation. In multivariate analysis, there was a trend toward an association between social isolation and increased left ventricular mass in the total cohort (P=.09). Among Hispanics, social isolation was significantly associated with greater left ventricular mass. Hispanics who were socially isolated averaged 3.9 gm/ht(2.7) higher left ventricular mass compared with those not socially isolated (P=.002). This relationship was not present among non-Hispanic blacks or whites. CONCLUSION: In this urban tri-ethnic cohort, social isolation was prevalent and associated with indices of low socioeconomic status. Hispanics who were socially isolated had a greater risk for increased left ventricular mass.
Social network types and acute stroke preparedness behavior
OBJECTIVES: Presence of informal social networks has been associated with favorable health and behaviors, but whether different types of social networks impact on different health outcomes remains largely unknown. We examined the associations of different social network types (marital dyad, household, friendship, and informal community networks) with acute stroke preparedness behavior. We hypothesized that marital dyad best matched the required tasks and is the most effective network type for this behavior. METHODS: We collected in-person interview and medical record data for 1,077 adults diagnosed with stroke and transient ischemic attack. We used logistic regression analyses to examine the association of each social network with arrival at the emergency department (ED) within 3 h of stroke symptoms. RESULTS: Adjusting for age, race-ethnicity, education, gender, transportation type to ED and vascular diagnosis, being married or living with a partner was significantly associated with early arrival at the ED (odds ratio = 2.0, 95% confidence interval: 1.2-3.1), but no significant univariate or multivariate associations were observed for household, friendship, and community networks. CONCLUSIONS: The marital/partnership dyad is the most influential type of social network for stroke preparedness behavior.
Insulin resistance and risk of ischemic stroke among nondiabetic individuals from the northern Manhattan study
BACKGROUND: Whether insulin resistance predicts ischemic stroke (IS) is still a matter of debate. OBJECTIVE: To determine the association between insulin resistance (IR) and risk of first ischemic stroke in a large, multiethnic, stroke-free cohort without diabetes. DESIGN: Prospective, population-based cohort study. SETTING: Longitudinal epidemiologic study. PARTICIPANTS: A cohort of 1509 nondiabetic participants from the Northern Manhattan Study (mean [SD] age, 11  years; 64.2% women; 58.9% Hispanics). MAIN OUTCOME MEASURES: Insulin sensitivity, expressed by the homeostasis model assessment (HOMA) of insulin sensitivity (HOMA index = [fasting insulin x fasting glucose] / 22.5). Insulin resistance was defined by a HOMA-IR index in the top quartile (Q4). Cox proportional hazards models were used to determine the effect of HOMA-IR on the risk of incident IS, myocardial infarction (MI), vascular death, and combined outcomes (IS, MI, and vascular death). RESULTS: The mean (SD) HOMA-IR was 2.3 (2.1), and Q4 was at least 2.8. During mean follow-up of 8.5 years, vascular events occurred in 180 participants; 46 had fatal or nonfatal IS, 45 had fatal or nonfatal MI, and 121 died of vascular causes. The HOMA-IR Q4 vs less than Q4 significantly predicted the risk of IS only (adjusted hazard ratio, 2.83; 95% confidence interval, 1.34-5.99) but not other vascular events. This effect was independent of sex, race/ethnicity, traditional vascular risk factors, and metabolic syndrome and its components. CONCLUSIONS: Insulin resistance estimated using the HOMA is a marker of increased risk of incident stroke in nondiabetic individuals. These findings emphasize the need to better characterize individuals at increased risk for IS and the potential role of primary preventive therapies targeted at IR.
Identifying interdisciplinary research priorities to prevent and treat pediatric obesity in New York City
It is well recognized that an interdisciplinary approach is essential in the development and implementation of solutions to address the current pediatric obesity epidemic. In two half-day meetings that included workshops and focus groups, faculty from diverse fields identified critically important research challenges, and gaps to childhood obesity prevention. The purpose of this white paper is to describe the iterative, interdisciplinary process that unfolded in an academic health center setting with a specific focus on underrepresented minority groups of Black and Hispanic communities, and to summarize the research challenges and gaps related to pediatric obesity that were identified in the process. Although the research challenges and gaps were developed in the context of an urban setting including high-risk populations (the northern Manhattan communities of Washington Heights, Inwood, and Harlem), many of the issues raised are broadly applicable. The processes by which the group identified research gaps and methodological challenges that impede a better understanding of how to prevent and treat obesity in children has resulted in an increase in research and community outreach collaborations and interdisciplinary pursuit of funding opportunities across units within the academic health center and overall university.
Early depressed mood after stroke predicts long-term disability: the Northern Manhattan Stroke Study (NOMASS)
BACKGROUND AND PURPOSE: Depression is highly prevalent after stroke and may influence recovery. We aimed to determine whether depressed mood acutely after stroke predicts subsequent disability and mortality. METHODS: As part of the Northern Manhattan Stroke Study, a population-based incident stroke case follow-up study performed in a multiethnic urban population, participants were asked about depressed mood within 7 to 10 days after stroke. Participants were followed every 6 months the first 2 years and yearly thereafter for 5 years for death and disability measured by the Barthel Index. We fitted polytomous logistic regression models using a canonical link to examine the association between depressed mood after stroke and disability comparing moderate (Barthel Index 60 to 95) and severe (Barthel Index <60) disability with no disability (Barthel Index >or=95). Cox proportional hazards models were created to examine the association between depressed mood and mortality. RESULTS: A question about depressed mood within 7 to 10 days after stroke was asked in 340 of 655 patients with ischemic stroke enrolled, and 139 reported that they felt depressed. In multivariate analyses controlling for sociodemographic factors, stroke severity, and medical conditions, depressed mood was associated with a greater odds of severe disability compared with no disability at 1 (OR 2.91, 95% CI 1.07 to 7.91) and 2 years (OR 3.72, 95% CI 1.29 to 10.71) after stroke. Depressed mood was not associated with all-cause mortality or vascular death. CONCLUSIONS: Depressed mood after stroke is associated with disability but not mortality after stroke. Early screening and intervention for mood disorders after stroke may improve outcomes and requires further research.
Increased stroke risk and lipoprotein(a) in a multiethnic community: the Northern Manhattan Stroke Study
CONTEXT: Elevated lipoprotein(a) [Lp(a)] is associated with ischemic stroke (IS) among Whites, but data is sparse for non-White populations. OBJECTIVE: Using a population-based case-control study design with subjects from the Northern Manhattan Stroke Study, we assessed whether Lp(a) levels were independently associated with IS risk among Whites, Blacks and Hispanics. DESIGN AND SETTING: Lp(a) levels were measured in 317 IS cases (mean age 69 +/- 13 years; 56% women; 16% Whites, 31% Blacks and 52% Hispanics) and 413 community-based controls, matched by age, race/ethnicity and gender. In-person assessments included demographics, socioeconomic status, presence of vascular risk factors and fasting lipid levels. Logistic regression was used to determine the independent association of Lp(a) and IS. Stratified analyses investigated gender and race/ethnic differences. RESULTS: Mean Lp(a) levels were greater among cases than controls (46.3 +/- 41.0 vs. 38.9 +/- 38.2 mg/dl; p < 0.01). After adjusting for stroke risk factors (hypertension, diabetes mellitus, coronary artery disease, cigarette smoking), lipid levels, and socioeconomic status, Lp(a) levels > or =30 mg/dl were independently associated with an increased stroke risk in the overall cohort (adjusted odds ratio, OR, 1.8, 95% confidence interval, CI, 1.20-2.6; p = 0.004). There was a significant linear dose-response relationship between Lp(a) levels and IS risk. The association between IS risk and Lp(a) > or =30 mg/dl was more pronounced among men (adjusted OR 2.0, 95% CI 1.1-3.5; p = 0.02) and among Blacks (adjusted OR 2.7, 95% CI 1.2-6.2; p = 0.02). CONCLUSION: Elevated Lp(a) levels were significantly and independently associated with increased stroke risk, suggesting that Lp(a) is a risk factor for IS across White, Black and Hispanic race/ethnic groups.
Snoring and insomnia are not associated with subclinical atherosclerosis in the Northern Manhattan Study
BACKGROUND: Sleep-disordered breathing is a risk factor for stroke, but its association with subclinical atherosclerosis remains controversial. Snoring and insomnia are frequently comorbid with sleep-disordered breathing and may contribute to stroke. Data on the relationship between snoring and insomnia with atherosclerotic disease are sparse. We investigated the relationship between markers of subclinical atherosclerosis, insomnia, snoring, and carotid intima-media thickness, in the Northern Manhattan Study. METHODS: A group of 1605 participants (mean age 65 +/- 8 years; 40% men; 61% Hispanic, 19% black, 20% white) who had carotid intima-media thickness measurements performed was assessed for self-reported sleep habits. Habitual snoring was defined as self-reported snoring greater than four times per week. Presence of insomnia was based on three items extracted from the Hamilton Rating Scale for Depression. Carotid intima-media thickness was expressed as a mean composite measure of intima-media thickness in the carotid bifurcation, common, and internal carotid artery. Multivariate linear regression models were used to identify associations between snoring, insomnia, and carotid intima-media thickness. RESULTS: Habitual snoring was present in 29% of the subjects and insomnia in 26%. There was a higher prevalence of self-reported snoring (84%) and insomnia (66%) among Hispanics than non-Hispanics. The mean total carotid intima-media thickness was 0.95 +/- 0.09 mm; among those with self-reported snoring was 0.94 +/- 0.09 mm; and among those with insomnia was 0.95 +/- 0.08 mm. After controlling for age, gender, race-ethnicity, body mass index and cardiovascular risk factors, snoring (P=0.986) and insomnia (P=0.829) were not significantly associated with increased carotid intima-media thickness. CONCLUSION: Snoring and insomnia were not significantly associated with subclinical atherosclerosis in this population-based community cohort.
Social determinants of physical inactivity in the Northern Manhattan Study (NOMAS)
Physical inactivity is an important and modifiable cardiovascular disease risk factor. Little is known about the social determinants of physical inactivity in older, urban-dwelling populations. We collected socio-demographic and medical risk factor information and physical activity questionnaires in the Northern Manhattan Study. Logistic regression models were constructed to examine whether measures of social isolation, race-ethnicity, and sex were associated with physical inactivity. Physical inactivity was present in 40.5% of the cohort. In multivariable models adjusted for medical comorbidities, Hispanic race-ethnicity (compared to non-Hispanic white) was associated with higher odds of physical inactivity (OR 2.18, 95% CI 1.78, 2.67), while women were more likely to be inactive than men (OR 1.33, 95% CI 1.15, 1.54). Having Medicaid/being uninsured (OR 1.20, 95% CI 1.02, 1.42), and having fewer than 3 friends (1.41, 95% CI 1.15, 1.72) were also associated with physical inactivity. Physical inactivity is common, particularly in Hispanics, women, and those who are socially isolated. Public health interventions aimed at increasing physical activity in these more sedentary groups are required.
Quality of life declines after first ischemic stroke. The Northern Manhattan Study
OBJECTIVES: Quality of life (QOL) after stroke is poorly characterized. We sought to determine long-term natural history and predictors of QOL among first ischemic stroke survivors without stroke recurrence or myocardial infarction (MI). METHODS: In the population-based, multiethnic Northern Manhattan Study, QOL was prospectively assessed at 6 months and annually for 5 years using the Spitzer QOL index (QLI), a 10-point scale. Functional status was assessed using the Barthel Index (BI) at regular intervals, and cognition using the Mini-Mental State Examination at 1 year. Generalized estimating equations estimated the association between patient characteristics and repeated QOL measures over 5 years. Follow-up was censored at death, recurrent stroke, or MI. RESULTS: There were 525 incident ischemic stroke patients >/=40 years (mean age 68.6 +/- 12.4 years). QLI declined after stroke (annual change -0.10, 95% confidence interval -0.17 to -0.04), after adjusting for age, sex, race-ethnicity, education, insurance, depressed mood, stroke severity, bladder continence, and stroke laterality. This decline remained when BI >/=95 was added to the model as a time-dependent covariate, and functional status also predicted QLI. Changes in QLI over time differed by insurance status (p for interaction = 0.0017), with a decline for those with Medicaid/no insurance (p < 0.0001) but not Medicare/private insurance (p = 0.98). CONCLUSIONS: In this population-based study, QOL declined annually up to 5 years after stroke among survivors free of recurrence or MI and independently of other risk factors. QLI declined more among Medicaid patients and was associated with age, mood, stroke severity, urinary incontinence, functional status, cognition, and stroke laterality.
Metabolic syndrome increases carotid artery stiffness: the Northern Manhattan Study
BACKGROUND: Arterial stiffness, an intermediate pre-clinical marker of atherosclerosis, has been associated with an increased risk of stroke and cardiovascular disease. The metabolic syndrome and its components are established cardiovascular disease risk factors and may also increase arterial stiffness; however, data regarding this are limited. AIM: The goal of this study was to determine the association between the metabolic syndrome and carotid artery stiffness in an elderly multi-ethnic cohort. METHODS: Carotid artery stiffness was assessed by carotid ultrasound as part of the Northern Manhattan Study, a prospective population-based cohort of stroke-free individuals. Carotid artery stiffness was calculated as [ln(systolic BP/diastolic BP)/strain], where strain was [(systolic diameter-diastolic diameter)/diastolic diameter]. Metabolic syndrome was defined by the National Cholesterol Education Program: Adult Treatment Panel III criteria. LogSTIFF was analysed as the dependent variable in linear regression models, adjusting for demographics, education, current smoking, presence of carotid plaque and intima-media thickness. RESULTS: Carotid artery stiffness was analysed in 1133 Northern Manhattan Study subjects (mean age 65 +/- 9 years; 61% women; 58% Hispanic, 22% Black and 20% Caucasian). The prevalence of the metabolic syndrome was 49%. The mean LogSTIFF was 2.01 +/- 0.61 among those with the metabolic syndrome and 1.90 +/- 0.59 among those without the metabolic syndrome (P=0.003). The metabolic syndrome was significantly associated with increased logSTIFF in the final adjusted model (parameter estimate beta=0.100, P=0.01). Among individual metabolic syndrome components, waist circumference and elevated blood pressure were most significantly associated with a mean increase in logSTIFF (P<0.01). CONCLUSION: The metabolic syndrome is significantly associated with increased carotid artery stiffness in a multiethnic population. Increased carotid artery stiffness may, in part, explain a high risk of stroke among individuals with the metabolic syndrome.
Metabolic syndrome and cerebral vasomotor reactivity
BACKGROUND AND PURPOSE: Metabolic syndrome has been proposed as a risk factor for stroke and transient ischaemic attack. One pathophysiological mechanism could be impairment of endothelial function. Thus, we hypothesized that cerebral vasomotor reactivity would be decreased in patients with metabolic syndrome, compared to patients without metabolic syndrome. METHODS: In this retrospective analysis, 83 consecutive patients (aged 59.19 +/- 15.98; 33 women) underwent Doppler examination for carotid artery disease including bi-hemispherical vasomotor reactivity assessment using transcranial Doppler monitoring. Vasomotor reactivity data were analyzed from the hemisphere with no or low-grade carotid stenosis (<40%). Cerebral vasomotor reactivity was calculated as percent increase in mean flow velocity per mmHg pCO(2) during 2 min of 5% CO(2) inhalation delivered by anesthesia mask (normal if >/= 2%/mmHg). Univariate and multivariable linear regression models were used to determine factors, including metabolic syndrome, that were independently associated with pathologic vasomotor reactivity. RESULTS: After adjusting for the presence of contralateral carotid stenosis and ipsilateral stroke in the multivariable model, metabolic syndrome was independently associated with lower vasomotor reactivity values (2.27 +/- 1.24% vs. 2.68 +/- 1.37; ss = -0.258, P = 0.033). In this model, there was no association of cerebral vasomotor reactivity with age, gender, race, cardiac disease, current statin therapy, or small vessel disease. CONCLUSIONS: Our findings suggest that impaired cerebral vasomotor reactivity may be a mediator of stroke in patients with metabolic syndrome, a syndrome affecting a significant and growing proportion of the population. A prospective longitudinal study is warranted to study the cerebral haemodynamic effect of metabolic syndrome.
Genetic linkage of serum homocysteine in Dominican families: the Family Study of Stroke Risk and Carotid Atherosclerosis
BACKGROUND AND PURPOSE: Homocysteine levels are determined by genetic and environmental factors. Several studies have linked high plasma levels of total homocysteine to the increased risk of cardiovascular disease, stroke, and many other conditions. However, the exact mechanism of documented and novel total homocysteine quantitative trait loci to that risk is unknown. METHODS: We have performed linkage analysis in 100 high-risk Dominican families with 1362 members. Probands were selected from the population-based Northern Manhattan Study. A set of 405 microsatellite markers was used to screen the whole genome. Variance components analysis was used to detect evidence for linkage after adjusting for stroke risk factors. Ordered-subset analysis based on Dominican Republic enrollment was conducted. RESULTS: Total homocysteine levels had a heritability of 0.44 (P<0.0001). The most significant evidence for linkage was found at chromosome 17q24 (maximum logarithm of odds [MLOD]=2.66, P=0.0005) with a peak at D17S2193 and was significantly increased in a subset of families with a high proportion of Dominican Republic enrollment (MLOD=3.92, P=0.0022). Additionally, modest evidence for linkage was found at chromosome 2p21 (MLOD=1.77, P=0.0033) with a peak at D2S1356 and was significantly increased in a subset of families with a low proportion of Dominican Republic enrollment (MLOD=2.82, P=0.0097). CONCLUSIONS: We found a strong evidence for novel quantitative trait loci on chromosomes 2 and 17 for total homocysteine plasma levels in Dominican families. Our family study provides essential data for a better understanding of the genetic mechanisms associated with elevated total homocysteine levels leading to cardiovascular disease after accounting for environmental risk factors.
Periodontal bacteria and hypertension: the oral infections and vascular disease epidemiology study (INVEST)
OBJECTIVE: Chronic infections, including periodontal infections, may predispose to cardiovascular disease. We investigated the relationship between periodontal microbiota and hypertension. METHODS AND RESULTS: Six hundred and fifty-three dentate men and women with no history of stroke or myocardial infarction were enrolled in INVEST. We collected 4533 subgingival plaque samples (average of seven samples per participant). These were quantitatively assessed for 11 periodontal bacteria using DNA-DNA checkerboard hybridization. Cardiovascular risk factor measurements were obtained. Blood pressure and hypertension (SBP > or =140 mmHg, DBP > or =90 mmHg or taking antihypertensive medication, or self-reported history) were each regressed on the level of bacteria: considered causative of periodontal disease (etiologic bacterial burden); associated with periodontal disease (putative bacterial burden); and associated with periodontal health (health-associated bacterial burden). All analyses were adjusted for age, race/ethnicity, sex, education, BMI, smoking, diabetes, low-density lipoprotein and high-density lipoprotein cholesterol. Etiologic bacterial burden was positively associated with both blood pressure and prevalent hypertension. Comparing the highest and lowest tertiles of etiologic bacterial burden, SBP was 9 mmHg higher, DBP was 5 mmHg higher (P for linear trend was less than 0.001 in each case), and the odds ratio for prevalent hypertension was 3.05 (95% confidence interval 1.60-5.82) after multivariable adjustment. CONCLUSION: Our data provide evidence of a direct relationship between the levels of subgingival periodontal bacteria and both SBP and DBP as well as hypertension prevalence.
Impact of delayed transfer of critically ill stroke patients from the Emergency Department to the Neuro-ICU
BACKGROUND: We sought to determine the effect of emergency department length of stay (ED-LOS) on outcomes in stroke patients admitted to the Neurological Intensive Care Unit (NICU). METHODS: We collected data on all patients who presented to the ED at a single center from 1st February 2005 to 31st May 2007 with acute ischemic stroke (AIS), intracerebral hemorrhage (ICH), or transient ischemic attack (TIA) within 12 h of symptom onset. Data collected included demographics, admission/discharge National Institutes of Health Stroke Scale (NIHSS), discharge modified Rankin Score (mRS), and total ED length of stay. The effect of ED-LOS on discharge mRS, discharge NIHSS, and hospital LOS was assessed by logistic regression. Poor outcome was defined as mRS > or =4 at discharge. RESULTS: Of 519 patients presenting to the ED, 75 (15%) were critically ill and admitted to the NICU (mean age 65 +/- 14 years, 31% men, and 37% Hispanic). Admission diagnosis included AIS (49%), ICH (47%), TIA (1%), and others (3%). Median ED-LOS was 5 h (IQR 3-8 h) and median hospital LOS was 7 days (IQR 3-15 days). In multivariate analysis, predictors of poor outcome included admission ICH (OR, 2.1; 95% CI, 1.1-4.3), NIHSS > or =6 (OR, 6.4; 95% CI, 2.3-17.9), and ED-LOS > or =5 h (OR, 3.8; 95% CI, 1.6-8.8). There was no association between ED-LOS and discharge NIHSS among survivors or total hospital LOS. CONCLUSION: Among critically ill stroke patients, ED-LOS > or =5 h before transfer to the NICU is independently associated with poor outcome at hospital discharge.
Ethnic differences in aortic valve thickness and related clinical factors
BACKGROUND: Prior studies suggest that the causes of calcific aortic valve (AV) disease involve chronic inflammation, lipoprotein levels, and calcium metabolism, all of which may differ among race-ethnic groups. We sought to determine whether AV thickness differs by race-ethnicity in a large multiethnic population-based cohort. METHODS: The Northern Manhattan Study includes stroke-free community-based Hispanic (57%), non-Hispanic black (22%), and non-Hispanic white (21%) participants. The relation between AV thickness on transthoracic echocardiography and clinical risk factors for atherosclerosis was evaluated among 2,085 participants using polytomous logistic regression models. Aortic valve thickness was graded in 3 categories (normal, mild, and moderate/severe) based on leaflet thickening and calcification. RESULTS: Mild AV thickness was present in 44.4% and moderate/severe thickness in 5.7% of the cohort, with the lowest frequency of moderate/severe thickness seen particularly among Hispanic women. In multivariate models adjusting for age, sex, race-ethnicity, body mass index, hypertension, coronary artery disease, blood glucose, and high-density lipoprotein cholesterol, Hispanics had significantly less moderate/severe AV thickness (odds ratio 0.43, 95% CI 0.25-0.73) than non-Hispanic whites. Men were almost 2-fold as likely to have moderate/severe AV thickness compared with women (odds ratio 1.96, 95% CI 1.24-3.10). CONCLUSIONS: In this large multiethnic population-based cohort, there were ethnic differences in the degree of AV thickness. Hispanic ethnicity was strongly protective against AV thickness. This effect was not related to traditional risk factors, suggesting that unmeasured factors related to Hispanic ethnicity and AV thickness may be responsible.
A stroke preparedness RCT in a multi-ethnic cohort: design and methods
BACKGROUND: Tissue plasminogen activator (tPA), the only approved treatment for acute ischemic stroke (IS), is significantly underutilized likely due to poor lay information about stroke as an emergency. In order to improve outcomes in acute IS, it is critical to raise awareness and recognition of stroke symptoms particularly among minority populations. This manuscript describes the application of a stroke preparedness behavioral intervention and includes baseline information in a multi-ethnic population of stroke and transient ischemic attack (TIA) survivors. METHODS: In the Stroke Warning Information and Faster Treatment Study (SWIFT), we prospectively identified, and randomized IS and TIA patients to determine efficacy of a culturally tailored interactive stroke preparedness strategy. Data collected at baseline included acute stroke parameters, stroke knowledge, severity, social resources and vascular risk assessment. RESULTS: Of the 736 enrolled to date, 76% were IS and 24% TIA events. The cohort was 51% female: 45% Hispanic, 26% White and 25% Black. Over 75% reported hypertension, 36% diabetes, and 16% cardiac disease. Mean time from onset to emergency department (ED) arrival was 46h (median 13h) differing significantly between Whites (mean 52h, median 11h) and Blacks (mean 52h, median 17h) versus Hispanics (mean 39h, median 11h). Knowledge that a stroke occurs in the brain differed significantly by between Whites (85%), Blacks (64%), Hispanics (66%, p<0.000). CONCLUSIONS: Disparities remain in both action and knowledge surrounding acute stroke. Use of written information has not proven an effective means of changing health behaviors. We propose an interactive culturally tailored intervention to address behavioral change in acute stroke.
Endothelial function in individuals with coronary artery disease with and without type 2 diabetes mellitus
The goal of this study was to determine if individuals with coronary artery disease (CAD) and type 2 diabetes mellitus (T2DM) had greater endothelial dysfunction (ED) than individuals with only CAD. Flow-mediated dilation (FMD), calculated as percentage increase in brachial artery diameter in response to postischemic blood flow, was measured after an overnight fast in 2 cohorts. The first cohort included 76 participants in the Northern Manhattan Study with CAD; 25 also had T2DM. The second cohort was composed of 27 individuals with both T2DM and CAD who were participants in a study of postprandial lipemia. Combined, we analyzed 103 patients with CAD: 52 with T2DM (T2DM+) and 51 without T2DM (T2DM-). The 52 CAD T2DM+ subjects had a mean FMD of 3.9% +/- 3.2%, whereas the 51 CAD T2DM- subjects had a greater mean FMD of 5.5% +/- 4.0% (P < .03). An investigation of various confounders known to affect FMD identified age and body mass index as the only significant covariates in a multiple regression model. Adjusting for age and body mass index, we found that FMD remained lower in T2DM+ subjects compared with T2DM- subjects (difference, -1.99%; P < .03). In patients with CAD, the concomitant presence of T2DM is independently associated with greater ED, as measured by FMD. This finding may be relevant to the greater early and late morbidity and mortality observed in patients with both CAD and T2DM.
Infectious burden and carotid plaque thickness: the northern Manhattan study
BACKGROUND AND PURPOSE: The overall burden of prior infections may contribute to atherosclerosis and stroke risk. We hypothesized that serological evidence of common infections would be associated with carotid plaque thickness in a multiethnic cohort. METHODS: Antibody titers to 5 common infectious microorganisms (ie, Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus, and herpesvirus 1 and 2) were measured among stroke-free community participants and a weighted index of infectious burden was calculated based on Cox models previously derived for the association of each infection with stroke risk. High-resolution carotid duplex Doppler studies were used to assess maximum carotid plaque thickness. Weighted least squares regression was used to measure the association between infectious burden and maximum carotid plaque thickness after adjusting for other risk factors. RESULTS: Serological results for all 5 infectious organisms were available in 861 participants with maximum carotid plaque thickness measurements available (mean age, 67.2+/-9.6 years). Each individual infection was associated with stroke risk after adjusting for other risk factors. The infectious burden index (n=861) had a mean of 1.00+/-0.35 SD and a median of 1.08. Plaque was present in 52% of participants (mean, 0.90+/-1.04 mm). Infectious burden was associated with maximum carotid plaque thickness (adjusted increase in maximum carotid plaque thickness 0.09 mm; 95% CI, 0.03 to 0.15 mm per SD increase of infectious burden). CONCLUSIONS: A quantitative weighted index of infectious burden, derived from the magnitude of association of individual infections with stroke, was associated with carotid plaque thickness in this multiethnic cohort. These results lend support to the notion that past or chronic exposure to common infections, perhaps by exacerbating inflammation, contributes to atherosclerosis. Future studies are needed to confirm this hypothesis and to define optimal measures of infectious burden as a vascular risk factor.
Impaired flow-mediated vasodilatation is associated with increased left ventricular mass in a multiethnic population. The Northern Manhattan Study
BACKGROUND: Increased left ventricular (LV) mass and endothelial dysfunction are important risk factors for cardiovascular mortality and morbidity. However, it is not clear whether endothelial dysfunction is associated with increased LV mass. We tested the hypothesis that impaired flow-mediated vasodilatation (FMD) is associated with increased LV mass in a population-based multiethnic cohort. METHODS: As a part of the Northern Manhattan Study (NOMAS), we performed two-dimensional echocardiography and FMD assessment during reactive hyperemia by high-resolution ultrasonography in 867 stroke-free community participants. LV mass was calculated according to an established method. LV hypertrophy was defined as the 90th percentile of sex-specific LV mass indexed for body surface area among normal subjects. Multivariable models were used to test the association of FMD with LV mass. RESULTS: In multiple linear regression analysis adjusting for age, sex, body mass index, systolic blood pressure, antihypertensive medications, low-density lipoprotein cholesterol, diabetes, smoking, hematocrit, and race-ethnicity, FMD was inversely associated with LV mass (beta = -1.21 +/- 0.56, P = 0.03). The association persisted after further adjustment for any component of blood pressure (systolic, mean, and pulse pressure). In univariate logistic regression analysis, each 1% decrease in FMD was associated with an 8% higher risk of LV hypertrophy (odds ratio 1.08, 95% confidence interval 1.03-1.13 per each FMD point P < 0.01). CONCLUSIONS: Impaired FMD is associated with LV mass, independent of other factors associated with increased LV mass. Endothelial dysfunction might be a potential risk factor for LV hypertrophy.
Improving global vascular risk prediction with behavioral and anthropometric factors. The multiethnic NOMAS (Northern Manhattan Cohort Study)
OBJECTIVES: This study sought to improve global vascular risk prediction with behavioral and anthropometric factors. BACKGROUND: Few cardiovascular risk models are designed to predict the global vascular risk of myocardial infarction, stroke, or vascular death in multiethnic individuals, and existing schemes do not fully include behavioral risk factors. METHODS: A randomly derived, population-based, prospective cohort of 2,737 community participants free of stroke and coronary artery disease was followed up annually for a median of 9.0 years in the NOMAS (Northern Manhattan Study) (mean age 69 years, 63.2% women, 52.7% Hispanic, 24.9% African American, and 19.9% white). A global vascular risk score (GVRS) predictive of stroke, myocardial infarction, or vascular death was developed by adding variables to the traditional Framingham cardiovascular variables based on the likelihood ratio criteria. Model utility was assessed through receiver-operating characteristics, calibration, and effect on reclassification of subjects. RESULTS: Variables that significantly added to the traditional Framingham profile included waist circumference, alcohol consumption, and physical activity. Continuous measures for blood pressure and fasting blood sugar were used instead of hypertension and diabetes. Ten-year event-free probabilities were 0.95 for the first quartile of GVRS, 0.89 for the second quartile, 0.79 for the third quartile, and 0.56 for the fourth quartile. The addition of behavioral factors in our model improved prediction of 10-year event rates compared with a model restricted to the traditional variables. CONCLUSIONS: A GVRS that combines traditional, behavioral, and anthropometric risk factors; uses continuous variables for physiological parameters; and is applicable to nonwhite subjects could improve primary prevention strategies.
Birth and adult residence in the Stroke Belt independently predict stroke mortality
BACKGROUND: Understanding how the timing of exposure to the US Stroke Belt (SB) influences stroke risk may illuminate mechanisms underlying the SB phenomenon and factors influencing population stroke rates. METHODS: Stroke mortality rates for United States-born black and white people aged 30-80 years were calculated for 1980, 1990, and 2000 for strata defined by birth state, state of adult residence, race, sex, and birth year. Four SB exposure categories were defined: born in a SB state (North Carolina, South Carolina, Georgia, Tennessee, Arkansas, Mississippi, or Alabama) and lived in the SB at adulthood; non-SB born but SB adult residence; SB-born but adult residence outside the SB; and did not live in the SB at birth or in adulthood (reference group). We estimated age-, sex-, and race-adjusted odds ratios for stroke mortality associated with timing of SB exposure. RESULTS: Elevated stroke mortality was associated with both SB birth and, independently, SB adult residence, with the highest risk among those who lived in the SB at birth and adulthood. Compared to those living outside the SB at birth and adulthood, odds ratios for SB residence at birth and adulthood for black subjects were 1.55 (95% confidence interval 1.28, 1.88) in 1980, 1.47 (1.31, 1.65) in 1990, and 1.34 (1.22, 1.48) in 2000. Comparable odds ratios for white subjects were 1.45 (95% confidence interval 1.33, 1.58), 1.29 (1.21, 1.37), and 1.34 (1.25, 1.44). Patterns were similar for every race, sex, and age subgroup examined. CONCLUSION: Stroke Belt birth and adult residence appear to make independent contributions to stroke mortality risk.
Physical activity and risk of ischemic stroke in the Northern Manhattan Study
BACKGROUND: It is controversial whether physical activity is protective against first stroke among older persons. We sought to examine whether physical activity, as measured by intensity of exercise and energy expended, is protective against ischemic stroke. METHODS: The Northern Manhattan Study is a prospective cohort study in older, urban-dwelling, multiethnic, stroke-free individuals. Baseline measures of leisure-time physical activity were collected via in-person questionnaires. Cox proportional hazards models were constructed to examine whether energy expended and intensity of physical activity were associated with the risk of incident ischemic stroke. RESULTS: Physical inactivity was present in 40.5% of the cohort. Over a median follow-up of 9.1 years, there were 238 incident ischemic strokes. Moderate- to heavy-intensity physical activity was associated with a lower risk of ischemic stroke (adjusted hazard ratio [HR] 0.65, 95% confidence interval [0.44-0.98]). Engaging in any physical activity vs none (adjusted HR 1.16, 95% CI 0.88-1.51) and energy expended in kcal/wk (adjusted HR per 500-unit increase 1.01, 95% CI 0.99-1.03) were not associated with ischemic stroke risk. There was an interaction of sex with intensity of physical activity (p = 0.04), such that moderate to heavy activity was protective against ischemic stroke in men (adjusted HR 0.37, 95% CI 0.18-0.78), but not in women (adjusted HR 0.92, 95% CI 0.57-1.50). CONCLUSIONS: Moderate- to heavy-intensity physical activity, but not energy expended, is protective against risk of ischemic stroke independent of other stroke risk factors in men in our cohort. Engaging in moderate to heavy physical activities may be an important component of primary prevention strategies aimed at reducing stroke risk.
Lipid profile components and risk of ischemic stroke: the Northern Manhattan Study (NOMAS)
OBJECTIVE: To explore the relationship between lipid profile components and incident ischemic stroke in a stroke-free prospective cohort. DESIGN: Population-based prospective cohort study. SETTING: Northern Manhattan, New York. PATIENTS: Stroke-free community residents. Intervention As part of the Northern Manhattan Study, baseline fasting blood samples were collected on stroke-free community residents followed up for a mean of 7.5 years. MAIN OUTCOME MEASURES: Cox proportional hazard models were used to calculate hazard ratios and 95% confidence intervals for lipid profile components and ischemic stroke after adjusting for demographic and risk factors. In secondary analyses, we used repeated lipid measures over 5 years from a 10% sample of the population to calculate the change per year of each of the lipid parameters and to impute time-dependent lipid parameters for the full cohort. RESULTS: After excluding those with a history of myocardial infarction, 2940 participants were available for analysis. Baseline high-density lipoprotein cholesterol, triglyceride, and total cholesterol levels were not associated with risk of ischemic stroke. Low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol levels were associated with a paradoxical reduction in risk of stroke. There was an interaction with use of cholesterol-lowering medication on follow-up, such that LDL-C level was only associated with a reduction in stroke risk among those taking medications. An LDL-C level greater than 130 mg/dL as a time-dependent covariate showed an increased risk of ischemic stroke (adjusted hazard ratio, 3.81; 95% confidence interval, 1.53-9.51). CONCLUSIONS: Baseline lipid panel components were not associated with an increased stroke risk in this cohort. Treatment with cholesterol-lowering medications and changes in LDL-C level over time may have attenuated the risk in this population, and lipid measurements at several points may be a better marker of stroke risk.
Infectious burden and risk of stroke: the northern Manhattan study
OBJECTIVE: To determine the association between a composite measure of serological test results for common infections (Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus, and herpes simplex virus 1 and 2) and stroke risk in a prospective cohort study. DESIGN: Prospective cohort followed up longitudinally for median 8 years. SETTING: Northern Manhattan Study. Patients Randomly selected stroke-free participants from a multiethnic urban community. Main Outcome Measure Incident stroke and other vascular events. RESULTS: All 5 infectious serological results were available from baseline samples in 1625 participants (mean [SD] age, 68.4 [10.1] years; 64.9% women). Cox proportional hazards models were used to estimate associations of each positive serological test result with stroke. Individual parameter estimates were then combined into a weighted index of infectious burden and used to calculate hazard ratios and confidence intervals for association with risk of stroke and other outcomes, adjusted for risk factors. Each individual infection was positively, though not significantly, associated with stroke risk after adjusting for other risk factors. The infectious burden index was associated with an increased risk of all strokes (adjusted hazard ratio per standard deviation, 1.39; 95% confidence interval, 1.02-1.90) after adjusting for demographics and risk factors. Results were similar after excluding those with coronary disease (adjusted hazard ratio, 1.50; 95% confidence interval, 1.05-2.13) and adjusting for inflammatory biomarkers. CONCLUSIONS: A quantitative weighted index of infectious burden was associated with risk of first stroke in this cohort. Future studies are needed to confirm these findings and to further define optimal measures of infectious burden as a stroke risk factor.
Stroke literacy in Central Harlem: a high-risk stroke population
BACKGROUND: Awareness of stroke warning symptoms and risk factors (stroke literacy), as well as knowledge of available treatment options, may be poor in high-risk populations. We sought to evaluate stroke literacy among residents of Central Harlem, a predominantly African American population, in a cross-sectional study. METHODS: Ten community-based sites in Central Harlem were identified between 2005 and 2006 for administration of a stroke knowledge survey. Trained volunteers administered in-person closed-ended questionnaires focused on stroke symptoms and risk factors. RESULTS: A total of 1,023 respondents completed the survey. African Americans comprised 65.7% (n = 672) of the survey cohort. The brain was correctly identified as the site where a stroke occurs by 53.7% of respondents, whereas the heart was incorrectly identified by 20.8%. Chest pain was identified as a symptom of stroke by 39.7%. In multivariable analyses, African Americans (odds ratio [OR] 2.20, 95% confidence interval [CI] 1.09-4.45) and Hispanics (OR 5.27, 95% CI 2.46-11.30) were less likely to identify the brain as the damaged organ in stroke. Hispanics were more likely to incorrectly identify chest pain as a stroke symptom, compared with whites (OR 3.40, 95% CI 1.49-7.77). No associations were found between calling 911 and race/ethnicity and stroke knowledge, although women were more likely than men to call 911 (OR 0.50, 95% CI 0.30-0.80). CONCLUSION: Significant deficiencies in stroke literacy exist in this high-risk population, especially when compared with national means. Culturally tailored and sustainable educational campaigns should be tested in high-risk populations as part of stroke public health initiatives.
Long-term functional recovery after first ischemic stroke: the Northern Manhattan Study
BACKGROUND AND PURPOSE: Several factors predict functional status after stroke, but most studies have included hospitalized patients with limited follow-up. We hypothesized that patients with ischemic stroke experience functional decline over 5 years independent of recurrent stroke and other risk factors. METHODS: In the population-based Northern Manhattan Study, patients > or =40 years of age with incident ischemic stroke were prospectively followed using the Barthel Index at 6 months and annually to 5 years. Baseline stroke severity was categorized as mild (National Institutes of Health Stroke Scale <6), moderate (6 to 13), and severe (> or =14). Follow-up was censored at death, recurrent stroke, or myocardial infarction. Generalized Estimating Equations provided ORs and 95% CIs for predictors of favorable (Barthel Index > or =95) versus unfavorable (Barthel Index <95) functional status after adjusting for demographic and medical risk factors. RESULTS: Of 525 patients, mean age was 68.6+/-12.4 years, 45.5% were male, 54.7% Hispanic, 54.7% had Medicaid/no insurance, and 35.1% had moderate stroke. The proportion with Barthel Index > or =95 declined over time (OR, 0.91; 95% CI, 0.84 to 0.99). Changes in Barthel Index by insurance status were confirmed by a significant interaction term (beta for interaction=-0.167, P=0.034); those with Medicaid/no insurance declined (OR, 0.84; P=0.003), whereas those with Medicare/private insurance did not (OR, 0.99; P=0.92). CONCLUSIONS: The proportion of patients with functional independence after stroke declines annually for up to 5 years, and these effects are greatest for those with Medicaid or no health insurance. This decline is independent of age, stroke severity, and other predictors of functional decline and occurs even among those without recurrent stroke or myocardial infarction.
Incidence and risk factors of intracranial atherosclerotic stroke: the Northern Manhattan Stroke Study
BACKGROUND: To assess the prevalence of risk factors as determinants of intracranial atherosclerosis (IATH)-related stroke in a multi-ethnic community-based cohort. METHODS: The Northern Manhattan Stroke Study included a population-based incidence study and a nested case-control study. Incident cases of first ischemic stroke were 1:2 when matched to community controls by age, sex, and race/ethnicity. Vascular risk factors were assessed among controls and compared against the following stroke subtypes: IATH, extracranial atherosclerosis (EATH), and non-atherosclerotic (NATH: cardioembolic, lacunar, and cryptogenic). Conditional logistic-regression was used to determine the association between risk factors and stroke subtypes. RESULTS: The crude incidence of IATH was 8/100,000 per year and the relative incidence of IATH was higher than that of EATH in blacks (5.9 vs. 3.2/100,000 per year) and in Hispanics (5.0 vs. 1.7/100,000 per year). The IATH group had a higher prevalence of diabetes mellitus (DM; 67% IATH, 60% EATH, 48% NATH, and 23% controls; p < 0.05 IATH vs. control) and of metabolic syndrome (62% IATH, 40% EATH, 40% NATH, and 35% controls; p < 0.05 IATH vs. control). In multivariate analysis, DM conferred a higher risk for IATH versus NATH stroke (OR, 10.8; 95% CI, 2.0-57 vs. OR, 2.7; 95% CI, 1.9-3.9; p < 0.05) and much lower for EATH (OR, 6.2; 95% CI, 1.2-32). The metabolic syndrome conferred a higher risk for IATH stroke subtype (OR, 4.6; 95% CI, 1.1-18.7) when compared to EATH (OR, 2.3; CI, 0.6-9.1) and NATH (OR, 2.4; CI, 1.7-3.3). CONCLUSIONS: DM is a more important determinant for IATH-related stroke than EATH or NATH.
Soluble tumor necrosis factor receptor 1 level is associated with left ventricular hypertrophy: the northern Manhattan study
BACKGROUND: Although inflammatory markers may be associated with risk of cardiovascular events, few data are available regarding these markers and their association with left ventricular hypertrophy (LVH). We sought to evaluate whether inflammatory markers were independently associated with LVH in a multiethnic population in northern Manhattan. METHODS: A population-based cross-sectional study was conducted in 660 participants without stroke, who had undergone both transthoracic echocardiography and testing for soluble tumor necrosis factor receptor (sTNFR) 1, interleukin (IL)-6, and high-sensitivity C-reactive protein (hsCRP). LV mass was calculated according to an established formula. LVH was defined as LV mass >90th percentile of the participants. RESULTS: The mean age was 67.4 +/- 8.8 years, 35.5% were men, 61.7% were Hispanic, 19.7% were black, and 18.6% were white. In univariate analyses, hsCRP, IL-6, and sTNFR1 were significantly associated with LV mass. Multiple linear regression analyses demonstrated that sTNFR1 (P = 0.0008) was associated with LV mass after adjusting for demographic and medical risk factors, but hsCRP and IL-6 were not. When all markers were included in the same model, sTNFR1 remained significant, but hsCRP and IL-6 did not. Compared with the lowest quartile of sTNFR1, those in the highest quartile were more likely to have LVH (odds ratio = 1.84, 95% confidence interval, 0.97-3.64, P = 0.06). CONCLUSIONS: sTNFR1, but not hsCRP nor IL-6, is independently associated with increased LV mass. Chronic subclinical inflammation including the TNFR1-associated system may contribute to LVH.
Impact of mitral annular calcification on cardiovascular events in a multiethnic community: the Northern Manhattan Study
OBJECTIVES: We sought to determine the magnitude of the association between mitral annular calcification (MAC) and vascular events in a multiethnic cohort. BACKGROUND: Mitral annular calcification is common in the elderly and is associated with atherosclerotic risk factors. Its impact on the risk of cardiovascular events is controversial. METHODS: The study cohort consisted of 1,955 subjects, ages >or=40 years, and free of prior myocardial infarction (MI) and ischemic stroke (IS). Mitral annular calcification was assessed by transthoracic 2-dimensional echocardiography. The association between MAC and MI, IS, and vascular death (VD) was examined by Cox proportional hazard models with adjustment for established cardiovascular risk factors. The effect of MAC thickness was also analyzed. RESULTS: The mean age of the cohort was 68.0 +/- 9.7 years and the majority of subjects were Hispanics (56.8%). A total of 519 subjects (26.6%) had MAC. Of 498 patients with MAC thickness measurements available, 253 (13.1%) had mild to moderate MAC (1 to 4 mm) and 245 (12.7%) severe MAC (>4 mm). During a mean follow-up of 7.4 +/- 2.5 years, MI occurred in 100 (5.1%) subjects, IS in 104 (5.3%) subjects, and VD in 155 (8.0%) subjects. After adjustment for other cardiovascular risk factors, MAC was associated with an increased risk of MI (adjusted hazard ratio [HR]: 1.75; 95% confidence interval [CI]: 1.13 to 2.69, p = 0.011) and VD (adjusted HR: 1.53; 95% CI: 1.09 to 2.15, p = 0.015), but not IS (adjusted HR: 1.34; 95% CI: 0.87 to 2.05, p = 0.18). Further analysis revealed that the impact of MAC was related to its thickness, with MAC >4 mm being a strong and independent predictor of MI (adjusted HR: 1.89; 95% CI: 1.13 to 3.17, p = 0.008) and VD (adjusted HR: 1.81; 95% CI: 1.21 to 2.72, p = 0.002), and showing borderline association with IS (adjusted HR: 1.59; 95% CI: 0.95 to 2.67, p = 0.084). CONCLUSIONS: In this multiethnic cohort, MAC was a strong and independent predictor of cardiovascular events, especially MI and VD. The risk increase was directly related to MAC severity.
Consent administrator training to reduce disparities in research participation
PURPOSE: The aims for this paper are to summarize the current state of disparities in clinical research participation, discuss regulatory and interpersonal causes for these disparities, and to suggest an approach to address this problem by standardized training for consent administrators. ORGANIZING CONSTRUCT: A program based on the Precede-Proceed model for training consent administrators is proposed and described. CONCLUSIONS: The current process for informed consent for research is unstandardized and inadequate, and may contribute to racial and ethnic disparities. Researchers are urged to consider a formal training program for members of their research teams who will be obtaining participants' consent. CLINICAL RELEVANCE: An educational program for consent administrators may help to reduce disparities in research participation by improving communication between research staff and potential participants.
Dietary total fat intake and ischemic stroke risk: the Northern Manhattan Study
BACKGROUND: Dietary fat intake is associated with coronary heart disease risk, but the relationship between fat intake and ischemic stroke risk remains unclear. We hypothesized that total dietary fat as part of a Western diet is associated with increased risk of ischemic stroke. METHODS: As part of the prospective Northern Manhattan Study, 3,183 stroke-free community residents over 40 years of age underwent evaluation of their medical history and had their diet assessed by a food-frequency survey. Cox proportional hazard models calculated risk of incident ischemic stroke. RESULTS: The mean age of participants was 69 years, 63% were women, 21% were white, 24% black and 52% Hispanic. During a mean of 5.5 years of follow-up, 142 ischemic strokes occurred. After adjusting for potential confounders, risk of ischemic stroke was higher in the upper quintile of total fat intake compared to the lowest quintile (HR 1.6, 95% CI 1.0-2.7). Total fat intake >65 g was associated with increased risk of ischemic stroke (HR 1.6, 95% CI 1.2-2.3). Risk was attenuated after controlling for caloric intake. CONCLUSIONS: The results suggest that increased daily total fat intake, especially above 65 g, significantly increases risk of ischemic stroke.
Moderate alcohol consumption is associated with better endothelial function: a cross sectional study
BACKGROUND: Moderate alcohol consumption is protective against coronary artery disease. Endothelial dysfunction contributes to atherosclerosis and the pathogenesis of cardiovascular disease. The effects of alcohol consumption on endothelial function may be relevant to these cardiovascular outcomes, but very few studies have examined the effect of alcohol consumption on endothelial function assessed by flow-mediated dilation (FMD) of the brachial artery in humans. METHODS: In the population-based Northern Manhattan Study (NOMAS), we performed a cross-sectional analysis of lifetime alcohol intake and brachial artery FMD during reactive hyperemia using high-resolution B-mode ultrasound images among 884 stroke-free participants (mean age 66.8 years, women 56.6%, Hispanic 67.4%, black 17.4%, and white 15.2%). RESULTS: The mean brachial FMD was 5.7% and the median was 5.5%. Compared to non-drinkers, those who drank >1 drink/month to 2 drinks/day were more likely to have FMD above the median FMD (5.5%) (unadjusted OR 1.7, 95% CI 1.2-2.4, p = 0.005). In multivariate analysis, the relationship between moderate alcohol consumption and FMD remained significant after adjusting for multiple traditional cardiovascular risk factors, including sex, race-ethnicity, body mass index, diabetes mellitus, coronary artery disease, Framingham risk score, medication use (adjusted OR 1.8, 95%CI 1.1-3.0, p = 0.03). No beneficial effect on FMD was seen for those who drank more than 2 drinks/day. CONCLUSION: In conclusion, consumption of up to 2 alcoholic beverages per day was independently associated with better FMD compared to no alcohol consumption in this multiethnic population. This effect on FMD may represent an important mechanism in explaining the protective effect of alcohol intake on cardiovascular disease.
Physical activity participation among Caribbean Hispanic women living in New York: relation to education, income, and age
BACKGROUND: Inadequate participation in physical activity is a serious public health issue in the United States, with significant disparities among population groups. In particular, there is a scarcity of information about physical activity among Caribbean Hispanics, a group on the rise. METHODS: Our goal was to accumulate data on physical activity among Caribbean Hispanic women living in New York and determine the relation between physical activity and age, marital status, education, income, primary language, and children in the household. To this end, a survey adapted from the National Health Interview Survey of the National Center for Health Statistics assessing type, frequency, and duration of physical activity was administered. RESULTS: There were 318 self-identified Hispanic women who participated. Total activity time, mean 385 +/- 26 minutes, and education (r = 0.14, p < 0.01) were significantly related. Women who had attended some college had greater total activity time than those with some high school education (p = 0.046) or < 8th grade education (p = 0.022). Walking as a form of transportation was the most frequent pursuit, 285 +/- 21 minutes. Age (r = -0.34, p < 0.001) and education (r = 0.25, p < 0.001) correlated with nonwalking activity time (leisure time). Nonwalking activity times were greater in younger, that is, 18-29 years (p < 0.001) and college-educated women (p < 0.001). Physical activity recommendations were met by 11%; and 17% reported no physical activity. CONCLUSIONS: Among Caribbean Hispanic women living in New York City, the current recommendations for physical activity are met by 11%, and physical activity and education are significantly related. Our observation that education is a critical factor related to physical activity suggests that programs to address the promotion of a physically active lifestyle are needed.
Carotid bruit for detection of hemodynamically significant carotid stenosis: the Northern Manhattan Study
OBJECTIVE: The prevalence of carotid bruits and the utility of auscultation for predicting carotid stenosis are not well known. We aimed to establish the prevalence of carotid bruits and the diagnostic accuracy of auscultation for detection of hemodynamically significant carotid stenosis, using carotid duplex as the gold standard. METHODS: The Northern Manhattan Study (NOMAS) is a prospective multiethnic community-based cohort designed to examine the incidence of stroke and other vascular events and the association between various vascular risk factors and subclinical atherosclerosis. Of the stroke-free cohort (n=3298), 686 were examined for carotid bruits and underwent carotid duplex. Main outcome measures included prevalence of carotid bruits and sensitivity, specificity, positive predictive value, negative predictive value and accuracy of auscultation for prediction of ipsilateral carotid stenosis. RESULTS: Among 686 subjects with a mean age of 68.2 +/- 9.4 years, the prevalence of >/=60% carotid stenosis as detected by ultrasound was 2.2% and the prevalence of carotid bruits was 4.1%. For detection of carotid stenosis, sensitivity of auscultation was 56%, specificity was 98%, positive predictive value was 25%, negative predictive value was 99% and overall accuracy was 97.5%. DISCUSSION: In this ethnically diverse cohort, the prevalence of carotid bruits and hemodynamically significant carotid stenosis was low. Sensitivity and positive predictive value were also low, and the 44% false-negative rate suggests that auscultation is not sufficient to exclude carotid stenosis. While the presence of a bruit may still warrant further evaluation with carotid duplex, ultrasonography may be considered in high-risk asymptomatic patients, irrespective of findings on auscultation.
Metabolic syndrome, endothelial dysfunction, and risk of cardiovascular events: the Northern Manhattan Study (NOMAS)
BACKGROUND: Metabolic syndrome (MetS) predisposes to cardiovascular disease. Endothelial dysfunction is thought to be an important factor in the pathogenesis of atherosclerosis. We tested the hypothesis that both MetS and endothelial dysfunction are vascular risk factors and provide additive prognostic values in predicting cardiovascular events in a multiethnic community sample. METHODS: The study population consisted of 819 subjects (467 female, mean age 66.5 +/- 8.8 years, 66% Hispanic) enrolled in the NOMAS. Metabolic syndrome was defined using the revised Adult Treatment Panel III criteria. Brachial artery flow-mediated dilation (FMD) was measured using high-resolution ultrasound. Endothelial dysfunction was defined as FMD <8.44% (lower 3 quartiles). Cox proportional hazards models were used to assess the effect of MetS and endothelial dysfunction on risk of cardiovascular events. RESULTS: During 81 +/- 21 months of follow-up, events occurred in 84 subjects. Metabolic syndrome was independently associated with cardiovascular events in a multivariate model, including cardiovascular risk factors (adjusted hazard ratio 2.08, 95% CI 1.27-3.40). Subjects with both MetS and endothelial dysfunction were at higher risk for cardiovascular events than those with either one of them alone (adjusted hazard ratio 2.60, 95% CI 1.14-5.92). CONCLUSIONS: Metabolic syndrome is associated with incident cardiovascular events. Combined use of MetS and FMD identifies those who are at higher risk of cardiovascular events. Metabolic syndrome and noninvasive FMD testing can be used concurrently for cardiovascular risk prediction.
Stroke location and association with fatal cardiac outcomes: Northern Manhattan Study (NOMAS)
BACKGROUND AND PURPOSE: Cardiac mortality after stroke is common, and small studies have suggested an association of short-term cardiac mortality with insular location of cerebral infarction. Few population-based studies with long-term follow-up have evaluated the effect of stroke location on the long-term risk of cardiac death or myocardial infarction (MI) after first ischemic stroke. We sought to determine the association between stroke location and cardiac death or MI in a multiethnic community-based cohort. METHODS: The Northern Manhattan Study is a population-based study designed to determine stroke incidence, risk factors, and prognosis in a multiethnic urban population. First ischemic stroke patients age 40 or older were prospectively followed up for cardiac death defined as fatal MI, fatal congestive heart failure, or sudden death/arrhythmia and for nonfatal MI. Primary brain anatomic site was determined by consensus of research neurologists. Hazard ratios (HRs) and 95% CIs were calculated by Cox proportional-hazards models and adjusted for vascular risk factors (age, sex, history of coronary disease, hypertension, diabetes, cholesterol, and smoking), stroke severity, infarct size, and stroke etiology. RESULTS: The study population consisted of 655 patients whose mean age was 69.7+/-12.7 years; 44.6% were men and 51.3% were Hispanic. During a median follow-up of 4.0 years, 44 patients (6.7%) had fatal cardiac events. Of these, fatal MI occurred in 38.6%, fatal congestive heart failure in 18.2%, and sudden death in 43.2%. In multivariate models, clinical diagnosis of left parietal lobe infarction was associated with cardiac death (adjusted HR=4.45; 95% CI, 1.83 to 10.83) and cardiac death or MI (adjusted HR=3.30; 95% CI, 1.45 to 7.51). When analysis of anatomic location was restricted to neuroimaging (computed tomography, magnetic resonance imaging, or both [n=447]), left parietal lobe infarction was associated with cardiac death (adjusted HR=3.37; 95% CI, 1.26 to 8.97), and both left (adjusted HR=3.49; 95% CI, 1.38 to 8.80) and right (adjusted HR=3.13; 95% CI, 1.04 to 9.45) parietal lobe infarctions were associated with cardiac death or MI. We did not find an association between frontal, temporal, or insular stroke and fatal cardiac events, although the number of purely insular strokes was small. CONCLUSIONS: Parietal lobe infarction is an independent predictor of long-term cardiac death or MI in this population. Further studies are needed to confirm whether parietal lobe infarction is an independent predictor of cardiac events and death. Surveillance for cardiac disease and implementation of cardioprotective therapies may reduce cardiac mortality in patients with parietal stroke.
The association between kidney disease and cardiovascular risk in a multiethnic cohort: findings from the Northern Manhattan Study (NOMAS)
BACKGROUND AND PURPOSE: The objective of this study was to determine the relationship between chronic kidney disease (CKD), race-ethnicity, and vascular outcomes. METHODS: A prospective, multiracial cohort of 3298 stroke-free subjects with 6.5 years of mean follow-up time for vascular outcomes (stroke, myocardial infarction, vascular death) was used. Kidney function was estimated using serum creatinine and Cockcroft-Gault formula. Cox proportional hazards models were fitted to evaluate the relationship between kidney function and vascular outcomes. RESULTS: In multivariate analysis, Cockcroft-Gault formula between 15 and 59 mL/min was associated with a significant 43% increased stroke risk in the overall cohort. Blacks with Cockcroft-Gault formula between 15 and 59 mL/min had significantly increased risk of both stroke (hazard ratio, 2.65; 95% CI, 1.47 to 4.77) and combined vascular outcomes (hazard ratio, 1.59; 95% CI, 1.10-2.92). CONCLUSIONS: Chronic kidney disease is a significant risk factor for stroke and combined vascular events, especially in blacks.
Self-reported peripheral arterial disease predicts future vascular events in a community-based cohort
BACKGROUND: Lower extremity peripheral arterial disease (PAD) is highly prevalent and strongly associated with cardiovascular morbidity and mortality. The ankle-brachial index used to screen for PAD is not routinely performed in primary care settings. OBJECTIVE: To determine if self-reported PAD is an independent predictor of combined vascular events (myocardial infarction, ischemic stroke, and vascular death). DESIGN: Ongoing population-based prospective cohort (the Northern Manhattan Study). Subjects enrolled between July 1993 and June 2001 with a mean follow-up time of 7.1 years. PATIENTS: Subjects (n = 2,977), aged 40 years or older and free of prior stroke or myocardial infarction, were classified as having self-reported PAD if they answered affirmatively to one of two questions regarding exercise-induced leg pain or a prior diagnosis of PAD. MAIN OUTCOME MEASURES: Combined vascular outcome defined as incident myocardial infarction, incident ischemic stroke, or vascular death. RESULTS: The mean age of the cohort was 68.9 +/- 10.4 years; 64% were women; 54% Hispanic, 25% African-American, 21% Caucasian; 15% reported having PAD. After a mean follow-up of 7.1 years, self-reported PAD was significantly predictive of combined events (n = 484) in the univariate model (HR 1.5, 95% CI, 1.2-1.9) and after adjustment for traditional cardiovascular risk factors (HR 1.3, 95% CI, 1.0-1.7). CONCLUSION: Self-reported PAD is an independent risk factor for future vascular events in this predominantly non-white cohort. The addition of two simple PAD questions to the routine medical history in general medicine settings could identify high-risk patients who would benefit from further vascular evaluation and risk factor modification.
Association between diabetes mellitus and left ventricular hypertrophy in a multiethnic population
It is still controversial whether type 2 diabetes mellitus (T2DM) is associated with increased left ventricular (LV) mass independent of body size. We tested the hypothesis that T2DM is independently associated with LV mass in a multiethnic cohort. In the Northern Manhattan Study (NOMAS) cohort sample, a total of 1,932 subjects (67.9+/-9.6 years, 769 men and 1,163 women, 443 with DM and 1,489 without DM) were studied by transthoracic echocardiography, and LV mass was calculated. LV hypertrophy was defined as the upper quartile of LV mass. Multivariable models were used to assess the association of T2DM with LV mass after adjusting for age, gender, race, body mass index (BMI), systolic blood pressure, education, history of coronary artery disease, physical activity, and alcohol consumption. LV mass (189+/-60 vs 174+/-59 g, p<0.0001), BMI, and systolic blood pressure were higher in the DM group than in the non-DM group, whereas age and gender distributions were similar between groups. In multivariable analysis, T2DM was independently associated with increased LV mass (p=0.03). Presence of T2DM was associated with increased risk of LV hypertrophy (adjusted odds ratio 1.46, 95% confidence interval 1.13 to 1.88, p=0.004). Although no interactions were observed between T2DM and BMI on LV hypertrophy (p=0.6), there was a significant interaction between T2DM and waist circumference on LV hypertrophy (p=0.01). In conclusion, T2DM was independently associated with increased LV hypertrophy independent of various covariates in this multiethnic sample. Presence of T2DM increased the risk of LV hypertrophy by about 1.5-fold, and it possibly interacted with central obesity.
Carotid plaque, a subclinical precursor of vascular events: the Northern Manhattan Study
BACKGROUND: Carotid atherosclerosis is a known biomarker associated with future vascular disease. The risk associated with small, nonstenotic carotid plaques is less clear. The objective of this study was to examine the association between maximum carotid plaque thickness and risk of vascular events in an urban multiethnic cohort. METHODS: As part of the population-based Northern Manhattan Study, carotid plaque was analyzed among 2,189 subjects. Maximum carotid plaque thickness was evaluated at the cutoff level of 1.9 mm, a prespecified value of the 75th percentile of the plaque thickness distribution. The primary outcome measure was combined vascular events (ischemic stroke, myocardial infarction, or vascular death). RESULTS: Carotid plaque was present in 1,263 (58%) subjects. After a mean follow-up of 6.9 years, vascular events occurred among 319 subjects; 121 had fatal or nonfatal ischemic stroke, 118 had fatal or nonfatal myocardial infarction, and 166 died of vascular causes. Subjects with maximum carotid plaque thickness greater than 1.9 mm had a 2.8-fold increased risk of combined vascular events in comparison to the subjects without carotid plaque (hazard ratio, 2.80; 95% CI, 2.04-3.84). In fully adjusted models, this association was significant only among Hispanics. Approximately 44% of the low-risk individuals by Framingham risk score had a 10-year vascular risk of 18.3% if having carotid plaque. CONCLUSIONS: Maximum carotid plaque thickness is a simple and noninvasive marker of subclinical atherosclerosis associated with increased risk of vascular outcomes in a multiethnic cohort. Maximum carotid plaque thickness may be a simple and nonexpensive tool to assist with vascular risk stratification in preventive strategies and a surrogate endpoint in clinical trials.
Diabetes, fasting glucose levels, and risk of ischemic stroke and vascular events: findings from the Northern Manhattan Study (NOMAS)
OBJECTIVE: There is insufficient randomized trial data to support evidence-based recommendations for tight control of fasting blood glucose (FBG) among diabetic subjects in primary stroke prevention. We explored the relationship between FBG among diabetic subjects and risk of ischemic stroke in a multiethnic prospective cohort. RESEARCH DESIGN AND METHODS: Medical and social data and FBG values were collected for 3,298 stroke-free community residents: mean age +/- SD was 69 +/-10 years; 63% were women, 21% were white, 24% were black, and 53% were Hispanic; and follow-up was 6.5 years. Baseline FBG levels were categorized: 1) elevated FBG: history of diabetes and FBG >or=126 mg/dl (7.0 mmol/l); 2) target FBG: history of diabetes and FBG <126 mg/dl (7.0 mmol/l); or 3) no diabetes/reference group. Cox models were used to calculate hazard ratios (HRs) and 95% CI for ischemic stroke and vascular events. RESULTS: In the Northern Manhattan Study, 572 participants reported a history of diabetes and 59% (n = 338) had elevated FBG. Elevated FBG among diabetic subjects was associated with female sex (P < 0.04), Medicaid (P = 0.01), or no insurance (P = 0.03). We detected 190 ischemic strokes and 585 vascular events. Diabetic subjects with elevated FBG (HR 2.7 [95% CI 2.0-3.8]) were at increased risk of stroke, but those with target FBG levels (1.2 [0.7-2.1]) were not, even after adjustment. A similar relationship existed for vascular events: elevated FBG (2.0 [1.6-2.5]) and target FBG (1.3 [0.9-1.8]. CONCLUSIONS: This prospective cohort study provides evidence for the benefits of tighter glucose control for primary stroke prevention.
Metabolic syndrome and ischemic stroke risk: Northern Manhattan Study
BACKGROUND AND PURPOSE: More than 47 million individuals in the United States meet the criteria for the metabolic syndrome. The relation between the metabolic syndrome and stroke risk in multiethnic populations has not been well characterized. METHODS: As part of the Northern Manhattan Study, 3298 stroke-free community residents were prospectively followed up for a mean of 6.4 years. The metabolic syndrome was defined according to guidelines established by the National Cholesterol Education Program Adult Treatment Panel III. Cox proportional-hazards models were used to calculate hazard ratios (HRs) and 95% CIs for ischemic stroke and vascular events (ischemic stroke, myocardial infarction, or vascular death). The etiologic fraction estimates the proportion of events attributable to the metabolic syndrome. RESULTS: More than 44% of the cohort had the metabolic syndrome (48% of women vs 38% of men, P<0.0001), which was more prevalent among Hispanics (50%) than whites (39%) or blacks (37%). The metabolic syndrome was associated with increased risk of stroke (HR=1.5; 95% CI, 1.1 to 2.2) and vascular events (HR=1.6; 95% CI, 1.3 to 2.0) after adjustment for sociodemographic and risk factors. The effect of the metabolic syndrome on stroke risk was greater among women (HR=2.0; 95% CI, 1.3 to 3.1) than men (HR=1.1; 95% CI, 0.6 to 1.9) and among Hispanics (HR=2.0; 95% CI, 1.2 to 3.4) compared with blacks and whites. The etiologic fraction estimates suggest that elimination of the metabolic syndrome would result in a 19% reduction in overall stroke, a 30% reduction of stroke in women; and a 35% reduction of stroke among Hispanics. CONCLUSIONS: The metabolic syndrome is an important risk factor for ischemic stroke, with differential effects by sex and race/ethnicity.
Effect of social support on nocturnal blood pressure dipping
OBJECTIVE: To determine if nocturnal blood pressure (BP) dipping among non-Hispanic blacks is influenced by social support. Non-Hispanic blacks have higher rates of cardiovascular morbidity and mortality from hypertension and are more likely to have ambulatory blood pressure (ABP) that remains high at night (nondipping). METHODS: A total of 68 non-Hispanic black normotensive and 13 untreated hypertensive participants (age 72 +/- 10 years, 48% female) free of clinical cardiovascular disease completed 24-hour ABP monitoring and a questionnaire that included a modified version of the CARDIA Study Social Support Scale (CSSS). Nondipping was defined as a decrease of <10% in the ratio between average awake and average asleep systolic BP. Analyses were adjusted for age, gender, and systolic BP. RESULTS: The prevalence of nondipping was 26.8% in subjects in the highest CSSS tertile versus 41.1% in the lowest CSSS tertile (p = .009). On adjusted analysis, CSSS was analyzed as a continuous variable and remained independently and inversely associated with nondipping (odds ratio 0.27, 95% Confidence Interval 0.08-0.94, p = .04). CONCLUSIONS: Social support may be an important predictor of BP dipping at night. These findings suggest that social support may have positive health affects through physiologic (autonomic) pathways.
Usefulness of fasting blood glucose to predict vascular outcomes among individuals without diabetes mellitus (from the Northern Manhattan Study)
It is still controversial whether fasting blood glucose (FBG) is associated with the risk of vascular outcomes among nondiabetic subjects. We sought to determine whether FBG is associated with vascular outcomes and whether this association differs among various racial or ethnic groups. In the Northern Manhattan Study, a total of 2,372 subjects (mean age 68.8 +/- 10.7 years, 36% men) without a history of diabetes mellitus, stroke, or myocardial infarction (MI) were followed for an average of 7.5 years for ischemic stroke, MI, and combined vascular events defined as either ischemic stroke, MI, or vascular death. Cox proportional-hazards models were used to calculate hazard ratios and 95% confidence intervals (CIs) of FBG-associated risk for vascular outcomes after adjusting for age, gender, race/ethnicity, education, body mass index, hypertension, current smoking, previous coronary artery disease, low-density lipoprotein cholesterol, alcohol intake, and physical activity. The incidences of MI, ischemic stroke, and combined vascular events were 5.5, 6.3, and 20.0 per 1,000 person-years, respectively. Each SD increase of FBG (27 mg/dl) was associated with statistically significantly increased risks of combined vascular events (hazard ratio 1.20, 95% CI 1.09 to 1.31) and MI (hazard ratio 1.21, 95% CI 1.02 to 1.44), but the effect was weaker, evident for ischemic stroke (hazard ratio 1.13, 95% CI 0.95 to 1.34). FBG was significantly associated with incident ischemic stroke among African-American subjects (hazard ratio 1.38, 95% CI 1.09 to 1.74) and incident MI among Hispanic subjects (hazard ratio 1.24, 95% CI 0.99 to 1.55). In conclusion, FBG was an independent predictor for vascular outcomes among individuals without history of diabetes from this multiethnic cohort. The effects were more apparent for MI than for ischemic stroke; however, FBG was a strong predictor of ischemic stroke among African-American subjects.
Leukocyte count predicts outcome after ischemic stroke: the Northern Manhattan Stroke Study
Leukocyte counts predict incident cardiovascular disease, but little data are available on the relationship of leukocyte count to outcome after ischemic stroke. We hypothesized that leukocyte count at the time of incident ischemic stroke is associated with prognosis. Patients with first ischemic stroke were prospectively followed for 5 years for the occurrence of recurrent stroke, myocardial infarction (MI), or death. Cox proportional hazard models were constructed to estimate hazard ratios and 95% confidence intervals (CIs) for the effect of leukocyte count on outcomes after adjusting for other risk factors. Ischemic stroke patients (n = 655) were evaluated (mean age, 69.7 +/- 12.7 years; 45% men; 51% Hispanic, 28% black, and 19% white). Seventy percent of samples were drawn within 24 hours of stroke. Mean leukocyte count was 9.1 +/- 4.7 x 10(9)/L. Leukocyte count was a significant independent predictor of the 30-day risk of recurrent stroke, MI, or death after adjusting for age, sex, race/ethnicity, other risk factors, and stroke severity (adjusted hazard ratio per unit increase in leukocyte count, 1.07; 95% CI, 1.00 to 1.13). Leukocyte count was also a significant independent predictor of outcome events over 5 years (adjusted hazard ratio per unit increase in leukocyte count, 1.04; 95% CI, 1.00 to 1.07). Our findings indicate that elevated leukocyte count at the time of ischemic stroke predicts future recurrent stroke, MI, or death. Acute infectious complications of stroke or underlying inflammation could account for this association.
Development and validation of a model to estimate stroke incidence in a population
Stroke is a common condition with a substantial impact on health care. Using published epidemiological data, a mathematical model was created to predict annual stroke incidence in populations over 45 years old, utilizing age, gender, ethnicity, and stroke risk factor prevalence (hypertension, atrial fibrillation, diabetes, smoking, and ischemic heart disease). The purpose of this study is to assess the models ability to reliably estimate the annual number of first strokes. The model was validated against two cohorts: the Northern Manhattan Stroke Study (NM), performed in 1995 and 1996, and the Copenhagen City Heart Study (CCHS), undertaken in 1980-84, 1984-88, and 1988-93. Both cohorts provided the actual number of first strokes for respective years and risk factor prevalence. The Mantel-Haenszel test compared actual to predicted incidence rates. The two cohorts differed in risk factor prevalences, size, and demographics. For all cohort groups/years, the predicted number of annual first strokes was not statistically different from actual first stroke incidence (P > .05). In NM, the actual number of first strokes compared to predicted was 7 versus 13 (P = .18) for 1995 and 9 versus 18 (P = .08) for 1996. Actual and predicted annual strokes in CCHS for the time frames 1980-83, 1984-88, and 1988-93 were 65 versus 69 (P = .73), 72 versus 87 (P = .23), and 75 versus 93 (P = .16), respectively. The model provides a tool for estimating annual first strokes within a population, with a tendency of bias toward overestimating the number of incident strokes. This evidence-based model may be utilized by health policy makers to predict stroke burden at a population level.
Association of education and race/ethnicity with physical activity in insured urban women
BACKGROUND: Physical inactivity is a growing problem facing American women. As little as 150 minutes of moderate physical activity (PA) weekly can reduce the risk of chronic diseases, such as heart disease and stroke. We developed a survey to determine levels and predictors of PA in a diverse population of urban women with access to healthcare. METHODS: From February to September 2004, women visiting an academic health center completed a self-administered PA survey. Total activity time (TAT) was calculated as the sum of all activity (walking, jogging or running, dancing, calisthenics, bicycling, aerobics, swimming) recorded over the preceding 2 weeks. Analysis of variance (ANOVA) models were used to assess the effect of different variables on TAT. RESULTS: The survey was completed by 242 women, mean age of 43.4 years. Ninety percent were insured; 66% were non-Hispanic white, 16% were Hispanic, and 10% were African American. Seventy-six percent of women were college graduates. Only 58% of participants recorded >or=150 minutes of PA/week. TAT was related to education, with a significant difference between high school and college graduates (290 +/- 80 vs. 502 +/- 40 min [SEM], p < 0.05). CONCLUSIONS: Education was strongly associated with TAT among these insured, diverse, and well-educated women. Only 58% exercised >or=150 minutes/week, underscoring the need to target exercise programs for all women and to close the gap between women of lower and higher educational attainment.
Use of thrombolysis in acute ischemic stroke: analysis of the Nationwide Inpatient Sample 1999 to 2004
STUDY OBJECTIVE: The aim of this study is to characterize hospital and patient characteristics associated with administration of thrombolysis in acute ischemic stroke patients in the United States. METHODS: This retrospective, observational, cohort study used data from the Nationwide Inpatient Sample, an administrative discharge database. A total of 366,194 hospitalizations admitted through the emergency department with a primary diagnosis of acute ischemic stroke were selected for analysis. The primary outcome considered in this study is whether the patient received thrombolytic therapy on hospital day 0 or 1. RESULTS: Thrombolysis was used in 1.12% (95% confidence interval [CI] 0.95% to 1.32%) of ischemic stroke hospitalizations. Most hospitals (69.5%; 95% CI 68.4% to 70.6%) treating ischemic stroke patients did not use thrombolysis during the study period. For the hospitals that used thrombolysis, the mean annual number of patients treated with thrombolysis per hospital was 3.06 (95% CI 2.68 to 3.44). In the binary logistic regression analysis, hospital characteristics associated with high use of thrombolysis were teaching hospital status and increasing number of stroke patients treated annually. Patient characteristics associated with higher use of thrombolysis were age younger than 55 years, male sex, and low comorbidity as measured by the modified Charlson Index; white race; and private self-pay health insurance. CONCLUSION: Use of thrombolysis for ischemic stroke in the United States from 1999 to 2004 was infrequent and showed significant differences, depending on hospital and patient demographic characteristics.
Genetic contribution to brachial artery flow-mediated dilation: the Northern Manhattan Family Study
BACKGROUND: Brachial artery flow-mediated dilation (FMD) is a non-invasive measure of endothelial function. Endothelial dysfunction has been associated with traditional vascular risk factors and increased risk of cardiovascular disease. The importance of genetic contribution to FMD and baseline brachial artery diameter has not been shown in Hispanic populations. The purpose of this study was to estimate the heritability of FMD. METHODS: Flow mediated dilation and brachial artery diameter were measured in a subset of Caribbean Hispanic families from the ongoing Northern Manhattan Family Study (NOMAFS), which studies the contribution of genetics to stroke and cardiovascular risk factors. The age- and sex-adjusted heritability of FMD was estimated using variance component methods. RESULTS: The current data include 620 subjects (97 probands and 523 relatives) from 97 families. The age and sex-adjusted heritability of brachial artery diameter was 0.57 (p<0.01). The age- and sex-adjusted heritability of FMD was 0.20 (p=0.01). After additional adjustment for systolic and diastolic blood pressure, body mass index, smoking, lipid, diabetes mellitus, medication, and baseline brachial artery diameter, the heritability of FMD was 0.17 (p=0.01). CONCLUSIONS: We found modest heritability of FMD. FMD might be a reasonable phenotype for further investigation of genetic contribution to atherosclerosis.
Risk of myocardial infarction or vascular death after first ischemic stroke: the Northern Manhattan Study
BACKGROUND AND PURPOSE: In national guidelines, absolute long-term risk of myocardial infarction (MI) or coronary death determines target low-density lipoprotein levels, but stroke patients are not explicitly addressed. We determined the absolute 5-year risk of cardiovascular outcomes and their predictors after first ischemic stroke in a multiethnic cohort. METHODS: A population-based cohort of first ischemic stroke patients > or =40 years old was prospectively followed annually for recurrent stroke, MI and cause-specific mortality. Kaplan-Meier 5-year risks for MI or vascular death (primary outcome), and other cardiovascular events, were calculated. Univariate and multivariate Cox proportional hazards models were used to calculate hazard ratios and 95% CI for predictors of cardiovascular outcomes. RESULTS: Mean age (n=655) was 69.7+/-12.7 years; 55.4% of participants were women, and 51.3% Hispanic. The 5-year risk of MI or vascular death was 17.4% (95% CI, 14.2% to 20.6%). Independent historical predictors of MI or vascular death were age >70 years (hazard ratio 1.62, 1.07 to 2.44), history of coronary artery disease (hazard ratio 1.76, 1.13 to 2.74), and atrial fibrillation (hazard ratio 1.76, 1.05 to 2.94). In the lowest risk group, those < or =70 years old without coronary artery disease, 5-year risk of MI or vascular death was 9.7%. CONCLUSIONS: The absolute risk of MI or vascular death after ischemic stroke, even in those without high-risk features, approximates levels used by national organizations to designate groups of patients at high risk of vascular events. The comparability of levels of absolute risk among stroke and cardiac patients may have treatment implications.
Levels of acute phase proteins remain stable after ischemic stroke
BACKGROUND: Inflammation and inflammatory biomarkers play an important role in atherosclerosis and cardiovascular disease. Little information is available, however, on time course of serum markers of inflammation after stroke. METHODS: First ischemic stroke patients > or =40 years old had levels of high-sensitivity C-reactive protein (hsCRP), serum amyloid A (SAA), and fibrinogen measured in plasma samples drawn at 1, 2, 3, 7, 14, 21 and 28 days after stroke. Levels were log-transformed as needed, and parametric and non-parametric statistical tests were used to test for evidence of a trend in levels over time. Levels of hsCRP and SAA were also compared with levels in a comparable population of stroke-free participants. RESULTS: Mean age of participants with repeated measures (n = 21) was 65.6 +/- 11.6 years, and 13 (61.9%) were men, and 15 (71.4%) were Hispanic. Approximately 75% of patients (n = 15) had mild strokes (NIH Stroke Scale score 0-5). There was no evidence of a time trend in levels of hsCRP, SAA, or fibrinogen for any of the markers during the 28 days of follow-up. Mean log(hsCRP) was 1.67 +/- 1.07 mg/L (median hsCRP 6.48 mg/L) among stroke participants and 1.00 +/- 1.18 mg/L (median 2.82 mg/L) in a group of 1176 randomly selected stroke-free participants from the same community (p = 0.0252). CONCLUSION: Levels of hsCRP are higher in stroke patients than in stroke-free subjects. Levels of inflammatory biomarkers associated with atherosclerosis, including hsCRP, appear to be stable for at least 28 days after first ischemic stroke.
Gender differences in self-report of recovery after stroke: the Northern Manhattan Study
We compared subjective responses to simple questions after stroke with interviewer-assessed stroke outcome measures. Among those in the highest functional category, women were more likely to report incomplete recovery and greater need for help than men. Among these women, depressed mood was associated with a response of a need for help despite a good functional recovery. Self-reported responses in stroke outcome assessments require further validation by gender and may need to consider the confounding effects of depression.
Carotid plaque surface irregularity predicts ischemic stroke: the northern Manhattan study
BACKGROUND AND PURPOSE: There is scant population-based evidence regarding extracranial carotid plaque surface irregularity and ischemic stroke. Using a prospective cohort design, we evaluated the association of carotid plaque surface irregularity and the risk of ischemic stroke in a multiethnic population. METHODS: High-resolution B-mode ultrasound of the carotid arteries was performed in 1939 stroke-free subjects (mean age 69+/-10.0 years; 59% women; 53% Hispanic, 25% black, 22% white). Plaque was defined as a focal protrusion 50% greater than the surrounding area and localized along the extracranial carotid tree (internal carotid artery/bifurcation vs common carotid artery). Plaque surface was categorized as regular or irregular. Cox proportional hazard models were used to assess the association of surface characteristics and the risk of ischemic stroke. RESULTS: Among 1939 total subjects, carotid plaque was visualized in 56.3% (1 plaque: 21.6%, >1 plaque: 34.7%, irregular plaque: 5.5%). During a mean follow up of 6.2 years after ultrasound examination, 69 ischemic strokes occurred. Unadjusted cumulative 5-year risks of ischemic stroke were: 1.3%, 3.0%, and 8.5% for no plaque, regular plaque, and irregular plaque, respectively. After adjusting for demographics, traditional vascular risk factors, degree of stenosis, and plaque thickness, presence of irregular plaque (vs no plaque) was independently associated with ischemic stroke (Hazard ratio, 3.1; 95% CI, 1.1 to 8.5). CONCLUSIONS: The presence of irregular carotid plaque independently predicted ischemic stroke in a multiethnic cohort. Plaque surface irregularities assessed by B-mode ultrasonography may help identify intermediate- to high-risk individuals beyond their vascular risk assessed by the presence of traditional risk factors.
Endothelial dysfunction is associated with carotid plaque: a cross-sectional study from the population based Northern Manhattan Study
BACKGROUND: Impaired vascular function occurs early in atherogenesis. Brachial flow mediated dilatation (FMD) is a non-invasive measure of vascular function and may be an important marker of preclinical atherosclerosis. Data on the association between FMD and carotid plaque in multi-ethnic populations are limited. The objective of this study was to determine whether endothelial dysfunction is independently associated with carotid plaque in a community of northern Manhattan. METHODS: In the population-based Northern Manhattan Study (NOMAS), high-resolution B-mode ultrasound images of the brachial and carotid arteries were obtained in 643 stroke-free subjects (mean age 66 years; 55% women; 65% Caribbean-Hispanic, 17% African-American, 16% Caucasian). Brachial FMD was measured during reactive hyperemia. Maximum carotid plaque thickness (MCPT) was measured at the peak plaque prominence. RESULTS: The mean brachial FMD was 5.78 +/- 3.83 %. Carotid plaque was present in 339 (53%) subjects. The mean MCPT was 1.68 +/- 0.82 mm, and the 75th percentile was 2.0 mm. Reduced FMD was significantly associated with increased MCPT. After adjusting for demographics, vascular risk factors, and education, each percent of FMD decrease was associated with a significant 0.02 mm increase in MCPT (p = 0.028). In a dichotomous adjusted model, blunted FMD was associated with an increased risk of MCPT > or = 2.0 mm (OR, 1.11 for every 1% decrease in FMD; 95% CI, 1.03-1.19). CONCLUSION: Decreased brachial FMD is independently associated with carotid plaque. Non-invasive evaluation of endothelial dysfunction may be a useful marker of preclinical atherosclerosis and help to individualize cardiovascular risk assessment beyond traditional risk factors.
Projected costs of ischemic stroke in the United States
BACKGROUND: There are barriers to acute stroke care in minority groups as well as a higher incidence of ischemic stroke when compared with non-Hispanic whites. OBJECTIVE: To estimate the future economic burden of stroke in non-Hispanic whites, Hispanics, and African Americans in the United States from 2005 to 2050. METHODS: We used U.S. Census estimates of the race-ethnic group populations age 45 years and older. We obtained stroke epidemiology and service utilization data from the Northern Manhattan Stroke Study and the Brain Attack Surveillance in Corpus Christi project and other published data. We estimated costs directly from Medicare reimbursement or from studies that used Medicare reimbursement. Direct and indirect costs considered included ambulance services, initial hospitalization, rehabilitation, nursing home costs, outpatient clinic visits, drugs, informal caregiving, and potential lost earnings. RESULTS: The total cost of stroke from 2005 to 2050, in 2005 dollars, is projected to be 1.52 trillion dollars for non-Hispanic whites, 313 billion dollars for Hispanics, and 379 billion dollars for African Americans. The per capita cost of stroke estimates are highest in African Americans (25,782 dollars), followed by Hispanics (17,201 dollars), and non-Hispanic whites (15,597 dollars). Loss of earnings is expected to be the highest cost contributor in each race-ethnic group. CONCLUSIONS: The economic burden of stroke in African Americans and Hispanics will be enormous over the next several decades. Further efforts to improve stroke prevention and treatment in these high stroke risk groups are necessary.
The association between endothelial dysfunction and cardiovascular outcomes in a population-based multi-ethnic cohort
BACKGROUND: Brachial artery flow-mediated dilation (FMD) may predict cardiovascular events in selected high-risk patients. Whether FMD testing predicts cardiovascular events in asymptomatic, lower risk individuals from the general population is unknown. METHODS AND RESULTS: As a part of a multi-ethnic, prospective cohort study, the Northern Manhattan Study, we examined FMD by high-resolution ultrasonography in 842 community participants who were free of stroke or myocardial infarction. Lower FMD levels predicted cardiovascular events (myocardial infarction, stroke and vascular death) at 36 months of follow-up (hazard ratio (HR)=1.12 for every 1% decrease in FMD, 95% CI 1.01-1.25, p=0.03). The risk of events in patients with FMD in the lower two tertiles (FMD<7.5%) was significantly higher than those in the highest tertile (HR=3.28, 95% CI 1.07-10.06, p=0.04 for lowest versus highest tertile, and HR=3.05, 95% CI 1.03-9.66, p=0.04 for middle versus highest tertile). In a multivariate analysis including cardiovascular risk factors, the increase in risk associated with FMD was no longer statistically significant. CONCLUSIONS: Non-invasive FMD testing predicts incident cardiovascular events in this multi-ethnic, population-based sample, but its predictive value is not independent of cardiovascular risk factors.
Prognostic implications of left ventricular mass among Hispanics: the Northern Manhattan Study
Hispanics may carry a similar burden of increased left ventricular mass (LVM) as non-Hispanic blacks but whether LVM portends a worse outcome among Hispanics is largely unknown. We prospectively evaluated 1081 Hispanics enrolled in the Northern Manhattan Study during the period of 1993 to 2001. Subjects were aged > or =40 years and free of prior myocardial infarction or stroke. LVM was defined echocardiographically and indexed for height(2.7). Cox proportional hazards models were used to assess the risk of vascular events with adjustments for age, gender, systolic blood pressure, diabetes, and smoking. LVM averaged 48.4+/-15 gm/ht(2.7) and on multivariate analysis was significantly associated with the combined end point of myocardial infarction, stroke, or vascular death (adjusted hazard ratio 1.34 per SD change in LVM [95% CI 1.10 to 1.63]). During a mean of 57 months of follow-up, 74 vascular events occurred. The annual rate of vascular events was 21.8 per 1000 patient-years in the highest quartile of LVM and 8.6 per 1000 patient-years in the lowest quartile (P=0.007). These data demonstrate in a large population-based sample that increased LVM yields independent prognostic information among Hispanics, predicting a higher incidence of events attributable to vascular disease in this understudied population. Our findings identify the Hispanic population with increased LVM as a high-risk subgroup.
Alcohol intake, carotid plaque, and cognition: the Northern Manhattan Study
BACKGROUND AND PURPOSE: Moderate alcohol intake has been associated with better cognitive performance, implicating vascular and neurodegenerative processes. Few studies to clarify the importance of vascular disease have included direct measures of atherosclerosis or minority populations at higher risk of vascular disease and dementia. METHODS: The Northern Manhattan Study includes stroke-free community based Hispanic (54%), black (25%), and white (22%) participants. We performed a cross-sectional study of alcohol intake and performance on the Mini-Mental State Examination (MMSE) in subjects with sonographic measurement of maximal carotid plaque thickness and adjusted for sociodemographic and vascular risk factors. RESULTS: The median MMSE score was 27 (interquartile range 24 to 29; n=2215). Reported alcohol intake was divided into 5 groups: never (n=509), past (n=494), <1 drink/week (n=300), 1/week to < or =2 drinks/day (n=796), and >2 drinks/day (n=116). Drinking 1 drink weekly up to 2 daily was associated with better performance on the MMSE (odds ratio=1.19; 95% CI, 1.10 to 1.26) compared with nondrinkers in women (P< or =0.0001) but not in men, adjusting for sociodemographic and vascular risk factors. Maximal carotid plaque thickness (mean 1.1 mm; SD 1.2 mm) was not associated with alcohol intake and did not mediate the relationship between alcohol and cognition. CONCLUSIONS: Moderate alcohol consumption was independently associated with better cognitive performance in women from this multiethnic sample. Carotid plaque was not a mediator of this association suggesting alcohol may impact cognition through a separate vascular or degenerative pathway.
Current understanding of multiple risk factors as the metabolic syndrome: distillation or deconstruction
The "metabolic syndrome" is a new term that defines the clustering of vascular risk factors, such as hyperlipidemia, obesity, elevated blood pressure, and elevated blood glucose. Controversy exists regarding the use of the term, which raises the question of whether the unique grouping of vascular risk factors adds more clinical risk then the additive effect of multiple risk factors viewed as separate but important entities. Whatever the answer, the metabolic syndrome constitutes a major public health problem with over 47 million persons in the United States meeting criteria for the metabolic syndrome. Although studies have demonstrated that the metabolic syndrome is a risk factor for overall mortality as well as cardiovascular events, the relationship between the metabolic syndrome and ischemic stroke has not been well characterized. Two large cross-sectional studies report an association between metabolic syndrome and increased risk of a history of stroke. One large multiethnic prospective study found the metabolic syndrome to be significantly associated with an increased risk of ischemic stroke after adjustment for sociodemographics and other cardiovascular risk factors. This study estimated that the metabolic syndrome may account for 19% of ischemic strokes including 30% of stroke in women and over 40% of stroke in Hispanics. Despite debate about the utility of its definition, there is evidence to suggest that the metabolic syndrome is an important risk factor for ischemic stroke, with differential effects by gender and race-ethnicity. Further, the metabolic syndrome has important clinical and public health implications by helping to easily identify individuals at greatest risk of vascular events.
Factors associated with in-hospital mortality after administration of thrombolysis in acute ischemic stroke patients: an analysis of the nationwide inpatient sample 1999 to 2002
BACKGROUND AND PURPOSE: The prospective trials evaluating the safety and efficacy of intravenous tissue plasminogen activator have generally been conducted at academic medical centers and community hospitals with an institutional commitment to stroke care. Relatively little is known about the safety of this therapy as it is used in the community. We therefore examined outcomes in acute stroke patients treated with thrombolysis using the largest discharge database available in the United States for the years 1999 to 2002. METHODS: Data were derived from the Nationwide Inpatient Sample for the years 1999 to 2002. Using the appropriate International Classification of Disease-Clinical Modification, 9th revision, codes, patients admitted through the emergency room with a primary diagnosis of acute ischemic stroke were selected for analysis. From these patients, those coded as receiving thrombolysis were identified. Multivariate logistic regression was performed on the thrombolysis and nonthrombolysis cohorts to identify independent predictors of in-hospital mortality from among those clinical elements available in the database. RESULTS: We identified 2594 patients treated with thrombolysis from a group of 248,964 patients admitted through the emergency room with a primary diagnosis of acute ischemic stroke. The thrombolysis cohort had a higher in-hospital mortality rate compared with the nonthrombolysis patients (11.4% versus 6.8%). The rate of intracerebral hemorrhage was 4.4% for the thrombolysis cohort and 0.4% for nonthrombolysis patients. Multivariate logistic regression showed advanced age, Asian/Pacific Islander race, congestive heart failure, and atrial fibrillation/flutter to be independent predictors of in-hospital mortality after thrombolysis. Thrombolysis volume, overall ischemic stroke volume, and teaching status were not significant predictors of in-hospital mortality after thrombolysis. CONCLUSIONS: Thrombolysis, as it is used in the community, has a safety profile that is similar to that observed in the large, prospective clinical trials.
Association of increased body mass index and impaired endothelial function among Hispanic women
We tested the hypothesis that an increased body mass index was similarly associated with impaired endothelial function as measured by flow-mediated dilation in a high-risk, Hispanic population of men and women living in northern Manhattan. The association of flow-mediated dilation and body mass index was significant in women (beta -0.16 +/- 0.04, p <0.0001) but not in men (beta -0.02 +/- 0.06, p = 0.72). This is the first study to demonstrate a gender-specific difference in endothelial function associated with body mass index.
Moderate alcohol consumption reduces risk of ischemic stroke: the Northern Manhattan Study
BACKGROUND AND PURPOSE: Moderate alcohol consumption is protective against coronary disease, but its relationship to ischemic stroke (IS) is controversial. METHODS: Stroke-free participants > or =40 years of age identified by random-digit dialing were enrolled in a prospective cohort study between 1993 and 2001. Alcohol consumption was assessed through in-person interview and categorized as none in the past year, > or =1 drink in past month to < or =2 per day (moderate drinkers), and >2 drinks daily. Lifetime drinking was also assessed. Cox proportional hazard regression modeling was used to assess hazard ratios and their 95% CIs for the association of drinking with risk of stroke and vascular events. RESULTS: Mean age among participants (n=3176) was 69.1+/-10.3 years; 62.8% were women, 20.8% were non-Hispanic white, 24.5% non-Hispanic black, and 52.4% were Hispanic. No alcohol in the previous year was present in 62.3%, and 32.5% drank moderately. After adjusting for other risk factors compared with those who did not drink in the past year, moderate drinkers had a reduced risk of IS (0.67; 95% CI, 0.46 to 0.99) and IS, myocardial infarction, or vascular death (0.74; 95% CI, 0.59 to 0.94). Results were similar when never-drinkers were used as referent group. Reduction in risk was seen for nonatherosclerotic IS subtypes, and results stratified by age, sex, and race-ethnicity were similar. CONCLUSIONS: Moderate alcohol consumption is associated with decreased risk of IS in a multiethnic population. This effect is independent of other risk factors and holds for nonatherosclerotic stroke subtypes.
Relation of plasma glucose and endothelial function in a population-based multiethnic sample of subjects without diabetes mellitus
To determine whether endothelial dysfunction precedes the clinical diagnosis of diabetes mellitus, we investigated the relation of endothelial flow-mediated dilation (FMD) with fasting plasma glucose among a multiethnic population-based cohort of 579 nondiabetic subjects without previous myocardial infarction or stroke enrolled in the Northern Manhattan Study (age 66 +/- 9 years; 41% men, 16% white, 15% black, and 68% Hispanic). Impaired fasting glucose or prediabetic status, defined as a fasting glucose level of 100 to 125 mg/dl, was present in 95 subjects (16%). Endothelial function was determined using FMD during reactive hyperemia. Multiple linear regression analyses were used to assess the relation between plasma glucose and endothelial function after adjustment for potential confounders. FMD was significantly lower (4.9 +/- 3.8% vs 6.1 +/- 3.7%, p = 0.003) in those with impaired fasting glucose than in subjects with normal fasting glucose. Prediabetic status was significantly associated with impaired FMD (odds ratio 1.9, 95% confidence interval 1.1 to 3.1, p = 0.02). After adjustment for age, gender, body mass index, and hypertensive status, a higher fasting glucose was significantly associated with a lower FMD (beta = -0.024 +/- 0.012, p = 0.04) in a continuous linear relation. Thus, for each 10-mg/dl increase in plasma glucose, a 0.24% decrease occurred in FMD. Impaired FMD was present among prediabetics. An elevated fasting plasma glucose level is associated with impaired endothelial function among nondiabetics. These results further support the role of hyperglycemia in the pathogenesis of vascular dysfunction at different stages of diabetes development and the role of impaired fasting glucose as a risk factor for macrovascular disease.
Heritability of carotid artery distensibility in Hispanics: the Northern Manhattan Family Study
BACKGROUND AND PURPOSE: Reduced arterial distensibility has been introduced as a novel risk factor for atherosclerosis. The importance of the genetic contribution to variation in distensibility is largely unknown. The purpose of this study was to estimate heritability of carotid distensibility. METHODS: The ongoing Northern Manhattan Family Study recruits high-risk Caribbean Hispanic families to study genetic effects on stroke/cardiovascular risk factors. The distensibility metrics (strain, stiffness, distensibility, and elastic modulus) were measured from the right common carotid artery, and the heritability for each was estimated. Variance component methods were used to estimate age- and sex-adjusted heritability. Correlations were calculated to evaluate the relationship between distensibility phenotypes and intimamedia thickness (IMT) at each carotid segment. RESULTS: The current data included 88 probands and 605 relatives from 88 families. Age- and sex-adjusted heritability was 25% for strain, 17% for distensibility, 20% for stiffness, and 20% for elastic modulus. Without adjustment for covariates, strong correlations were found between distensibility metrics and IMT: the absolute values of correlation coefficients were between 0.2 and 0.5, and all P values were <0.001. However, the correlation coefficients were reduced substantially after adjusting for age and sex. CONCLUSIONS: These results suggested that genetic factors explained a moderate proportion of the variability of carotid distensibility. The correlations between distensibility and IMT were mainly attributable to age and sex effects. The regulation of carotid distensibility and IMT may reflect different underlying genetic and environmental mechanisms.
Heritability of left ventricular mass and other morphologic variables in Caribbean Hispanic subjects: the Northern Manhattan Family Study
Heritabilities of the metabolic syndrome and its components in the Northern Manhattan Family Study
AIMS/HYPOTHESIS: Growing evidence suggests that the traits comprising the metabolic syndrome have a genetic basis. However, studies of genetic contributions to the syndrome are sparse. Against this background, we sought to estimate the heritability of the metabolic syndrome and its component traits. MATERIALS AND METHODS: We investigated 803 subjects from 89 Caribbean-Hispanic families who have enrolled to date in the current Northern Manhattan Family Study and for whom metabolic syndrome information was available. Metabolic syndrome was defined in accordance with the National Cholesterol Education Program Adult Treatment Panel III (NCEP/ATPIII) criteria. Variance component methods were used to estimate age and sex-adjusted heritability of the metabolic syndrome and its components. To obtain the structures underlying the metabolic syndrome, we performed principal component factor analyses using six quantitative phenotypes included in the ATPIII definition. RESULTS: The heritability for the metabolic syndrome was 24% (p=0.009), and ranged from 16 to 60% for its five components. Factor analysis yielded two independent factors (factor 1: lipids/glucose/obesity; factor 2: blood pressure). Heritability analysis revealed significant genetic effects on both factors (44% for lipids/glucose/obesity, and 20% for blood pressure). CONCLUSIONS/INTERPRETATION: In the Caribbean-Hispanic families investigated, we demonstrated moderate and significant heritabilities for the metabolic syndrome itself, as well as for individual components and independent factors of the syndrome. These results provide evidence that could support future tasks of mapping susceptibility loci for this syndrome.
Leukocyte count is associated with reduced endothelial reactivity
BACKGROUND: Leukocyte count has been associated with cardiovascular and cerebrovascular disease in several studies. We hypothesized that white blood cell count is associated with endothelial reactivity. METHODS AND RESULTS: Leukocyte count was measured in a sample of stroke-free community participants undergoing brachial artery testing for endothelial reactivity. Flow-mediated dilation (FMD) during reactive hyperemia was assessed in each subject using high-resolution B-mode ultrasound. Multivariate linear regression was used to calculate the effect of leukocyte count on endothelial reactivity after adjusting for potential confounding factors. Mean age of the 868 participants was 66.7+/-8.8 years; 57% were women. Mean leukocyte count was (6.1+/-1.8)x10(9)/L. Each unit increase in leukocyte count was associated with a mean 0.18% decrease in FMD (p = 0.01). After adjusting for other atherosclerosis risk factors, including age, sex, hypertension, diabetes, hyperlipidemia, and smoking, the relationship persisted (mean decrease in FMD per unit leukocyte count = 0.17%, p = 0.02). There was a linear decrease in FMD by quartile of leukocyte count (p = 0.0014). The effect of leukocyte count on FMD was greater for women, those under age 70, and non-diabetics. CONCLUSIONS: Relative elevations in leukocyte count are associated with a reduction in brachial artery endothelial reactivity. These findings are consistent with current hypotheses regarding the inflammatory or infectious etiology of risk of atherosclerosis and stroke, but also suggest interactions with demographic and other risk factors.
Relative elevation in baseline leukocyte count predicts first cerebral infarction
BACKGROUND: Atherosclerosis is an inflammatory disease, and leukocyte levels are associated with future risk of ischemic cardiac disease. OBJECTIVE: To investigate the hypothesis that relative elevations in leukocyte count in a stroke-free population predict future ischemic stroke (IS). METHODS: A population-based prospective cohort study was performed in a multiethnic urban population. Stroke-free community participants were identified by random-digit dialing. Leukocyte levels were measured at enrollment, and participants were followed annually for IS, myocardial infarction (MI), and cause-specific mortality. Cox proportional hazards regression models were used to calculate hazard ratios (HRs) and 95% CIs for IS, MI, and vascular death after adjustment for medical, behavioral, and socioeconomic factors. RESULTS: Among 3,103 stroke-free community participants (mean age 69.2 +/- 10.3 years) with baseline leukocyte levels measured, median follow-up was 5.2 years. After adjusting for stroke risk factors, each SD in leukocyte count (1.8 x 10(9) cells/L) was associated with an increased risk of IS (HR 1.22, 95% CI 1.05 to 1.42), and IS, MI, or vascular death (HR 1.13, 95% CI 1.02 to 1.26). Compared with those in the lowest quartile of leukocyte count, those in the highest had an increased risk of IS (adjusted HR 1.75, 95% CI 1.08 to 2.82). The effect on atherosclerotic and cardioembolic stroke was greater than in other stroke subtypes. CONCLUSION: Relative elevations in leukocyte count are independently associated with an increased risk of future ischemic stroke and other cardiovascular events.
Social isolation and outcomes post stroke
OBJECTIVE: To assess the relationship between social isolation and stroke outcomes in a multiethnic cohort. METHODS: As part of the Northern Manhattan Stroke Study, the authors prospectively followed a cohort of patients with stroke for 5 years. Baseline data including social isolation were collected. At follow-up, the authors documented outcome events as defined by the first occurrence of myocardial infarction (MI), stroke recurrence, or death. Cox hazard models were used to calculate the hazard ratio (HR, 95% CI) for prestroke predictors of post stroke outcomes. RESULTS: The authors followed 655 ischemic stroke cases for a mean of 5 years. The cohort was 55% women; 17% white, 27% African American, 54% Hispanic; mean age 69 +/- 12 years. There were 265 first outcome events. In univariate analysis, coronary artery disease (OR 1.3, 1.0 to 1.7), age > 70 years (OR 1.9, 1.5 to 2.5), atrial fibrillation (AF) (OR 1.8, 1.3 to 2.5), race-ethnicity (white vs Hispanic) (OR 1.7, 1.1 to 2.9), physical inactivity (OR 1.3, 1.1 to 2.6), help at home (OR 1.8, 1.4 to 2.4), and social isolation (OR 1.4, 1.2 to 1.6) were associated with increased risk of an outcome event. No association was seen for hypertension, diabetes, education, sex, insurance, occupation, marital status, or primary care physician. In the multivariable model controlling for age, AF (OR 1.9, 1.5 to 2.5), help at home (OR 1.5, 1.1 to 2.0), and social isolation (OR 1.4, 1.1 to 1.8) predicted outcome events. CONCLUSION: Prestroke social isolation is a predictor of outcome events post stroke. Lack of social support may contribute to poorer outcomes due to poor compliance, depression, and stress.
Interleukin-2 levels are associated with carotid artery intima-media thickness
OBJECTIVE: To show that serum interleukin levels are associated with carotid intima-media thickness (IMT). BACKGROUND: Inflammation is hypothesized to play a central role in atherogenesis, and serum markers of inflammation are predictive of cardiovascular disease. Interleukin-2, a pro-inflammatory cytokine produced largely by naive CD4 T cells and Th1 (pro-inflammatory) T cells, has been found in a high proportion of carotid plaques. METHODS: High-resolution ultrasound of the carotid arteries and serum cytokine levels were measured in stroke-free participants. The mean of the maximum IMT in bilateral bifurcation, common and internal carotid artery segments was measured. Serum levels of interleukin (IL)-1beta, IL-2, IL-6, C-reactive protein, tumor necrosis factor (TNF) alpha and TNF receptors were measured using enzyme-linked immunosorbent assay. RESULTS: IL-2 levels were significantly correlated with IMT (r=0.33, P<0.0001), but other cytokines were not. Each unit increase in IL-2 was significantly associated with a mean increase in IMT of 0.18 mm (P=0.0001). After adjusting for other atherosclerotic risk factors, the association was unchanged (mean increase in IMT per unit increase IL-2=0.18 mm, P<0.0001). Each standard deviation increase in the level of IL-2 was associated with an increased risk (adjusted odds ratio 1.80, 95% CI 1.12-2.89) for an IMT> or =1.0mm (75th percentile for IMT). CONCLUSION: Serum levels of IL-2, a pro-inflammatory cytokine, are associated with carotid artery IMT, a predictor of stroke and vascular disease. Serum inflammatory markers may provide a novel marker of atherosclerotic risk, and inflammation may provide a new therapeutic target for stroke prevention.
Ischemic stroke subtype incidence among whites, blacks, and Hispanics: the Northern Manhattan Study
BACKGROUND: Stroke incidence is greater in blacks than in whites; data on Hispanics are limited. Comparing subtype-specific ischemic stroke incidence rates may help to explain race-ethnic differences in stroke risk. The aim of this population-based study was to determine ischemic stroke subtype incidence rates for whites, blacks, and Hispanics living in one community. METHODS AND RESULTS: A comprehensive stroke surveillance system incorporating multiple overlapping strategies was used to identify all cases of first ischemic stroke occurring between July 1, 1993, and June 30, 1997, in northern Manhattan. Ischemic stroke subtypes were determined according to a modified NINDS scheme, and age-adjusted, race-specific incidence rates calculated. The annual age-adjusted incidence of first ischemic stroke per 100,000 was 88 (95% CI, 75 to 101) in whites, 149 (95% CI, 132 to 165) in Hispanics, and 191 (95% CI, 160 to 221) in blacks. Among blacks compared with whites, the relative rate of intracranial atherosclerotic stroke was 5.85 (95% CI, 1.82 to 18.73); extracranial atherosclerotic stroke, 3.18 (95% CI, 1.42 to 7.13); lacunar stroke, 3.09 (95% CI, 1.86 to 5.11); and cardioembolic stroke, 1.58 (95% CI, 0.99 to 2.52). Among Hispanics compared with whites, the relative rate of intracranial atherosclerotic stroke was 5.00 (95% CI, 1.69 to 14.76); extracranial atherosclerotic stroke, 1.71 (95% CI, 0.80 to 3.63); lacunar stroke, 2.32 (95% CI, 1.48 to 3.63); and cardioembolic stroke, 1.42 (95% CI, 0.97 to 2.09). CONCLUSIONS: The high ischemic stroke incidence among blacks and Hispanics compared with whites is due to higher rates of all ischemic stroke subtypes.
Periodontal microbiota and carotid intima-media thickness: the Oral Infections and Vascular Disease Epidemiology Study (INVEST)
BACKGROUND: Chronic infections, including periodontal infections, may predispose to cardiovascular disease. We investigated the relationship between periodontal microbiota and subclinical atherosclerosis. METHODS AND RESULTS: Of 1056 persons (age 69+/-9 years) with no history of stroke or myocardial infarction enrolled in the Oral Infections and Vascular Disease Epidemiology Study (INVEST), we analyzed 657 dentate subjects. Among these subjects, 4561 subgingival plaque samples were collected (average of 7 samples/subject) and quantitatively assessed for 11 known periodontal bacteria by DNA-DNA checkerboard hybridization. Extensive in-person cardiovascular risk factor measurements, a carotid scan with high-resolution B-mode ultrasound, white blood cell count, and C-reactive protein values were obtained. In 3 separate analyses, mean carotid artery intima-media thickness (IMT) was regressed on tertiles of (1) burden of all bacteria assessed, (2) burden of bacteria causative of periodontal disease (etiologic bacterial burden), and (3) the relative predominance of causative/over other bacteria in the subgingival plaque. All analyses were adjusted for age, race/ethnicity, gender, education, body mass index, smoking, diabetes, systolic blood pressure, and LDL and HDL cholesterol. Overall periodontal bacterial burden was related to carotid IMT. This relationship was specific to causative bacterial burden and the dominance of etiologic bacteria in the observed microbiological niche. Adjusted mean IMT values across tertiles of etiologic bacterial dominance were 0.84, 0.85, and 0.88 (P=0.002). Similarly, white blood cell values increased across tertiles of etiologic bacterial burden from 5.57 to 6.09 and 6.03 cells x10(9)/L (P=0.01). C-reactive protein values were unrelated to periodontal microbial status (P=0.82). CONCLUSIONS: Our data provide evidence of a direct relationship between periodontal microbiology and subclinical atherosclerosis. This relationship exists independent of C-reactive protein.
Homocysteine and the risk of ischemic stroke in a triethnic cohort: the NOrthern MAnhattan Study
BACKGROUND AND PURPOSE: The level of total homocysteine (tHcy) that confers a risk of ischemic stroke is unsettled, and no prospective cohort studies have included sufficient elderly minority subjects. We investigated the association between mild to moderate fasting tHcy level and the incidence of ischemic stroke, myocardial infarction, and vascular death in a multiethnic prospective study. METHODS: A population-based cohort was followed for vascular events (stroke, myocardial infarction, and vascular death). Baseline values of tHcy and methylmalonic acid were measured among 2939 subjects (mean age, 69+/-10; 61% women, 53% Hispanics, 24% blacks, and 20% whites). Cox proportional models were used to calculate hazard ratios (HRs) and 95% CIs in tHcy categories after adjusting for age, race, education, renal insufficiency, B12 deficiency, and other risk factors. RESULTS: The adjusted HR for a tHcy level > or =15 micromol/L compared with <10 micromol/L was greatest for vascular death (HR=6.04; 95% CI, 3.44 to 10.60), followed by combined vascular events (HR=2.27; 95% CI, 1.51 to 3.43), ischemic stroke (HR=2.01; 95% CI, 1.00 to 4.05), and nonvascular death (HR=2.02; 95% CI, 1.31 to 3.14). Mild to moderate elevations of tHcy of 10 to 15 micromol/L were not significantly predictive of ischemic stroke, but increased the risk of vascular death (2.27; 95% CI, 1.44 to 3.60) and combined vascular events (1.42; 95% CI, 1.06 to 1.88). The effect of tHcy was stronger among whites and Hispanics, but not a significant risk factor for blacks. CONCLUSIONS: Total Hcy elevations above 15 micromol/L are an independent risk factor for ischemic stroke, whereas mild elevations of tHcy of 10 to 15 micromol/L are less predictive. The vascular effects of tHcy are greatest among whites and Hispanics, and less among blacks.
Genetic and environmental contributions to carotid intima-media thickness and obesity phenotypes in the Northern Manhattan Family Study
BACKGROUND AND PURPOSE: Both carotid intima-media thickness (IMT) and obesity are independent determinants of stroke and cardiovascular disease. The prevalence of obesity is higher in Hispanics. The genetic basis of IMT and obesity has not been well-characterized in Caribbean Hispanics. The purpose of this study was to examine the genetic and environmental contributions to IMT and obesity in this population. METHODS: The data included 440 subjects from 77 Caribbean Hispanic families. Mean IMT and maximum IMT were measured in the internal carotid artery, common carotid artery, and carotid bifurcation. The total IMT was calculated as the mean value of IMT at all segments. Obesity phenotypes included body mass index (BMI), waist circumference, waist-to-hip ratio (WHR), and skin-fold thickness. Variance component methods were used to estimate age-adjusted and sex-adjusted heritability. Bivariate analyses were conducted to test for genetic and environmental correlations between IMT and obesity. RESULTS: Heritabilities for IMT ranged from 9% to 40%, with the highest for total maximum IMT and lowest for internal carotid artery maximum IMT. Heritabilities for BMI, waist circumference, WHR, and skin-fold thickness were 44%, 47%, 5%, and 36%, respectively. There were significant genetic, but not environmental, correlations between IMT and BMI, waist circumference, and skin-fold thickness. There were no genetic or environmental correlations between IMT and WHR. CONCLUSIONS: We found a substantial genetic contribution to IMT, BMI, waist circumference, and skin-fold thickness. Obesity and IMT may share common genetic factors. Future gene mapping studies are warranted to identify genes predisposing to IMT and obesity in this population.
Relation between socioeconomic status, race-ethnicity, and left ventricular mass: the Northern Manhattan study
Increased left ventricular mass (LVM) and lower socioeconomic status (SES) are predictors of cardiovascular morbidity and mortality. Blacks and Hispanics are more likely to have higher LVM and lower SES. The relation between SES, race-ethnicity, and LVM has not been fully explored. Data were used from the NOMAS population-based sample of 1916 subjects living in Northern Manhattan. SES was characterized on the basis of educational attainment and divided into 4 categories. Echocardiography-defined LVM was indexed according to height at the allometric power of 2.7 and analyzed as a continuous variable. LVM varied by race in our cohort (blacks 48.9 g/m2.7, Hispanics 48.4 g/m2.7, whites 45.6 g/m2.7; P=0.004). Using ANCOVA, there was a significant inverse and graded association between mean LVM and SES for the total cohort. Mean LVM was 48.4 g/m2.7, 48.6 g/m2.7, 47.1 g/m2.7, and 45.3 g/m2.7 for the lowest to the highest educational level category (P trend=0.0004). This relationship remained among normotensives (P trend=0.0005) and was present for blacks (P trend=0.009), but not for whites (P trend=0.86) or Hispanics (P trend=0.47). The difference in mean LVM between the highest and lowest categories of education was 5.3 g/m2.7 for blacks, 0.0 g/m2.7 for whites, and 1.0 g/m2.7 for Hispanics. Lower SES is an independent predictor of increased LVM among hypertensive and normotensive blacks.
Relationship between periodontal disease, tooth loss, and carotid artery plaque: the Oral Infections and Vascular Disease Epidemiology Study (INVEST)
BACKGROUND AND PURPOSE: Chronic infections, including periodontal infections, may predispose to cardiovascular disease. The present study investigates the relationship of periodontal disease and tooth loss with subclinical atherosclerosis. METHODS: We enrolled 711 subjects with a mean age of 66+/-9 years and no history of stroke or myocardial infarction in the Oral Infections and Vascular Disease Epidemiology Study. Subjects received a comprehensive periodontal examination, extensive in-person cardiovascular disease risk factor measurements, and a carotid scan using high-resolution B-mode ultrasound. Regression models were adjusted for conventional risk factors (age, sex, smoking, diabetes, systolic blood pressure, low- and high-density lipoprotein cholesterol, race-ethnicity, education, physical activity) and markers of cultural background, healthy lifestyle, and psychosocial health. RESULTS: Measures of both current and cumulative periodontitis became more severe as tooth loss increased. A significant association was observed between tooth loss levels and carotid artery plaque prevalence. Among those with 0 to 9 missing teeth, 46% had carotid artery plaque, whereas among those with >or=10 missing teeth, carotid artery plaque prevalence was approximately 60% (P<0.05). CONCLUSIONS: Our data suggest that tooth loss is a marker of past periodontal disease in this population and is related to subclinical atherosclerosis, thereby providing a potential pathway for a relationship with clinical events.
Abdominal obesity and risk of ischemic stroke: the Northern Manhattan Stroke Study
BACKGROUND AND PURPOSE: Obesity is well recognized as a risk factor for coronary heart disease and mortality. The relationship between abdominal obesity and ischemic stroke remains less clear. Our aim was to evaluate abdominal obesity as an independent risk factor for ischemic stroke in a multiethnic community. METHODS: A population-based, incident case-control study was conducted July 1993 through June 1997 in northern Manhattan, New York, NY. Cases (n=576) of first ischemic stroke (66% >or=BORDER="0">65 years of age; 56% women; 17% whites; 26% blacks; 55% Hispanics) were enrolled and matched by age, sex, and race-ethnicity to stroke-free community controls (n=1142). All subjects were interviewed and examined and had measurements of waist-to-hip ratio (WHR). Odds ratios (ORs) of ischemic stroke were calculated with gender-specific quartiles (GQs) and gender-specific medians of WHR adjusted for stroke risk factors and body mass index (BMI). RESULTS: Compared with the first quartile, the third and fourth quartiles of WHR had an increased risk of stroke (GQ3: OR, 2.4; 95% CI, 1.5 to 3.9; GQ4: OR, 3.0; 95% CI, 1.8 to 4.8) adjusted for other risk factors and BMI. Those with WHR equal to or greater than the median had an overall OR of 3.0 (95% CI, 2.1 to 4.2) for ischemic stroke even after adjustment for other risk factors and BMI. Increased WHR was associated with a greater risk of stroke in men and women and in all race-ethnic groups. The effect of WHR was stronger among younger persons (test for heterogeneity, P<0.0002) (<65 years of age: OR, 4.4; 95%CI, 2.2 to 9.0; >or=65 years of age: OR, 2.2; 95% CI, 1.4 to 3.2). WHR was associated with an increased risk among those with and without large-artery atherosclerotic stroke. CONCLUSIONS: Abdominal obesity is an independent, potent risk factor for ischemic stroke in all race-ethnic groups. It is a stronger risk factor than BMI and has a greater effect among younger persons. Prevention of obesity and weight reduction need greater emphasis in stroke prevention programs.
Obstacle training programme for individuals post stroke: feasibility study
OBJECTIVE: The purposes were threefold: to develop an obstacle ambulation training programme, to recruit and retain individuals post chronic stroke and to assess the effectiveness of the obstacle ambulation training programme. DESIGN: Intervention study; case series; baseline to post-intervention measures and one month follow-up after intervention. SETTING: An outpatient department. SUBJECTS: Five individuals with chronic stroke with mild to moderate functional limitations; convenience sample. INTERVENTIONS: Therapy consisted of twice weekly sessions for four weeks during which subjects walked along a walkway and over obstacles. MAIN OUTCOME MEASURES: Motor Assessment Scale--walking section (MAS--time), Six-minute Walk Test distance, walking velocity, and Medical Outcomes Study-36 Health Status Measurement (SF-36). RESULTS: Significant improvements were seen baseline to post intervention for walking velocity, Six-minute Walk Test, MAS and SF-36 physical function score (p < or = 0.025 for all measures). Most improvements noted at the end of training were retained one month later. The effect sizes ranged from 0.33 to 1.20. CONCLUSIONS: Substantial improvement in ambulation function and disability level were seen as a result of the obstacle training programme for individuals with chronic stroke. Further investigation is warranted.
Stroke in the young in the northern Manhattan stroke study
BACKGROUND AND PURPOSE: Stroke and stroke subtype incidence in young black and Hispanic populations have not been well studied. The purpose of this study was to determine stroke incidence rates in these populations and to compare rates among various race-ethnic, sex, and age groups. METHODS: A population-based incidence study identified all cases of first stroke in Northern Manhattan from 1993 to 1997. Stroke and stroke subtype incidence rates were calculated for younger (20 to 44 years of age) and older (>/=45 years of age) adults. The relative risk (RR) of stroke in blacks and Hispanics compared with whites was calculated. Stroke subtypes, infarct subtypes, and case fatality rates were compared in the young and old and in different race-ethnic groups and sexes. RESULTS: Over 4 years, 74 cases of first stroke in young patients were discovered (47% women, 12% black, 80% Hispanic, 8% white). The stroke incidence rates (cases per 100 000 persons per year) in the young were 23 overall, 10 for infarct, 7 for intracerebral hemorrhage (ICH), and 6 for subarachnoid hemorrhage. The RR of stroke in the young was greatest for blacks (2.4; 95% CI, 0.8 to 6.7) and Hispanics (2.5; 95% CI, 1.1 to 5.8) compared with whites. ICH was more frequent in men with a RR of 3.7 (95% CI, 1.4 to 10.1). Case fatality rates at 30 days were higher in blacks (38%) and Hispanics (16%) compared with whites (0%). CONCLUSIONS: Young blacks and Hispanics have greater stroke incidences than young whites.
Apolipoproteins and carotid artery atherosclerosis in an elderly multiethnic population: the Northern Manhattan stroke study
The association of apolipoproteins A-I and B (apo A-I and apo B) with cardiovascular disease has been studied in younger populations, but there is sparse information in the elderly. We determined whether apo A-I and apo B were associated with carotid artery atherosclerosis (CAA) in 507 stroke-free elderly community residents (mean age 70.1+/-11.7 years, 60% women, 41% Hispanics, 30% African American, 28% Caucasian). CAA severity was normal (no plaque or carotid stenosis) in 39%, mild (maximum plaque thickness < or =1.8 mm or carotid stenosis <40%) in 25%, and moderate/severe (maximum plaque thickness >1.8 mm or carotid stenosis > or =40%) in 36%. CAA severity increased with age in all race/ethnic groups (P<0.01). CAA was similar among African Americans and Caucasians, but less in Hispanics (age adjusted OR: 0.5, CI: 0.4-0.8). apo A-I <1.2 g/l (OR: 2.0, CI: 1.0-3.3) and apo B > or =1.4 g/l (OR: 2.0, CI: 1.1-3.6) were associated with moderate-severe CAA. An apo B/apo A-I ratio > or =1 was associated with moderate-severe CAA (OR: 2.4, CI: 1.3-4.4), and the association varied by race (Hispanics OR: 4.3, CI: 1.8-10; non-Hispanics, OR: 1.4, CI: 0.6-3.2). Total cholesterol, triglycerides and low density lipoprotein cholesterol were not associated with moderate-severe CAA, while high density lipoprotein cholesterol was protective (OR: 0.4, CI: 0.2-0.8). Thus, in an elderly population, apo A-I and B were determinants of moderate-severe CAA, and the degree of association varied by race/ethnicity
Leukocyte count is associated with aortic arch plaque thickness
BACKGROUND AND PURPOSE: Leukocyte count has been associated with cardiovascular and cerebrovascular disease, including carotid plaque thickness, in several studies. We hypothesized that white blood cell count is associated with aortic arch plaque thickness (AAPT). METHODS: Leukocyte count was measured in randomly selected stroke-free community participants undergoing transesophageal echocardiography. AAPT was measured for each subject and dichotomized into <4 and > or =4 mm (thick plaque). Multivariate linear and logistic regression was used to calculate the effect of leukocyte count on AAPT after adjustment for potential confounding factors. Mean age of the 145 participants was 68.5+/-8.3 years; 43.5% were women; 15.9% were white; 31.7% were black; and 49.0% were Hispanic. RESULTS: Mean leukocyte count was 5.88+/-1.76x10(9)/L. Each unit increase in leukocyte count was associated with a mean 0.28-mm increase in AAPT (P=0.0036). After adjustment for other atherosclerosis risk factors, including age, sex, hypertension, diabetes, hyperlipidemia, and smoking, the relationship persisted (mean increase in AAPT, 0.24 mm; P=0.0064). Thirty-five participants (24.1%) had AAPT > or =4 mm. Mean leukocyte count among those with thick plaque was significantly higher than among those with plaque <4 mm (6.54+/-1.60 versus 5.65+/-1.76x10(9)/L, respectively; P=0.009). Each unit increase in leukocyte count was associated with an increased risk of thick plaque (adjusted odds ratio, 1.38; 95% CI, 1.05 to 1.79). The relationships were similar for men and women and for those <70 or > or =70 years of age. CONCLUSIONS: Leukocyte count is associated with AAPT and is specifically correlated with AAPT > or =4 mm, a degree of thickening associated with increased stroke risk. These findings are consistent with current hypotheses regarding the inflammatory or infectious etiology of risk of atherosclerosis and stroke.
Carotid intima-media thickness is associated with allelic variants of stromelysin-1, interleukin-6, and hepatic lipase genes: the Northern Manhattan Prospective Cohort Study
BACKGROUND AND PURPOSE: Atherosclerosis is a complex disorder with hereditary and environmental causes. Carotid artery intima-media wall thickness (IMT) is a useful measure of atherosclerosis. The objective of this study was to determine the association between carotid IMT and functional promoter variants of stromelysin-1 (MMP3: -1612 5A>6A), interleukin-6 (IL6: -174G>C), and hepatic lipase (HL: -480C>T) genes. METHODS: B-mode carotid ultrasound was performed among 87 subjects (mean age, 70+/-12 years; 55% women; 60% Caribbean-Hispanic, 25% black, and 13% white) from the Northern Manhattan Prospective Cohort Study. Carotid IMT was calculated as a composite measure (mean of the maximum IMT in the bifurcation, the common carotid artery, and the internal carotid artery). RESULTS: For all polymorphisms, genotype distribution was not significantly different from Hardy-Weinberg equilibrium. The frequencies of the rare alleles were as follows: MMP3 -1612 5A>6A, 0.31 (95% CI, 0.25 to 0.39); IL6 -174 G>C, 0.20 (95% CI, 0.13 to 0.25); and HL -480 C>T, 0.45 (95% CI, 0.35 to 0.50). Carotid IMT in the sample was 0.78+/-0.18 mm. Subjects with the MMP3 genotype 6A6A had 8% greater mean carotid IMT than the other MMP3 genotypes combined (0.95+/-0.17 versus 0.87+/-0.15 mm; P=0.04). Subjects with the IL6 genotype GG had 11% greater IMT (0.85+/-0.17 versus 0.76+/-0.16 mm; P=0.03), and those with the HL genotype CC had 13% greater IMT (0.87+/-20 versus 0.76+/-0.18 mm; P=0.02) than the other genotypes combined. Adjustment for other risk factors did not change these associations. CONCLUSIONS: Carotid IMT is higher among subjects homozygous for functional variants in genes related to matrix deposition (MMP3 -16126A), inflammation (IL6 -174G), and lipid metabolism (HL -480C). These associations were independent of race-ethnicity and some environmental exposures. Further studies are needed to confirm these genotype-phenotype associations.
Physical activity attenuates the effect of increased left ventricular mass on the risk of ischemic stroke: The Northern Manhattan Stroke Study
OBJECTIVES: The goal of this study was to determine whether the risk of ischemic stroke associated with increased left ventricular mass (LVM) is modified by physical activity (PA). BACKGROUND: Increased LVM is associated with an increased risk for stroke. Physical activity can decrease the risk of stroke and may have variable effects on LVM. METHODS: We used a case-control study design in a multiethnic population in northern Manhattan, New York, to study 394 case subjects who had a first ischemic stroke and 413 stroke-free control subjects. All subjects were interviewed and two-dimensional echocardiograms obtained to determine LVM. RESULTS: A sharp increase in risk of ischemic stroke was seen in the highest quartile of LVM (odds ratio [OR]: 6.14 [95% confidence interval [CI]: 3.04 to 12.38]). Thus, increased LVM was defined by the highest quartile of LVM. In multivariate analysis, the effect of increased LVM on the risk of stroke was significantly decreased by the presence of any level of PA versus no PA (OR: 1.59 [95% CI: 0.99 to 2.57] p < 0.07 vs. 3.53 [95% CI: 1.94 to 6.42] p < 0.0001). Although PA decreased the risk of stroke in all patients, the effect was stronger in subjects with increased LVM than among those without increased LVM (p = 0.033). CONCLUSIONS: Increased LVM is associated with an increased risk of stroke, especially among sedentary patients. Physical activity decreases the risk of stroke among patients with increased LVM to a level comparable to that of patients without increased LVM. Recommending PA may be a nonpharmacologic tool to reduce the stroke risk, especially among patients with increased LVM.
Relation of Apo(a) size to carotid atherosclerosis in an elderly multiethnic population
Lipoprotein(a) [Lp(a)] is a novel risk factor for atherosclerosis, whose role in multiracial populations has been debated. We recently demonstrated a significant association of elevated levels of Lp(a) carried in particles containing small apolipoprotein(a) [apo(a)] isoforms with coronary artery disease in African American and white men. To extend these findings, we investigated the associations between Lp(a) levels, apo(a) size, and maximum internal carotid artery plaque thickness (MPT) in a randomly selected elderly multiethnic population (173 men and 253 women, consisting of 135 African Americans, 146 Hispanics, and 145 whites; mean age 70.5+/-11.4 years). Lp(a) levels were not associated with MPT. Among white men, MPT was associated with a small apo(a) isoform size (P=0.03) as well as with the amount of Lp(a) carrying the small apo(a) size (P=0.04), and the latter showed a borderline association in African American men (P=0.07). Among white women, but not in Hispanic or African American women, MPT was associated with the amount of Lp(a) carrying a small apo(a) isoform size (P<0.01). For all patients, the amount of Lp(a) carrying the small apo(a) size was associated with carotid atherosclerosis when there was control for age, sex, ethnicity, high density lipoprotein cholesterol, low density lipoprotein cholesterol, triglycerides, diabetes mellitus, hypertension, waist-to-hip ratio, and current smoking status (P=0.03). This association was significant for all men (P=0.03) and for white women (P=0.007). The results suggest that molecular properties of apo(a) are important in determining the atherogenicity of Lp(a).
Tumor necrosis factor receptor levels are associated with carotid atherosclerosis
BACKGROUND AND PURPOSE: Recent evidence suggests that atherosclerosis is an inflammatory condition. Serum levels of inflammatory markers may serve as measures of the severity of atherosclerosis and risk of stroke. We sought to determine whether tumor necrosis factor-alpha (TNF-alpha) and TNF receptor levels are associated with carotid plaque thickness. METHODS: The Northern Manhattan Stroke Study is a community-based study of stroke risk factors. For this cross-sectional analysis, inflammatory marker levels, including TNF-alpha and TNF receptors 1 and 2, were measured by immunoassay in stroke-free community subjects undergoing carotid duplex Doppler ultrasound. Maximal carotid plaque thickness (MCPT) was measured for each subject. Analyses were stratified by age < 70 and > or =70 years. Simple and multiple linear regression analyses were used to calculate the association between marker levels and MCPT. Multiple logistic regression was used to calculate odds ratios and 95% CIs for the association of inflammatory markers with MCPT > or =1.5 mm (>75th percentile), after adjustment for demographic and potential medical confounding factors. RESULTS: The mean age of the 279 subjects was 67.6+/-8.5 years; 49% were men; 63% were Hispanic, 17% black, and 17% white. Mean values for TNF-alpha and its receptors were as follows: TNF-alpha, 1.88+/-3.97 ng/mL; TNF receptor 1, 2.21+/-0.99 ng/mL; and TNF receptor 2, 4.85+/-2.23 ng/mL. Mean MCPT was elevated in those in the highest quartiles compared with lowest quartiles of TNF receptor 1 and 2 (1.24 versus 0.79 mm and 1.23 versus 0.80 mm, respectively). Among those aged < 70 years, TNF receptor 1 and 2 were associated with an increase in MCPT (mean difference=0.36 mm, P=0.01 for TNF receptor 1 and mean difference=0.10 mm, P=0.04 for TNF receptor 2). After adjustment for sex, race-ethnicity, hypertension, diabetes mellitus, LDL cholesterol, smoking, and body mass index, associations remained (mean difference=0.36 mm, P=0.001 for TNF receptor 1 and mean difference=0.09 mm, P=0.051 for TNF receptor 2). There was no association for TNF receptors in those aged > or = 70 years old and no association for TNF-alpha in either age group. Among those aged < 70 years, each unit increase in TNF receptor level increased the odds of the participant's having MCPT > or =1.5 mm (adjusted odds ratio=4.7; 95% CI, 1.7 to 15.4 for TNF receptor 1; odds ratio=1.9; 95% CI, 1.3 to 2.9 for TNF receptor 2). CONCLUSIONS: Relative elevation in TNF receptor levels, but not TNF-alpha, is associated with carotid atherosclerosis among individuals aged < 70 years in this multiethnic, urban population. Chronic subclinical infection or inflammation may account for this association, and modification of these inflammatory pathways may provide a novel approach to stroke prevention.
Race-ethnic disparities in the impact of stroke risk factors: the northern Manhattan stroke study
BACKGROUND AND PURPOSE: Stroke risk factors have been determined in large part through epidemiological studies in white cohorts; as a result, race-ethnic disparities in stroke incidence and mortality rates remained unexplained. The aim in the present study was to compare the prevalence, OR, and etiological fraction (EF) of stroke risk factors among white, blacks, and Caribbean Hispanics living in the same urban community of northern Manhattan. METHODS: In this population-based incident case-control study, cases (n=688) of first ischemic stroke were prospectively matched 1:2 by age, sex, and race-ethnicity with community controls (n=1156). Risk factors were determined through in-person assessment. Conditional logistic regression was used to calculate adjusted ORs in each race-ethnic group. Prevalence and multivariate EFs were determined in each race-ethnic group. RESULTS: Hypertension was an independent risk factor for whites (OR 1.8, EF 25%), blacks (OR 2.0, EF 37%), and Caribbean Hispanics (OR 2.1, EF 32%), but greater prevalence led to elevated EFs among blacks and Caribbean Hispanics. Greater prevalence rates of diabetes increased stroke risk in blacks (OR 1.8, EF 14%) and Caribbean Hispanics (OR 2.1 P<0.05, EF 10%) compared with whites (OR 1.0, EF 0%), whereas atrial fibrillation had a greater prevalence and EF for whites (OR 4.4, EF 20%) compared with blacks (OR 1.7, EF 3%) and Caribbean Hispanics (OR 3.0, EF 2%). Coronary artery disease was most important for whites (OR 1.3, EF 16%), followed by Caribbean Hispanics (OR 1.5, EF 6%) and then blacks (OR 1.1, EF 2%). Prevalence of physical inactivity was greater in Caribbean Hispanics, but an elevated EF was found in all groups. CONCLUSIONS: The prevalence, OR, and EF for stroke risk factors vary by race-ethnicity. These differences are crucial to the etiology of stroke, as well as to the design and implementation of stroke prevention programs.
High-density lipoprotein cholesterol and ischemic stroke in the elderly: the Northern Manhattan Stroke Study
CONTEXT: Elevated high-density lipoprotein cholesterol (HDL-C) levels have been shown to be protective against cardiovascular disease. However, the association of specific lipoprotein classes and ischemic stroke has not been well defined, particularly in higher-risk minority populations. OBJECTIVE: To evaluate the association between HDL-C and ischemic stroke in an elderly, racially or ethnically diverse population. DESIGN: Population-based, incident case-control study conducted July 1993 through June 1997. SETTING: A multiethnic community in northern Manhattan, New York, NY. PARTICIPANTS: Cases (n = 539) of first ischemic stroke (67% aged >/=65 years; 55% women; 53% Hispanic, 28% black, and 19% white) were enrolled and matched by age, sex, and race or ethnicity to stroke-free community residents (controls; n = 905). MAIN OUTCOME MEASURE: Independent association of fasting HDL-C levels, determined at enrollment, with ischemic stroke, including atherosclerotic and nonatherosclerotic ischemic stroke subtypes. RESULTS: After risk factor adjustment, a protective effect was observed for HDL-C levels of at least 35 mg/dL (0.91 mmol/L) (odds ratio [OR], 0.53; 95% confidence interval [CI], 0.39-0.72). A dose-response relationship was observed (OR, 0.65; 95% CI, 0.47-0.90 and OR, 0.31; 95% CI, 0.21-0.46) for HDL-C levels of 35 to 49 mg/dL (0.91-1.28 mmol/L) and at least 50 mg/dL (1.29 mmol/L), respectively. The protective effect of a higher HDL-C level was significant among participants aged 75 years or older (OR, 0.51; 95% CI, 0.27-0.94), was more potent for the atherosclerotic stroke subtype (OR, 0.20; 95% CI, 0.08-0.50), and was present in all 3 racial or ethnic groups studied. CONCLUSIONS: Increased HDL-C levels are associated with reduced risk of ischemic stroke in the elderly and among different racial or ethnic groups. These data add to the evidence relating lipids to stroke and support HDL-C as an important modifiable stroke risk factor.
Elevated white blood cell count and carotid plaque thickness : the northern manhattan stroke study
BACKGROUND AND PURPOSE: Elevated leukocyte count has been associated with cardiovascular and cerebrovascular disease in several epidemiological studies. We sought to determine whether white blood cell count (WBC) is associated with carotid plaque thickness in a stroke-free, multiethnic cohort. METHODS: For this cross-sectional analysis, WBC was measured in stroke-free community subjects undergoing carotid duplex Doppler ultrasound. Maximal internal carotid plaque thickness (MICPT) was measured for each subject. Demographic and potential medical confounding factors were analyzed with linear and logistic regression to calculate the effect of quartile of WBC on MICPT. Odds ratios (ORs) and 95% confidence intervals (CIs) for the effect of quartile of WBC on MICPT >/=75th percentile were calculated. All analyses were stratified by race-ethnicity. RESULTS: The mean age of the 1422 subjects was 68.6+/-10.2 years; 40.0% were men; 24.4% were white, 46.9% Hispanic, and 26.7% black. Among Hispanics, compared with the lowest quartile of WBC, those in the highest quartile had significantly increased MICPT (mean difference=0.30 mm, P:=0.0086) after adjustment for age, sex, and other atherosclerotic risk factors. There was no significant increase for blacks or whites. The OR for MICPT >/=75th percentile (1.9 mm) was significantly increased for Hispanics (OR, 2.8; 95% CI, 1.4 to 5.6), marginally elevated for black non-Hispanics (OR, 1.6; 95% CI, 0.8 to 3.2), and not increased for white non-Hispanics (OR, 0.5; 95% CI, 0.2 to 1.1). CONCLUSIONS: Relative elevation in WBC is associated with carotid atherosclerosis, but this relationship differs by race-ethnicity. The association is strongest in Hispanics, intermediate in black non-Hispanics, and not present in white non-Hispanics in this population. Chronic subclinical infection or inflammation may account for this association.
Cost and outcome of mechanical ventilation for life-threatening stroke
BACKGROUND AND PURPOSE: Hospital mortality rates of 50% to 90% have been reported for stroke patients treated with mechanical ventilation. These data have raised serious questions about the cost-effectiveness of this intervention. We sought to determine how often stroke patients are mechanically ventilated, identify predictors of 30-day survival among ventilated patients, and evaluate the cost-effectiveness of this intervention. METHODS: We identified mechanically ventilated patients in a population-based multiethnic cohort of 510 incidence stroke patients who were hospitalized between July 1993 and June 1996. Factors affecting 30-day survival were identified in a multiple logistic regression analysis. We calculated the cost per patient discharged alive, life-year saved, and quality-adjusted life-year saved using a zero-cost, zero-life assumption. RESULTS: Ten percent of patients (n=52) were mechanically ventilated. Thirty-day mortality was 65% overall and did not differ significantly by stroke subtype. Glasgow Coma Scale score on the day of intubation (P:<0.01) and subsequent neurological deterioration (P:=0.02) were identified as predictors of 30-day mortality. The cost (1996 US dollars) of hospitalization per patient discharged alive was $89 400; the cost per year of life saved was $37 600; and the cost per quality-adjusted life-year saved was $174 200. Functional status of most survivors was poor; at 6 months, half were severely disabled and completely dependent. In a worst-case scenario of quality of life preferences, mechanical ventilation resulted in a net deficit of meaningful survival. CONCLUSIONS: Two thirds of mechanically ventilated stroke patients die during their hospitalization, and most survivors are severely disabled. Survival is particularly unlikely if patients are deeply comatose or clinically deteriorate after intubation. In our multiethnic urban population, mechanical ventilation for stroke was relatively cost-effective for extending life but not for preserving quality of life.
Association of hyperandrogenemia and hyperestrogenemia with type 2 diabetes in Hispanic postmenopausal women
OBJECTIVE: Accumulating evidence suggests that hyperandrogenemia may be a risk factor for coronary heart disease (CHD) in women. The present study was carried out to test the hypothesis that hyperandrogenemia is associated with type 2 diabetes in women and thus may contribute to the increased risk of CHD in women with type 2 diabetes. RESEARCH DESIGN AND METHODS: Sex hormones, sex hormone-binding globulin (SHBG), and risk factors for CHD were measured in 20 postmenopausal women with type 2 diabetes and in 29 control subjects. All of the diabetic and control subjects were Hispanic women aged >55 years who were not taking hormone replacement therapy lipid-lowering drugs, or insulin and who were otherwise randomly chosen from a cohort of stroke-free subjects from the Northern Manhattan Stroke Study RESULTS: Mean age, BMI, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, blood pressure, and smoking were not significantly different between cases and control subjects, but waist-to-hip ratio (WHR) was significantly higher in the diabetic subjects (P = 0.01). The mean levels of free testosterone (FT) (P = 0.01), dehydroepiandrosterone sulfate (P<0.04), and estradiol (P = 0.01) (controlled for WHR) were significantly higher in the diabetic subjects; with the statistical outliers removed, the testosterone (P = 0.05) and androstenedione (P = 0.002) levels (controlled for WHR) were also significantly higher in the diabetic subjects. The mean levels of estrone, cortisol, and SHBG were not significantly different. The results were similar in the 10 diabetic subjects treated with diet only Significant positive correlations (controlled for age and BMI) were observed between FT or testosterone and cholesterol, LDL cholesterol, and blood pressure. CONCLUSIONS: Postmenopausal Hispanic women with type 2 diabetes had both hyperandrogenemia and hyperestrogenemia, and testosterone or FT correlated positively with risk factors for CHD. Hyperandrogenemia may be a link between diabetes and CHD in women.
Coding neuroradiology reports for the Northern Manhattan Stroke Study: a comparison of natural language processing and manual review
Automated systems using natural language processing may greatly speed chart review tasks for clinical research, but their accuracy in this setting is unknown. The objective of this study was to compare the accuracy of automated and manual coding in the data acquisition tasks of an ongoing clinical research study, the Northern Manhattan Stroke Study(NOMASS). We identified 471 neuroradiology reports of brain images used in the NOMASS study. Using both automated and manual coding, we completed a standardized NOMASS imaging form with the information contained in these reports. We then generated ROC curves for both manual and automated coding by comparing our results to the original NOMASS data, where study in investigators directly coded their interpretations of brain images. The areas under the ROC curves for both manual and automated coding were the main outcome measure. The overall predictive value of the automated system (ROC area 0.85, 95% CI 0.84-0.87) was not statistically different from the predictive value of the manual coding (ROC area 0.87, 95% CI 0.83-0.91). Measured in terms of accuracy, the automated system performed slightly worse than manual coding. The overall accuracy of the automated system was 84% (CI 83-85%). The overall accuracy of manual coding was 86% (CI 84-88%). The difference in accuracy between the two methods was small but statistically significant (P = 0.026). Errors in manual coding appeared to be due to differences between neurologists' and nueroradiologists' interpretation, different use of detailed anatomic terms, and lack of clinical information. Automated systems can use natural language processing to rapidly perform complex data acquisition tasks. Although there is a small decrease in the accuracy of the data as compared to traditional methods, automated systems may greatly expand the power of chart review in clinical research design and implementation.
The stroke prognosis instrument II (SPI-II) : A clinical prediction instrument for patients with transient ischemia and nondisabling ischemic stroke
BACKGROUND AND PURPOSE: In 1991 we developed the Stroke Prognosis Instrument (SPI-I) to stratify patients with transient ischemic attack or ischemic stroke by prognosis for stroke or death in 2 years. In this article we validate and improve SPI-I (creating SPI-II). METHODS: To validate SPI-I, we applied it to 4 test cohorts and calculated pooled outcome rates. To create SPI-II, we incorporated new predictive variables identified in 1 of the test cohorts and validated it in the other 3 cohorts. RESULTS: For SPI-I, pooled rates (all 4 test cohorts) of stroke or death within 2 years in risk groups I, II, and III were 9%, 17%, and 24%, respectively (P<0.01, log-rank test). SPI-II was created by adding congestive heart failure and prior stroke to SPI-I. Each patient's risk group was determined by the total score for 7 factors: congestive heart failure (3 points); diabetes (3 points); prior stroke (3 points); age >70 years (2 points); stroke for the index event (not transient ischemic attack) (2 points); hypertension (1 point); and coronary artery disease (1 point). Risk groups I, II, and III comprised patients with 0 to 3, 4 to 7, and 8 to 15 points, respectively. For SPI-I, pooled rates (3 cohorts excluding the SPI-II development cohort) of stroke or death within 2 years in risk groups I, II, and III were 9%, 17%, and 23%, respectively. For SPI-II, pooled rates were 10%, 19%, and 31%, respectively. In receiver operator characteristic analysis, the area under the curve was 0.59 (95% CI, 0.57 to 0.60) for SPI-I and 0.63 (95% CI, 0.62 to 0.65) for SPI-II, confirming the better performance of the latter. CONCLUSIONS: Compared with SPI-I, SPI-II achieves greater discrimination in outcome rates among risk groups. SPI-II is ready for use in research design and may have a role in patient counseling.
Validity of telephone interview data for vascular disease risk factors in a racially mixed urban community: the Northern Manhattan Stroke Study
The aims of our study were to assess the validity and reliability of a telephone survey instrument designed to measure vascular disease risk factors and to assess whether these measurements were influenced by age, gender, race/ethnicity, or other sociodemographic variables. Subjects were sampled and interviewed using random digit dialing methodology from the multiethnic community of northern Manhattan. For the validity study, 261 consecutive subjects were clinically assessed in-person within 60 days of the telephone interview. A retest reliability study of the telephone interview was conducted in 92 randomly selected subjects within 30 days of the initial interview. The telephone interview instrument had a sensitivity of more than 55% and a specificity of 74% or greater for various vascular disease risk factors. Sensitivity, specificity, and positive predictive value did not vary significantly or systematically among whites, blacks, and Hispanics, but subjects with access to health care were more likely to provide valid data. The reliability substudy indicated a good reliability for the telephone interview. These results support the validity of telephone interviews for estimating the prevalence of vascular risk factors in urban populations.
The protective effect of moderate alcohol consumption on ischemic stroke
CONTEXT: Moderate alcohol consumption has been shown to be protective for coronary heart disease, but the relationship between moderate alcohol consumption and ischemic stroke is more controversial. OBJECTIVE: To determine the association between alcohol consumption and risk of ischemic stroke. DESIGN: Population-based case-control study conducted between July 1993 and June 1997. SETTING: Multiethnic population in northern Manhattan, New York, NY, aged 40 years or older. PATIENTS AND OTHER PARTICIPANTS: Cases (n = 677) had first ischemic stroke and were matched to community controls (n = 1139) derived through random digit dialing by age, sex, and race/ethnicity. Mean +/- SD age of cases was 70.0+/-12.7 years; 55.8% were women; 19.5% were white, 28.4% black, and 50.7% Hispanic. MAIN OUTCOME MEASURE: First ischemic stroke (fatal or nonfatal). RESULTS: Moderate alcohol consumption, up to 2 drinks per day, was significantly protective for ischemic stroke after adjustment for cardiac disease, hypertension, diabetes, current smoking, body mass index, and education (odds ratio [OR], 0.51; 95% confidence interval [CI], 0.39-0.67). This protective effect of alcohol consumption was detected in both younger and older groups, in men and women, and in whites, blacks, and Hispanics. In a quadratic model of stroke risk, increased risk of ischemic stroke was statistically significant among those consuming 7 or more drinks per day (OR, 2.96; 95% CI, 1.05-8.29). CONCLUSIONS: Moderate alcohol consumption was independently associated with a decreased risk of ischemic stroke in our elderly, multiethnic, urban subjects, while heavy alcohol consumption had deleterious effects. Our data support the National Stroke Association Stroke Prevention Guidelines regarding the beneficial effects of moderate alcohol consumption.
Social readjustment and ischemic stroke: lack of an association in a multiethnic population
Clinical experience has suggested that stressful life events and ongoing stressful illness, collectively termed 'social readjustment', may precipitate stroke. We investigated the association between a simple in-office evaluation of such stressors and stroke in an urban, multiethnic study population. Cases were patients from the Northern Manhattan Stroke Study with first ischemic stroke; controls were derived through random digit dialing with n:m matching for age, gender, and race-ethnicity. Social readjustment was measured through in-person interview using Amster and Krauss' Geriatric Social Readjustment Rating Scale (GSRRS), a one-time, 35-item, checklist type weighted questionnaire of stressful life events occurring in the previous 6 months. Conditional logistic regression was used to analyze the GSRRS and its quartiles as well as stressful events subgroups, adjusting for education, hypertension, cardiac disease, diabetes, and number of weekly visits as a measure of socialization. Six hundred and fifty-five cases of ischemic stroke and 1,087 controls were utilized. The mean age of the cases was 69.8 years, with 55.4% women, 51.0% Hispanics, 28.4% blacks, and 19.1% whites. GSRRS scores ranged from 0 to 812; the mean score was 205.5 for the cases and 206.2 for the controls. The analysis showed no association between stroke and a 20-point increase on the GSRRS (OR = 1.01, 95% CI = 0.99-1.01). There was also no effect for the second, third or highest versus lowest quartile. No association was found in age, gender or race-ethnic subgroups, or when analyzing negative events, severely threatening events, or ongoing stressful illnesses separately. While this study does not preclude social readjustment as a stroke risk factor, it suggests that the one-time assessment often done in the medical office setting has little relevance for stroke prevention planning.
Lipid and lipoprotein levels remain stable in acute ischemic stroke: the Northern Manhattan Stroke Study
Serum lipoproteins including lipoprotein(a), Lp(a), are emerging as possible biological markers for cerebrovascular disease. Existing data on Lp(a) and serum lipids levels following acute ischemic stroke (AIS) are however equivocal. To determine whether serum Lp(a) and other lipid levels obtained within 24 h of acute ischemic stroke onset changed over the ensuing 4 weeks and whether these levels are related to an acute phase response, acquired nutritional deficiency, and neurovascular data, we conducted repeated measurement analyses among 19 subjects (mean age 65.0 +/- 12.1 years; 32% women) presenting with AIS (evaluated within 9.7 +/- 12.7 h). Eleven of the subjects had a moderate-to-severe stroke, defined by NIH stroke severity scale, and seven patients had a large cerebral infarction. Seven serial measurements of Lp(a), total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, and other lipoproteins, major acute phase reactants and albumin levels were collected for each subject over 4 weeks. The mean initial levels, (mg/dl), of total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, Lp(a), apolipoproteins A-I and B were: 225 +/- 57.6, 154 +/- 56.0, 40 +/- 10.4, 181 +/- 93.7, 52 +/- 28.6, 130 +/- 24.6, and 141 +/- 46.1, respectively. There were no significant changes in mean serum lipid, apolipoprotein or Lp(a) levels over the 4-week study period, analyzed by a random effects model to test for time trend. In addition, there were no significant changes in established acute phase or nutritional markers (C-reactive protein, alpha 1-glycoprotein, haptoglobin or serum albumin). Our findings suggest that serum lipid, apolipoprotein and Lp(a) levels remain stable following AIS, consistent with the absence of acute phase response or nutritional deficiency.
Leisure-time physical activity and ischemic stroke risk: the Northern Manhattan Stroke Study
BACKGROUND AND PURPOSE: Physical activity reduces the risk of premature death and cardiovascular disease, but the relationship to stroke is less well studied. The objective of this study was to investigate the association between leisure-time physical activity and ischemic stroke in an urban, elderly, multiethnic population. METHODS: The Northern Manhattan Stroke Study is a population-based incidence and case-control study. Case subjects had first ischemic stroke, and control subjects were derived through random-digit dialing with 1:2 matching for age, sex, and race/ethnicity. Physical activity was recorded through a standardized in-person interview regarding the frequency and duration of 14 activities over the 2 prior weeks. Conditional logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals after adjustment for medical and socioeconomic confounders. RESULTS: Over 30 months, 369 case subjects and 678 control subjects were enrolled. Mean age was 69.9 +/- 12 years; 57% were women, 18% whites, 30% blacks, and 52% Hispanics. Leisure-time physical activity was significantly protective for stroke after adjustment for cardiac disease, peripheral vascular disease, hypertension, diabetes, smoking, alcohol use, obesity, medical reasons for limited activity, education, and season of enrollment (OR = 0.37; 95% confidence interval=0.25 to 0.55). The protective effect of physical activity was detected in both younger and older groups, in men and women, and in whites, blacks, and Hispanics. A dose-response relationship was shown for both intensity (light-moderate activity OR = 0.39; heavy OR = 0.23) and duration (<2 h/wk OR = 0.42; 2 to <5 h/wk OR = 0.35; > or =5 h/wk OR = 0.31) of physical activity. CONCLUSIONS: Leisure-time physical activity was related to a decreased occurrence of ischemic stroke in our elderly, multiethnic, urban subjects. More emphasis on physical activity in stroke prevention campaigns is needed among the elderly.
Race-ethnicity and determinants of carotid atherosclerosis in a multiethnic population. The Northern Manhattan Stroke Study
BACKGROUND AND PURPOSE: Risk factors for carotid atherosclerosis have been studied in white populations but infrequently in multiethnic cohorts. The aim of this study was to determine the importance of race-ethnicity and other factors associated with carotid atherosclerosis in a mixed population of Hispanics, blacks, and whites. METHODS: As part of the Northern Manhattan Stroke Study, 526 stroke-free community residents (aged > or = 40 years; 41% men, 59% women; 46% Hispanic, 31% black, 23% white) were recruited through random-digit dialing and had vascular risk factor evaluations. Maximum internal carotid artery plaque thickness (MICPT) was measured with B-mode ultrasound. The frequency distribution of MICPT was examined in the three race-ethnic groups, and multivariate regression was performed to identify factors that were independently associated with MICPT. RESULTS: Mean MICPT in the entire sample was 1.5 +/- 1.4 mm, increased directly with age, and was greater in whites and blacks than Hispanics. Other independent determinants of MICPT included smoking, glucose, LDL cholesterol, and hypertension. After we controlled for these covariates, Hispanic (versus non-Hispanic) race-ethnicity was still an independent determinant of less carotid plaque. There was a significant interaction between race-ethnicity and LDL cholesterol, with a greater effect of increasing LDL cholesterol among Hispanics. CONCLUSIONS: Atherosclerotic risk factors were predictive of MICPT in this mixed-ethnic cohort. Hispanics had significantly less carotid plaque after adjustment for other known risk factors, but they also had a greater impact of increasing LDL cholesterol.
Increased left atrial size as a risk factor for ischemic stroke in a multiethnic population
Dietary interventions to lower the risk of stroke
Stroke is a major cause of death and permanent disability in the USA; primary prevention and risk reduction are a critical health concern. A wealth of research investigated stroke risk factors, including primary hypertension, diabetes, and atrial fibrillation. Research has expanded to examine lifestyle factors, such as diet/dietary patterns, physical activity, cigarette smoking, and obesity distribution, as critical modifiable risk factors. Emerging evidence suggests diet/dietary patterns may lead to heightened risk of stroke. Despite a growing literature, research has yet to implement dietary interventions to explore this relationship within a US sample. This review discusses available clinical research findings reporting on the relationship among diet/dietary patterns, cardiovascular disease, and risk of stroke. We will assess challenges, limitations, and controversies, and address future research directions.
Comparison of Acute Stroke Preparedness Strategies to Decrease Emergency Department Arrival Time in a Multiethnic Cohort: The Stroke Warning Information and Faster Treatment Study
BACKGROUND AND PURPOSE: Less than 25% of stroke patients arrive to an emergency department within the 3-hour treatment window. Stroke Warning Information and Faster Treatment (SWIFT) compared an interactive intervention (II) with enhanced educational (EE) materials on recurrent stroke arrival times in a prospective cohort of multiethnic stroke/transient ischemic attack survivors. METHODS: A single-center randomized controlled trial (2005-2011) randomized participants to EE (bilingual stroke preparedness materials) or II (EE plus in-hospital sessions). We assessed differences by randomization in the proportion arriving to emergency department <3 hours, prepost intervention arrival <3 hours, incidence rate ratio for total events, and stroke knowledge and preparedness capacity. RESULTS: SWIFT randomized 1193 participants (592 EE, 601 II): mean age 63 years; 50% female, 17% black, 51% Hispanic, 26% white. At baseline, 28% arrived to emergency department <3 hours. Over 5 years, first recurrent stroke (n=133), transient ischemic attacks (n=54), or stroke mimics (n=37) were documented in 224 participants. Incidence rate ratio=1.31 (95% confidence interval=1.05-1.63; II to EE). Among II, 40% arrived <3 hours versus 46% EE (P=0.33). In prepost analysis, there was a 49% increase in the proportion arriving <3 hours (P=0.001), greatest among Hispanics (63%, P<0.003). II had greater stroke knowledge at 1 month (odds ratio=1.63; 1.23-2.15). II had higher preparedness capacity at 1 month (odds ratio=3.36; 1.86, 6.10) and 12 months (odds ratio=7.64; 2.49, 23.49). CONCLUSIONS: There was no difference in arrival <3 hours overall between II and EE; the proportion arriving <3 hours increased in both groups and in race-ethnic minorities. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00415389.
Examining Barriers and Practices to Recruitment and Retention in Stroke Clinical Trials
BACKGROUND AND PURPOSE: The National Institutes of Health policy calls for the inclusion of under-represented groups, such as women and minorities, in clinical research. Poor minority recruitment and retention in stroke clinical trials remain a significant challenge limiting safety and efficacy in a general population. Previous research examines participant barriers to clinical trial involvement, but little is known about the investigator perspective. This study addresses this gap and examines researcher-reported barriers and best practices of minority involvement in stroke clinical trials. METHODS: Quantitative and qualitative methods, including surveys, focus groups, and key informant interviews were used. RESULTS: In a survey of 93 prominent stroke researchers, 43 (51.2%; 70% response rate) respondents reported proactively setting recruitment goals for minority inclusion, 29 respondents (36.3%) reported requiring cultural competency staff training, and 44 respondents (51.2%) reported using community consultation about trial design. Focus groups and key informant interviews highlighted structural and institutional challenges to recruitment of minorities, including mistrust of the research/medical enterprise, poor communication, and lack of understanding of clinical trials. Researcher-identified best practices included using standardized project management procedures and protocols (eg, realistic budgeting to support challenges in recruitment, such as travel/parking reimbursement for participants), research staff cultural competency and communication training, and developing and fostering community partnerships that guide the research process. CONCLUSIONS: This study's formative evaluation contributes a new dimension to the literature as it highlights researcher-reported barriers and best practices for enhancing participation of minority populations into stroke clinical trials.
Discharge educational strategies for reduction of vascular events (DESERVE): design and methods
RATIONALE: Stroke and vascular risk factors disproportionately affect minority populations, with Blacks and Hispanics experiencing a 2.5- and 2.0-fold greater risk compared with whites, respectively. Patients with transient ischemic attacks and mild, nondisabling strokes tend to have short hospital stays, rapid discharges, and inaccurate perceptions of vascular risk. AIM: The primary aim of the Discharge Educational Strategies for Reduction of Vascular Events (DESERVE) trial is to evaluate the efficacy of a novel community health worker-based multilevel discharge intervention vs. standard discharge care on vascular risk reduction among racially/ethnically diverse transient ischemic attack/mild stroke patients at one-year postdischarge. We hypothesize that those randomized to the discharge intervention will have reduced modifiable vascular risk factors as determined by systolic blood pressure compared with those receiving usual care. SAMPLE SIZE ESTIMATES: Given 300 subjects per group and alpha of 0.05, the power to detect a 6 mmHg reduction in systolic blood pressure is 89%. DESIGN: DESERVE trial is a prospective, randomized, multicenter clinical trial of a novel discharge behavioral intervention. Patients with transient ischemic attack/mild stroke are randomized during hospitalization or emergency room visit to intervention or usual care. Intervention begins prior to discharge and continues postdischarge. STUDY OUTCOMES: The primary outcome is difference in systolic blood pressure reduction between groups at 12 months. Secondary outcomes include between-group differences in change in glycated hemoglobin, smoking rates, medication adherence, and recurrent stroke/transient ischemic attack at 12 months. DISCUSSION: DESERVE will evaluate whether a novel discharge education strategy leads to improved risk factor control in a racially diverse population.
Itemized NIHSS subsets predict positive MRI strokes in patients with mild deficits
BACKGROUND: While imaging is useful in confirming the diagnosis of ischemic stroke, negative diffusion weighted imaging (DWI) is reported in up to 25% of patients. Our aim was to identify predictors of MRI-positive stroke from the itemized NIHSS. METHODS: Data were derived from the Stroke Warning Information and Faster Treatment study from February 2006 to February 2010 among patients with mild deficits (NIHSS 0-5) and a final diagnosis of stroke by a vascular neurologist. All MRI sequences were reviewed for the presence or absence of an acute infarct on DWI. Multivariate logistic regression assessed factors predicting DWI-positive strokes; p<0.05 was considered significant. RESULTS: 894 patients had a discharge diagnosis of stroke; 709 underwent MRI and 28.0% were DWI negative. All patients with visual field deficits or neglect were DWI positive. On multivariate analysis including total NIHSS (0-2 vs. 3-5) and itemized NIHSS score subsets, predictors of a positive DWI were NIHSS score of 3-5 (OR=3.3, 95% CI: 1.8-6.1), motor deficits (OR=1.7, 95% CI: 1.1-2.8), ataxia (OR=1.9, 95% CI: 1.0-3.5), and absence of sensory deficits (OR=1.7, 95% CI: 1.0-2.7). We developed the NIHSS-m score that predicts DWI positivity in patients with mild deficits in the absence of neglect or visual field deficits. CONCLUSION: NIHSS score subsets predict DWI positivity in mild strokes. The presence of neglect or visual field deficits on the NIHSS subsets is most likely to have an MRI correlate even in patients with low NIHSS.
Race/ethnic Differences in Post-stroke Depression (PSD): Findings from the Stroke Warning Information and Faster Treatment (SWIFT) Study
OBJECTIVE: Post-stroke depression (PSD) is common and associated with poor stroke outcomes, but few studies have examined race/ethnic disparities in PSD. Given the paucity of work and inconsistent findings in this important area of research, our study aimed to examine race/ethnic differences in depression in a multi-ethnic cohort of stroke patients. DESIGN: Longitudinal. SETTING: Prospective trial of a post-stroke educational intervention. PARTICIPANTS: 1,193 mild/moderate ischemic stroke/transient ischemic attack (TIA) patients. MAIN OUTCOME MEASURES: We used the Center for Epidemiologic Studies Depression (CES-D) Scale to assess subthreshold (CES-D score 8-15) and full (CES-D score >/= 16) depression at one month ("early") and 12 months ("late") following stroke. Multinomial logistic regression analyses examined the association between race/ethnicity and early and late PSD separately. RESULTS: The prevalence of subthreshold and full PSD was 22.5% and 32.6% in the early period and 22.0% and 27.4% in the late period, respectively. Hispanics had 60% lower odds of early full PSD compared with non-Hispanic Whites after adjusting for other covariates (OR=.4, 95% CI: .2, .8). Race/ethnicity was not significantly associated with late PSD. CONCLUSIONS: Hispanic stroke patients had half the odds of PSD in early period compared with Whites, but no difference was found in the later period. Further studies comparing trajectories of PSD between race/ethnic groups may further our understanding of race/ethnic disparities in PSD and help identify effective interventions.
The Association Between Online Health Information-Seeking Behaviors and Health Behaviors Among Hispanics in New York City: A Community-Based Cross-Sectional Study
BACKGROUND: Hispanics are the fastest-growing minority group in the United States and they suffer from a disproportionate burden of chronic diseases. Studies have shown that online health information has the potential to affect health behaviors and influence management of chronic disease for a significant proportion of the population, but little research has focused on Hispanics. OBJECTIVE: The specific aim of this descriptive, cross-sectional study was to examine the association between online health information-seeking behaviors and health behaviors (physical activity, fruit and vegetable consumption, alcohol use, and hypertension medication adherence) among Hispanics. METHODS: Data were collected from a convenience sample (N=2680) of Hispanics living in northern Manhattan by bilingual community health workers in a face-to-face interview and analyzed using linear and ordinal logistic regression. Variable selection and statistical analyses were guided by the Integrative Model of eHealth Use. RESULTS: Only 7.38% (198/2680) of the sample reported online health information-seeking behaviors. Levels of moderate physical activity and fruit, vegetable, and alcohol consumption were low. Among individuals taking hypertension medication (n=825), adherence was reported as high by approximately one-third (30.9%, 255/825) of the sample. Controlling for demographic, situational, and literacy variables, online health information-seeking behaviors were significantly associated with fruit (beta=0.35, 95% CI 0.08-0.62, P=.01) and vegetable (beta=0.36, 95% CI 0.06-0.65, P=.02) consumption and physical activity (beta=3.73, 95% CI 1.99-5.46, P<.001), but not alcohol consumption or hypertension medication adherence. In the regression models, literacy factors, which were used as control variables, were associated with 3 health behaviors: social networking site membership (used to measure one dimension of computer literacy) was associated with fruit consumption (beta=0.23, 95% CI 0.05-0.42, P=.02), health literacy was associated with alcohol consumption (beta=0.44, 95% CI 0.24-0.63, P<.001), and hypertension medication adherence (beta=-0.32, 95% CI -0.62 to -0.03, P=.03). Models explained only a small amount of the variance in health behaviors. CONCLUSIONS: Given the promising, although modest, associations between online health information-seeking behaviors and some health behaviors, efforts are needed to improve Hispanics' ability to access and understand health information and to enhance the availability of online health information that is suitable in terms of language, readability level, and cultural relevance.