Ethnic differences in stroke mortality between non-Hispanic whites, Hispanic whites, and blacks. The National Longitudinal Mortality Study

Prevalence and predictors of stroke among individuals with prediabetes and diabetes in Florida

Background

The prevalence of both prediabetes and diabetes have been increasing in Florida. These increasing trends will likely result in increases of stroke burden since both conditions are major risk factors of stroke. However, not much is known about the prevalence and predictors of stroke among adults with prediabetes and diabetes and yet this information is critical for guiding health programs aimed at reducing stroke burden. Therefore, the objectives of this study were to estimate the prevalence and identify predictors of stroke among persons with either prediabetes or diabetes in Florida.

Methods

The 2019 Behavioral Risk Factor Surveillance System (BRFSS) survey data were obtained from the Florida Department of Health and used for the study. Weighted prevalence estimates of stroke and potential predictor variables as well as their 95% confidence intervals were computed for adults with prediabetes and diabetes. A conceptual model of predictors of stroke among adults with prediabetes and diabetes was constructed to guide statistical model building. Two multivariable logistic models were built to investigate predictors of stroke among adults with prediabetes and diabetes.

Results

The prevalence of stroke among respondents with prediabetes and diabetes were 7.8% and 11.2%, respectively. The odds of stroke were significantly (p ≤ 0.05) higher among respondents with prediabetes that were ≥ 45 years old (Odds ratio [OR] = 2.82; 95% Confidence Interval [CI] = 0.74, 10.69), had hypertension (OR = 5.86; CI = 2.90, 11.84) and hypercholesterolemia (OR = 3.93; CI = 1.84, 8.40). On the other hand, the odds of stroke among respondents with diabetes were significantly (p ≤ 0.05) higher if respondents were non-Hispanic Black (OR = 1.79; CI = 1.01, 3.19), hypertensive (OR = 3.56; CI = 1.87, 6.78) and had depression (OR = 2.02; CI = 1.14, 3.59).

Conclusions

Stroke prevalence in Florida is higher among adults with prediabetes and diabetes than the general population of the state. There is evidence of differences in the importance of predictors of stroke among populations with prediabetes and those with diabetes. These findings are useful for guiding health programs geared towards reducing stroke burden among populations with prediabetes and diabetes.

Adherence to Acute Care Measures Affects Mortality in Patients with Ischemic Stroke: The Florida Stroke Registry

OBJECTIVES

How race/ethnic disparities in acute stroke care contribute to disparities in outcomes is not well-understood. We examined the relationship between acute stroke care measures with mortality within the first year and 30-day hospital readmission by race/ethnicity.

MATERIALS AND METHODS

The study included fee-for-service Medicare beneficiaries age ≥65 with ischemic stroke in 2010-2013 treated at 66 hospitals in the Florida Stroke Registry. Stroke care metrics included intravenous Alteplase treatment, in-hospital antithrombotic therapy, DVT prophylaxis, discharge antithrombotic therapy, anticoagulation therapy, statin use, and smoking cessation counseling. We used mixed logistic models to assess the associations between stroke care and mortality (in-hospital, 30-day, 6-month, 1-year post-stroke) and hospital readmission by race/ethnicity, adjusting for demographics, stroke severity, and vascular risk factors.

RESULTS

Among 14,100 ischemic stroke patients in the full study population (73% white, 11% Black, 15% Hispanic), mortality was 3% in-hospital, 12% at 30d, 21% at 6m, 26% at 1y, and 15% had a hospital readmission within 30 days. Patients who received antithrombotics early and at discharge had lower mortality at all time points, and the protective association for early antithrombotic use was strongest among whites. Eligible patients who received statin therapy at discharge had decreased 6m and 1y mortality, but specifically among minority groups. Statin therapy was associated with lower 30-day hospital readmission.

CONCLUSIONS

Acute stroke care measures, particularly antithrombotic use and statin therapy, were associated with reduced odds of long-term mortality. The benefits of these acute care measures were less likely among Hispanic patients. Results underscore the importance of optimizing acute stroke care for all patients.

Challenge and Yield of Enrolling Racially and Ethnically Diverse Patient Populations in Low Event Rate Clinical Trials

BACKGROUND AND PURPOSE

We report patient enrollment and retention by race and ethnicity in the CREST (Carotid Revascularization Endarterectomy Versus Stent Trial) and assess potential effect modification by race/ethnicity. In addition, we discuss the challenge of detecting differences in study outcomes when subgroups are small and the event rate is low.

METHODS

We compared 2502 patients by race, ethnicity, baseline characteristics, and primary outcome (any periprocedural stroke, death, or myocardial infarction and subsequent ipsilateral stroke up to 10 years).

RESULTS

Two hundred forty (9.7%) patients were minority by race (6.1%) or ethnicity (3.6%); 109 patients (4.4%) were black, 32 (1.3%) Asian, 2332 (93.4%) white, 11 (0.4%) other, and 18 (0.7%) unknown. Ninety (3.6%) were Hispanic, 2377 (95%) non-Hispanic, and 35 (1.4%) unknown. The rate of the primary end point for all patients was 10.9%±0.9% at 10 years and did not differ by race or ethnicity (P_inter>0.24).

CONCLUSIONS

The proportion of minorities recruited to CREST was below their representation in the general population, and retention of minority patients was lower than for whites. Primary outcomes did not differ by race or ethnicity. However, in CREST (like other studies), the lack of evidence of a racial/ethnic difference in the treatment effect should be interpreted with caution because of low statistical power to detect such a difference.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00004732.

Controversies and evidence for cardiovascular disease in the diverse Hispanic population

OBJECTIVE

Hispanics account for approximately 17% of the U.S.

POPULATION

They are one of the fastest growing racial/ethnic groups, second only to Asians. This heterogeneous population has diverse socioeconomic conditions, making the prevention, diagnosis, and management of vascular disease difficult. This paper discusses the cultural, racial, and social aspects of the Hispanic community in the United States and assesses how they affect vascular disease within this population. Furthermore, it explores risk factors, medical and surgical treatments, and outcomes of vascular disease in the Hispanic population; generational evolution of these conditions; and the phenomenon called the Hispanic paradox.

METHODS

A systematic search of the literature was performed to identify all English-language publications from 1991 to 2014 using PubMed, which draws from the National Institutes of Health and U.S. National Library of Medicine, with the words "cardiovascular disease," "prevalence," "vascular," and "Hispanic." An additional search was performed using "cardiovascular disease and Mexico," "cardiovascular disease and Cuba," "cardiovascular disease and Puerto Rico," and "cardiovascular disease and Latin America" as well as for complications, management, outcomes, surgery, vascular disease, and Hispanic paradox. The resulting publications were queried for generational data (spanning multiple well-defined age groups) regarding cardiovascular disease, and cross-references were obtained from their bibliographies. Results are segmented by country of origin.

RESULTS

Compared with non-Hispanic whites, Hispanics face higher risks of cardiovascular diseases because of a high prevalence of high blood pressure, obesity, diabetes mellitus, and ischemic stroke. However, the incidence of peripheral arterial disease and carotid disease appears to be significantly lower than in whites. The Hispanic paradox (lower mortality in spite of higher cardiovascular risk factors) may relate to challenges in ascribing life expectancy and cause of death in this diverse population. Low socioeconomic status and high prevalence of concomitant diseases negatively influence the outcomes of all patients, independent of being Hispanic.

CONCLUSIONS

Understanding the cultural diversity in Hispanics is important in terms of targeting preventive measures to modify cardiovascular risk factors, which affect development and outcomes of vascular disease. The available literature regarding vascular disease in the Hispanic population is limited, and further longitudinal study is warranted to improve health care delivery and outcomes in this group.

Cardiovascular risk status of Afro-origin populations across the spectrum of economic development: findings from the Modeling the Epidemiologic Transition Study

BACKGROUND

Cardiovascular risk factors are increasing in most developing countries. To date, however, very little standardized data has been collected on the primary risk factors across the spectrum of economic development. Data are particularly sparse from Africa.

METHODS

In the Modeling the Epidemiologic Transition Study (METS) we examined population-based samples of men and women, ages 25-45 of African ancestry in metropolitan Chicago, Kingston, Jamaica, rural Ghana, Cape Town, South Africa, and the Seychelles. Key measures of cardiovascular disease risk are described.

RESULTS

The risk factor profile varied widely in both total summary estimates of cardiovascular risk and in the magnitude of component factors. Hypertension ranged from 7% in women from Ghana to 35% in US men. Total cholesterol was well under 200 mg/dl for all groups, with a mean of 155 mg/dl among men in Ghana, South Africa and Jamaica. Among women total cholesterol values varied relatively little by country, following between 160 and 178 mg/dl for all 5 groups. Levels of HDL-C were virtually identical in men and women from all study sites. Obesity ranged from 64% among women in the US to 2% among Ghanaian men, with a roughly corresponding trend in diabetes. Based on the Framingham risk score a clear trend toward higher total risk in association with socioeconomic development was observed among men, while among women there was considerable overlap, with the US participants having only a modestly higher risk score.

CONCLUSIONS

These data provide a comprehensive estimate of cardiovascular risk across a range of countries at differing stages of social and economic development and demonstrate the heterogeneity in the character and degree of emerging cardiovascular risk. Severe hypercholesterolemia, as characteristic in the US and much of Western Europe at the onset of the coronary epidemic, is unlikely to be a feature of the cardiovascular risk profile in these countries in the foreseeable future, suggesting that stroke may remain the dominant cardiovascular event.

Statistical evaluation of adding multiple risk factors improves Framingham stroke risk score

BACKGROUND

Framingham Stroke Risk Score (FSRS) is the most well-regarded risk appraisal tools for evaluating an individual's absolute risk on stroke onset. However, several widely accepted risk factors for stroke were not included in the original Framingham model. This study proposed a new model which combines an existing risk models with new risk factors using synthesis analysis, and applied it to the longitudinal Atherosclerosis Risk in Communities (ARIC) data set.

METHODS

Risk factors in original prediction models and new risk factors in proposed model had been discussed. Three measures, like discrimination, calibration and reclassification, were used to evaluate the performance of the original Framingham model and new risk prediction model.

RESULTS

Modified C-statistics, Hosmer-Lemeshow Test and classless NRI, class NRI were the statistical indices which, respectively, denoted the performance of discrimination, calibration and reclassification for evaluating the newly developed risk prediction model on stroke onset. It showed that the NEW-STROKE (new stroke risk score prediction model) model had higher modified C-statistics, smaller Hosmer-Lemeshow chi-square values after recalibration than original FSRS model, and the classless NRI and class NRI of the NEW-STROKE model over the original FSRS model were all significantly positive in overall group.

CONCLUSION

The NEW-STROKE integrated with seven literature-derived risk factors outperformed the original FSRS model in predicting the risk score of stroke. It illustrated that seven literature-derived risk factors contributed significantly to stroke risk prediction.

Stroke Risk Factors, Genetics, and Prevention

Stroke is a heterogeneous syndrome, and determining risk factors and treatment depends on the specific pathogenesis of stroke. Risk factors for stroke can be categorized as modifiable and nonmodifiable. Age, sex, and race/ethnicity are nonmodifiable risk factors for both ischemic and hemorrhagic stroke, while hypertension, smoking, diet, and physical inactivity are among some of the more commonly reported modifiable risk factors. More recently described risk factors and triggers of stroke include inflammatory disorders, infection, pollution, and cardiac atrial disorders independent of atrial fibrillation. Single-gene disorders may cause rare, hereditary disorders for which stroke is a primary manifestation. Recent research also suggests that common and rare genetic polymorphisms can influence risk of more common causes of stroke, due to both other risk factors and specific stroke mechanisms, such as atrial fibrillation. Genetic factors, particularly those with environmental interactions, may be more modifiable than previously recognized. Stroke prevention has generally focused on modifiable risk factors. Lifestyle and behavioral modification, such as dietary changes or smoking cessation, not only reduces stroke risk, but also reduces the risk of other cardiovascular diseases. Other prevention strategies include identifying and treating medical conditions, such as hypertension and diabetes, that increase stroke risk. Recent research into risk factors and genetics of stroke has not only identified those at risk for stroke but also identified ways to target at-risk populations for stroke prevention.

High-risk carotid plaques identified by CT-angiogram can predict acute myocardial infarction

Prior studies identified the incremental value of non-invasive imaging by CT-angiogram (CTA) to detect high-risk coronary atherosclerotic plaques. Due to their superficial locations, larger calibers and motion-free imaging, the carotid arteries provide the best anatomic access for the non-invasive characterization of atherosclerotic plaques. We aim to assess the ability of predicting obstructive coronary artery disease (CAD) or acute myocardial infarction (MI) based on high-risk carotid plaque features identified by CTA. We retrospectively examined carotid CTAs of 492 patients that presented with acute stroke to characterize the atherosclerotic plaques of the carotid arteries and examined development of acute MI and obstructive CAD within 12-months. Carotid lesions were defined in terms of calcifications (large or speckled), presence of low-attenuation plaques, positive remodeling, and presence of napkin ring sign. Adjusted relative risks were calculated for each plaque features. Patients with speckled (<3 mm) calcifications and/or larger calcifications on CTA had a higher risk of developing an MI and/or obstructive CAD within 1 year compared to patients without (adjusted RR of 7.51, 95%CI 1.26-73.42, P = 0.001). Patients with low-attenuation plaques on CTA had a higher risk of developing an MI and/or obstructive CAD within 1 year than patients without (adjusted RR of 2.73, 95%CI 1.19-8.50, P = 0.021). Presence of carotid calcifications and low-attenuation plaques also portended higher sensitivity (100 and 79.17%, respectively) for the development of acute MI. Presence of carotid calcifications and low-attenuation plaques can predict the risk of developing acute MI and/or obstructive CAD within 12-months. Given their high sensitivity, their absence can reliably exclude 12-month events.

Dietary fried fish intake increases risk of CVD: the REasons for Geographic And Racial Differences in Stroke (REGARDS) study

OBJECTIVE

The objective of the present study was to examine the relationship of dietary fried fish consumption and risk of cardiovascular events and all-cause mortality.

DESIGN

Prospective cohort study among participants of the REasons for Geographic And Racial Differences in Stroke (REGARDS) study who resided in the USA.

SETTING

The primary outcome measures included the hazard ratios (HR) of incident CVD including first incident fatal or non-fatal ischaemic stroke or myocardial infarction and all-cause mortality, based on cumulative average fish consumption ascertained at baseline.

SUBJECTS

Participants (n 16 479) were enrolled between 2003 and 2007, completed the self-administered Block98 FFQ and were free of CVD at baseline.

RESULTS

There were 700 cardiovascular events over a mean follow-up of 5·1 years. After adjustment for sociodemographic variables, health behaviours and other CVD risk factors, participants eating ≥2 servings fried fish/week (v. <1 serving/month) were at a significantly increased risk of cardiovascular events (HR=1·63; 95 % CI 1·11, 2·40). Intake of non-fried fish was not associated with risk of incident CVD. There was no association found with dietary fried or non-fried fish intake and cardiovascular or all-cause mortality.

CONCLUSIONS

Fried fish intake of two or more servings per week is associated with an increased risk of cardiovascular events. Given the increased intake of fried fish in the stroke belt and among African Americans, these data suggest that dietary fried fish intake may contribute to geographic and racial disparities in CVD.

Linkages to improve mortality data for American Indians and Alaska Natives: a new model for death reporting?

Racial misclassification is a well-documented weakness of mortality data taken from death certificates. As a result, mortality statistics for American Indians and Alaska Natives (AI/ANs) present, at best, an inaccurate and misleading assessment of mortality in this population. Studies evaluating the quality of race/ethnicity reporting on death certificates have linked data from death certificates to other data sources collected when the decedent was still alive (e.g., Census, Current Population Survey). Such studies have shown substantial misclassification of AI/AN decedents. Despite limitations, linking mortality data from death certificates with data from other sources collected when decedents were living provides opportunities to evaluate and correct misclassification of populations such as AI/AN persons and facilitates the calculation and presentation of more accurate mortality statistics.

African Caribbeans have greater subclinical cerebrovascular disease than Europeans: this is associated with both their elevated resting and ambulatory blood pressure and their hyperglycaemia

OBJECTIVES

Stroke is elevated in people of black African descent, but evidence for excess subclinical cerebrovascular disease is conflicting, and the role of risk factors in determining any ethnic differences observed unexplored.

METHODS

We compared prevalence of brain infarcts, and severe white matter hyperintensities (WMHs) on cerebral MRI, in a community-based sample of men and women aged 58-86 of African Caribbean (214) and European (605) descent, in London, UK. Resting, central and ambulatory blood pressure (BP) were measured; diabetes was assessed by blood testing and questionnaire.

RESULTS

Mean age was 70. Multiple (≥4) brain infarcts and severe WMH occurred more frequently in African Caribbeans (18/43%), than Europeans (7/33%, P=0.05/0.008). Separately, clinic and night-time ambulatory BP were significantly associated with severe WMH in both ethnic groups; when both were entered into the model, the association for clinic SBP was attenuated and lost statistical significance [1.00 (0.98-1.02) P=0.9 in Europeans, 1.00 (0.97-1.04) P=0.9 in African Caribbeans], whereas the association for night-time SBP was retained [1.04 (1.02-1.07) P<0.001 in Europeans, 1.08 (1.03-1.12), P=0.001 in African Caribbeans]. The greater age-adjusted and sex-adjusted risk of severe WMH in African Caribbeans compared with Europeans [2.08 (1.15-3.76) P=0.02], was attenuated to 1.45 [(0.74-2.83) P=0.3] on adjustment for clinic and night-time systolic pressure, antihypertensive medication use and glycated haemoglobin.

CONCLUSION

African Caribbeans have a greater burden of subclinical cerebrovascular disease than Europeans. This excess is related to elevated clinic and ambulatory BP, and to hyperglycaemia.

Age differences in the associations of behavioral and psychosocial factors with stroke

BACKGROUND

Stroke remains a major public health burden. Few studies have focused on the age differences in the associations of behavioral and psychosocial factors with stroke while no study focusing on the effect of severe psychological distress (SPD) on stroke has been conducted. The aim of this study was to examine the age differences in these risk factors for stroke as young (18-44 years), middle aged (45-64 years), and elderly (65 years or older).

METHODS

A total of 1,258 adults with stroke and 39,985 controls were selected from the 2005 California Health Interview Survey. Multiple logistic regression analyses were used to estimate the associations of the factors with stroke at different ages.

RESULTS

The prevalence of SPD was 10% in cases and 3.6% in controls, respectively. Overall, current smoking, lack of physical activity, alcohol consumption, SPD, type II diabetes, male, older age, and unemployment were all associated with a higher prevalence of stroke. Practically, we found that smoking and SPD were associated with the prevalence of stroke in young adults, lack of physical activity was associated with the prevalence of stroke in middle-aged adults, and lack of physical activity and SPD were associated with the prevalence of stroke in the elderly.

CONCLUSIONS

Appropriate intervention for reducing stroke and eliminating its disparities may be developed separately at each age.

Racial differences in the impact of elevated systolic blood pressure on stroke risk

BACKGROUND

Between the ages 45 and 65 years, incident stroke is 2 to 3 times more common in blacks than in whites, a difference not explained by traditional stroke risk factors.

METHODS

Stroke risk was assessed in 27 748 black and white participants recruited between 2003 and 2007, who were followed up through 2011, in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study. Racial differences in the impact of systolic blood pressure (SBP) was assessed using proportional hazards models. Racial differences in stroke risk were assessed in strata defined by age (<65 years, 65-74 years, and ≥75 years) and SBP (<120 mm Hg, 120-139 mm Hg, and 140-159 mm Hg).

RESULTS

Over 4.5 years of follow-up, 715 incident strokes occurred. A 10-mm Hg difference in SBP was associated with an 8% (95% CI, 0%-16%) increase in stroke risk for whites, but a 24% (95% CI, 14%-35%) increase for blacks (P value for interaction, .02). For participants aged 45 to 64 years (where disparities are greatest), the black to white hazard ratio was 0.87 (95% CI, 0.48-1.57) for normotensive participants, 1.38 (95% CI, 0.94-2.02) for those with prehypertension, and 2.38 (95% CI, 1.19-4.72) for those with stage 1 hypertension.

CONCLUSIONS

These findings suggest racial differences in the impact of elevated blood pressure on stroke risk. When these racial differences are coupled with the previously documented higher prevalence of hypertension and poorer control of hypertension in blacks, they may account for much of the racial disparity in stroke risk.

Racial differences in albuminuria, kidney function, and risk of stroke

BACKGROUND

The objective of this study was to examine the joint associations of estimated glomerular filtration rate (eGFR) and urinary albumin excretion with incident stroke in a large national cohort study.

METHODS

Associations of urinary albumin to creatinine ratio (ACR) and eGFR with incident stroke were examined in 25,310 participants of the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a prospective study of black and white US adults ≥45 years of age.

RESULTS

A total of 548 incident strokes were observed over a median of 4.7 years of follow-up. Higher ACR values were associated with lower stroke-free survival in both black and white participants. Among black participants, as compared to an ACR <10 mg/g, the hazard ratios of stroke associated with an ACR of 10-29.99, 30-300, and >300 mg/g were 1.41 (95% confidence interval [CI] 1.01-1.98), 2.10 (95% CI 1.48-2.99), and 2.70 (95% CI 1.58-4.61), respectively, in analyses adjusted for traditional stroke risk factors and eGFR. In contrast, the hazard ratios among white subjects were only modestly elevated and not statistically significant after adjustment for established stroke risk factors. eGFR <60 mL/min/1.73 m(2) was not associated with incident stroke in black or white participants after adjustment for established stroke risk factors.

CONCLUSIONS

Higher ACR was independently associated with higher risk of stroke in black but not white participants from a national cohort. Elucidating the reasons for these findings may uncover novel mechanisms for persistent racial disparities in stroke.

Stroke incidence in older US Hispanics: is foreign birth protective?

BACKGROUND AND PURPOSE

Although Hispanics are the fastest growing ethnic group in the United States, relatively little is known about stroke risk in US Hispanics. We compare stroke incidence and socioeconomic predictors in US- and foreign-born Hispanics with patterns among non-Hispanic whites.

METHODS

Health and Retirement Study participants aged 50+ years free of stroke in 1998 (mean baseline age, 66.3 years) were followed through 2008 for self- or proxy-reported first stroke (n=15 784; 1388 events). We used discrete-time survival analysis to compare stroke incidence among US-born (including those who immigrated before age 7 years) and foreign-born Hispanics with incidence in non-Hispanic whites. We also examined childhood and adult socioeconomic characteristics as predictors of stroke among Hispanics, comparing effect estimates with those for non-Hispanic whites.

RESULTS

In age- and sex-adjusted models, US-born Hispanics had higher odds of stroke onset than non-Hispanic whites (OR, 1.44; 95% CI, 1.08-1.90), but these differences were attenuated and nonsignificant in models that controlled for childhood and adulthood socioeconomic factors (OR, 1.07; 95% CI, 0.80-1.42). In contrast, in models adjusted for all demographic and socioeconomic factors, foreign-born Hispanics had significantly lower stroke risk than non-Hispanic whites (OR, 0.58; 95% CI, 0.41-0.81). The impact of socioeconomic predictors on stroke did not differ between Hispanics and whites.

CONCLUSIONS

In this longitudinal national cohort, foreign-born Hispanics had lower incidence of stroke incidence than non-Hispanic whites and US-born Hispanics. Findings suggest that foreign-born Hispanics may have a risk factor profile that protects them from stroke as compared with other Americans.

Traditional risk factors as the underlying cause of racial disparities in stroke: lessons from the half-full (empty?) glass

BACKGROUND AND PURPOSE

Black/white disparities in stroke incidence are well documented, but few studies have assessed the contributions to the disparity. Here we assess the contribution of "traditional" risk factors.

METHODS

A total of 25 714 black and white men and women, aged≥45 years and stroke-free at baseline, were followed for an average of 4.4 years to detect stroke. Mediation analysis using proportional hazards analysis assessed the contribution of traditional risk factors to racial disparities.

RESULTS

At age 45 years, incident stroke risk was 2.90 (95% CI: 1.72-4.89) times more likely in blacks than in whites and 1.66 (95% CI: 1.34-2.07) times at age 65 years. Adjustment for risk factors attenuated these excesses by 40% and 45%, respectively, resulting in relative risks of 2.14 (95% CI: 1.25-3.67) and 1.35 (95% CI: 1.08-1.71). Approximately one half of this mediation is attributable to systolic blood pressure. Further adjustment for socioeconomic factors resulted in total mediation of 47% and 53% to relative risks of 2.01 (95% CI: 1.16-3.47) and 1.30 (1.03-1.65), respectively.

CONCLUSIONS

Between ages 45 to 65 years, approximately half of the racial disparity in stroke risk is attributable to traditional risk factors (primarily systolic blood pressure) and socioeconomic factors, suggesting a critical need to understand the disparity in the development of these traditional risk factors. Because half of the excess stroke risk in blacks is not attributable to traditional risk factors and socioeconomic factors, differential impact of risk factors, residual confounding, or nontraditional risk factors may also play a role.

Ethnic differences in carotid artery diameter and stiffness: the Northern Manhattan Study

OBJECTIVE

Race/ethnic differences in carotid arterial function and structure exist among those with cerebrovascular disease, but whether differences persist among healthy populations is unknown. Our objective was to investigate differences in carotid artery diameter and stiffness between race/ethnic groups, and examine whether these race/ethnic differences were age-dependent.

METHODS

Carotid diameters were assessed by B-mode ultrasound among 1536 participants from the Northern Manhattan Study (NOMAS), and carotid stiffness metrics were calculated. We used multivariable linear regression models to determine the relationship between race/ethnicity and both carotid arterial stiffness and carotid diastolic diameter.

RESULTS

Mean participant age was 70 ± 9 years (Hispanics = 68 ± 8, blacks = 72 ± 9, and whites = 74 ± 9, p < 0.0001). Mean DDIAM was 6.2 ± 1.0mm (Hispanics = 6.2 ± 0.9 mm, blacks = 6.3 ± 1.0 mm, and whites = 6.3 ± 1.0 mm, p < 0.005) and mean STIFF was 8.7 ± 6.3 (Hispanics = 8.5 ± 5.7, blacks = 9.2 ± 6.2 and whites = 8.9 ± 6.9, p < 0.02). In a model that adjusted for sociodemographics and vascular risk factors including hypertension, diabetes, dislipidemia, renal function, physical acticity and a history of known coronary artery diseases; age was positively associated with greater DDIAM in Hispanics (p < 0.0001) but not among blacks or whites. Older age was associated with greater stiffness among Hispanics (p < 0.0001) and blacks (p < 0.003), but not among whites.

CONCLUSIONS

We found race/ethnic differences in the association between age and arterial stiffness and diameter, including age-dependent arterial dilation observed in Hispanics that was not observed among blacks or whites.

Racial and geographic differences in prevalence, awareness, treatment and control of dyslipidemia: the reasons for geographic and racial differences in stroke (REGARDS) study

BACKGROUND/AIMS

There are racial and geographic disparities in stroke mortality, with higher rates among African Americans (AAs) and those living in the southeastern US ('stroke belt'). Racial and geographic differences in dyslipidemia prevalence, awareness, treatment and control may, in part, account for the observed disparities in stroke mortality.

METHODS

Reasons for Geographic and Racial Differences in Stroke (REGARDS) is a national observational study of community-dwelling black and white participants aged 45 and older, with oversampling from the stroke belt. As of January 15, 2007, 26,122 participants were enrolled and a fasting lipid panel was available of 21,068. Awareness, treatment and control of dyslipidemia were estimated overall and compared across race-sex-region strata.

RESULTS

There were 55% of the participants with dyslipidemia and no racial differences in prevalence. Adjusting for demographic and established stroke risk factors, AAs had a lower prevalence (OR 0.74; 95% CI: 0.66, 0.77) and were less likely to be aware (0.69; 0.61, 0.78), treated (0.77; 0.67, 0.89) and controlled (0.67; 0.58, 0.77) than whites. There was lower control outside of the stroke belt (0.87; 0.76, 0.99).

CONCLUSION

Racial, but not geographic, differences in dyslipidemia management may play a role in the excess stroke burden in the Southeast.

Special considerations on the management of Latino patients with type 2 diabetes mellitus

BACKGROUND

Latinos are the largest minority population in the United States, and are characterized by higher rates of obesity and diabetes compared to Whites. The prevalence of diagnosed diabetes in Latinos is two-fold higher than in Caucasians, and Latinos suffer from higher rates of diabetic complications and mortality. As the diabetes epidemic continues to expand and exert greater socioeconomic strain on national healthcare systems, the success of global and national healthcare initiatives for diabetes prevention and improvement of care will depend upon strategies targeted specifically toward this population. Essential to such strategies is an understanding of success factors unique to the Latino population for diabetes prevention and achievement of optimal treatment outcomes.

METHODS

A PubMed search was conducted for literature describing type 2 diabetes and its complications in Latinos. Specifically, we sought data describing epidemiology, disparities, management considerations, and success factors in this population.

RESULTS

The title search yielded more than 2000 articles, 80 of which were deemed directly relevant to this review. The inherent limitations of this subjective selection process are acknowledged.

CONCLUSIONS

A number of studies have highlighted various ethnic disparities in Latinos with diabetes including higher HbA1c levels, greater rates of obesity and metabolic syndrome, and a larger proportion of individuals with inadequate access to care. While relatively fewer studies describe success factors for redressing cultural disparities in diabetes, the current body of literature supports primary care strategies aimed at effective provider-patient relationships and culturally tailored education and lifestyle modification regimens. Further research demonstrating effective, culturally tailored practices that are suitable to the primary care setting would be of value to providers treating Latinos with diabetes.

Disparities in stroke incidence contributing to disparities in stroke mortality

OBJECTIVE

While black-white and regional disparities in U.S. stroke mortality rates are well documented, the contribution of disparities in stroke incidence is unknown. We provide national estimates of stroke incidence by race and region, contrasting these to publicly available stroke mortality data.

METHODS

This analysis included 27,744 men and women without prevalent stroke (40.4% black), aged ≥45 years from the REasons for Geographic And Racial Differences in Stroke (REGARDS) national cohort study, enrolled 2003-2007. Incident stroke was defined as first occurrence of stroke over 4.4 years of follow-up. Age-sex-adjusted stroke mortality rates were calculated using data from the Centers for Disease Control and Prevention (CDC) Wide-Ranging Online Data for Epidemiological Research (WONDER) System.

RESULTS

There were 460 incident strokes over 113,469 person-years of follow-up. Relative to the rest of the United States, incidence rate ratios (IRRs) of stroke in the southeastern stroke belt and stroke buckle were 1.06 (95% confidence interval [CI], 0.87-1.29) and 1.19 (95% CI, 0.96-1.47), respectively. The age-sex-adjusted black/white IRR(black) was 1.51 (95% CI, 1.26-1.81), but for ages 45-54 years the IRR(black) was 4.02 (95% CI, 1.23-13.11) while for ages 85+ it was 0.86 (95% CI, 0.33-2.20). Generally, the IRRs(black) were less than the mortality rate ratios (MRRs) across age groups; however, only in ages 55-64 years and 65-74 years did the 95% CIs of IRRs(black) not include the MRR(black) . The MRRs for regions were within 95% CIs for IRRs.

INTERPRETATION

National patterns of black-white and regional differences in stroke incidence are similar to those for stroke mortality; however, the magnitude of differences in incidence appear smaller.

Stroke risk factors and outcomes among various Asian ethnic groups in Singapore

Data on interethnic differences in the Asian stroke population are limited. We evaluated the relationships among various cardiovascular risk factors, stroke subtypes, and outcomes in a multiethnic Singaporean population comprising consecutive ischemic stroke patients presenting to our tertiary center over a 1-year period. Strokes were classified based on criteria used in the Trial of Org 10172 in Acute Stroke Treatment (TOAST). Functional independence at hospital discharge was defined as a modified Rankin Scale (mRS) score of 0-2. The ethnic distribution of the study population (n = 481; mean age, 64.1 ± 11.9 years) was 74% Chinese, 17% Malay, and 9% Indian. The prevalence of risk factors was similar in the 3 ethnic groups except for diabetes (Chinese, 39.8%; Malay, 67.5%; Indian, 52.3%; P < .001). Hypertension and hypercholesterolemia were the most common cardiovascular risk factors. Lacunar stroke was the most frequent stroke subtype (47.9%). Large-artery atherosclerotic infarctions were more prevalent in Indians (25.0%), whereas lacunar infarctions occured more frequently in Chinese (51.8%; P < .01). No differences in in-hospital mortality and functional independence at discharge were seen among the 3 ethnic groups. Despite the differences in risk factors and in stroke subtypes classified by location or underlying etiology, short-term outcome measures were similar in the 3 different Asian ethnicities in Singapore.

Lower stroke mortality among Hispanics: an exploration of potential methodological confounders

OBJECTIVES

Stroke mortality rates are reported to be lower for Hispanics than non-Hispanic Whites. We investigate the degree to which this lower reported mortality is explained by inaccuracies introduced through omission of nativity, imprecise measurement of cause of death, and under-ascertainment of Hispanic ethnicity on death certificates. We used national vital registration data for the years 1989-1991 and 1999-2002, including foreign- and US-born Hispanics and non-Hispanic Whites. Hispanic deaths were adjusted for misclassification of ethnicity on the death certificate. Denominators for the rates were derived from census estimates.

RESULTS

Adjustment for nativity and death certificate misclassification removes the stroke mortality advantage for US-born Hispanic men, but not women. After adjustment, US-born Hispanic men and women have higher rates of mortality from subarachnoid hemorrhage than non-Hispanic Whites (RR: 1.23 and 1.23, respectively), but lower rates of mortality from Ischemic (RR: 0.76 and 0.73, respectively) and chronic effects of stroke (RR: 0.87 and 0.73, respectively).

CONCLUSIONS

When adjusted for misclassification the lower stroke mortality remains for Hispanic men and women at older ages. Part of the previously reported advantage is a combination of imprecise measurement and data quality.

Ethnic differences in ischemic stroke of working age in northern Israel

BACKGROUND

There are currently no comparative data about ethnic differences in ischemic stroke in Arab and Jewish populations.

METHODS

Data on 727 consecutive Arab and Jewish patients of working age (<or=65 years) with stroke were compared for risk profile, etiology, subtyping, and immediate functional outcome.

RESULTS

The mean age was 59.4 +/- 8.2 years for the Jewish and 53.7 +/- 8.6 years for the Arab patients (P = .03). Higher prevalence of diabetes was found in the Arab patients after adjustment by age, sex, and main vascular risk factors (P < .0001). After adjustment, a higher prevalence of normal transesophageal echocardiography results in the Arab population was found. Small vessel disease-related strokes were significantly more frequent in the Arab patients, whereas large vessel disease-related strokes and strokes resulting from multiple causes were significantly more frequent in the Jewish patients. No correlations were found between the high prevalence of diabetes (or any other examined factor) and the predominance of small vessel disease-related strokes in the Arab patients and large vessel disease-related strokes in the Jewish patients. There was no difference found in treatment or outcome between the Arab and the Jewish patients.

CONCLUSIONS

There are substantial differences in the risk profiles and subtyping of strokes between Arab and Jewish patients of working age.

Implications of increased C-reactive protein for cardiovascular risk stratification in black and white men and women in the US

BACKGROUND

We evaluated prevalence and correlates of increased high-sensitivity C-reactive protein (hsCRP) in a large population of blacks and whites, and the impact of hsCRP measurement on coronary heart disease risk reclassification.

METHODS

We studied 19 080 participants of the REGARDS (REasons for Geographic And Racial Differences in Stroke) study (age >45 years, without vascular diagnoses, and living dispersed across the US). A total of 8309 nondiabetic participants not using lipid-lowering medications were classified into 4 risk categories based on the Framingham vascular disease risk score. Participants with hsCRP <1 mg/L were reclassified to the next lower risk group, and those with hsCRP >3 mg/L to the next higher risk group. We also assessed reclassification of risk based on the Reynolds vascular risk score, incorporating hsCRP and family history.

RESULTS

Overall, 40% of participants had hsCRP >3 mg/L. Blacks, women, and obese people were at highest risk for increased hsCRP. Among nondiabetic women at 5%-20% Framingham vascular predicted risk, hsCRP data led to reclassification of 48% to a higher risk group and 19% to a lower risk group. For men, these percentages were 24% and 40%. Blacks were more often reclassified to a higher risk group than whites. Reynolds vascular risk score data led to reclassification of 85% of women and 67% of men, almost exclusively to a lower risk group than the Framingham vascular score.

CONCLUSIONS

In this national study, a majority of participants, especially blacks and women, were reclassified to a different 10-year vascular risk category on the basis of hsCRP testing after risk assessment. With the inclusion of hsCRP testing data, the Reynolds risk score classified the population differently than the new Framingham vascular score. .

Predictors of resuming therapy within four weeks after discharge from inpatient rehabilitation

PURPOSE

To identify the percentage of persons with stroke resuming therapy within 4 weeks of inpatient rehabilitation discharge, to compare the characteristics of those who did and did not resume therapy, and to determine the predictors of resuming physical (PT), occupational (OT), and speech (ST) therapy.

METHOD

Sociodemographic, stroke-related, and therapy data for persons with stroke (N = 131) were abstracted from inpatient rehabilitation charts. FIM, Stroke Impact Scale, Geriatric Depression Scale, and data on therapy received after discharge were also collected.

RESULTS

Logistic regression models demonstrated that minorities were less likely to resume PT (odds ratio [OR] = 0.30) and OT (OR = 0.25). Survivors with neglect/visual-field cut/spatial-perceptual loss were 2-3 times more likely to resume PT, OT, and ST. Survivors with higher scores on the SIS Physical domain subscale were less likely to resume PT (OR = 0.98) and OT (OR = 0.97). Men were 3.3 times more likely to have OT than women. Those with comprehensive health insurance were 11.2 times more likely to receive ST.

CONCLUSIONS

The benefits of outpatient therapy are not universally available to all persons with stroke. Further research needs to explore the factors that hinder the prompt resumption of therapy for minority and female persons with stroke and to test appropriate interventions.

Epidemiology of stroke in chronic heart failure patients with normal sinus rhythm: findings from the DIG stroke sub-study

BACKGROUND

Little is known about the epidemiology of stroke in chronic systolic and diastolic heart failure (HF) patients in normal sinus rhythm (NSR) receiving angiotensin-converting enzyme (ACE) inhibitors. Because all HF patients in the Digitalis Investigation Group (DIG) trial (N=7788) were in NSR and nearly all were receiving ACE inhibitors, a survey-based stroke-sub-study was conducted but its findings have never been published.

METHODS

DIG investigators confirmed a total 222 cases of stroke of which 144 had neurological deficit ≥24 h. We used logistic regression models to determine predictors of incident stroke among all 7788 patients and predictors of neurological deficit ≥24 h and all-cause mortality among 222 stroke patients.

RESULTS

Age ≥65 years (adjusted odds ratio {AOR}, 1.36; 95% confidence interval {CI}, 1.02-1.80; P=0.035), nonwhite race (AOR, 0.65; 95% CI, 0.42-0.99; P=0.047), hypertension (AOR, 1.46; 95% CI, 1.11-1.94; P=0.008), diabetes mellitus (AOR, 1.37; 95% CI, 1.03-1.82; P=0.030), and cardiomegaly (AOR, 1.39; 95% CI, 1.03-1.86; P=0.030) were independent predictors of stroke. However, among those with stroke, nonwhites had higher odds of neurological deficits ≥24 h (AOR, 2.86; 95% CI, 1.01-8.07; P=0.047) and death (AOR, 3.28; 95% CI, 1.30-8.30; P=0.012).

CONCLUSION

Older age, hypertension, diabetes and cardiomegaly were associated with increased incidence of stroke among HF patients with NSR receiving ACE inhibitors. The association of race and stroke, however, was complex. While nonwhite race was associated with decreased risk of stroke, among those with stroke, nonwhite race was associated with increased stroke severity and mortality.

Tooth loss, systemic inflammation, and prevalent stroke among participants in the reasons for geographic and racial difference in stroke (REGARDS) study

BACKGROUND AND PURPOSE

Periodontal disease results in tooth loss, may contribute to systemic inflammation, and is associated with stroke. We examined cross-sectional associations between tooth loss, inflammation markers, stroke, race, and geographic region among participants in the reasons for geographic and racial differences in stroke (REGARDS) study of whites and blacks > or =45 years.

METHODS

We studied 24,393 participants. Associations of tooth loss and inflammation markers (C-reactive protein (CRP), white blood cell count (WBC) and albumin) were examined by linear regression, and associations of tooth loss with geographic region, race, and prevalent stroke by logistic regression.

RESULTS

Compared to whites, blacks had an odds ratio of 1.48 (95% confidence interval 1.37-1.60) of having more teeth lost. There were no geographic differences in tooth loss. Compared to no tooth loss, those with 17-32 teeth lost had 1.17mg/L higher CRP (p<0.0001) and 0.18x10(9)/L higher WBC (p=0.008), did not differ in albumin, and had an odds ratio of prevalent stroke of 1.28 (1.09-1.49). Those with 1-16 teeth lost did not differ in CRP and WBC, had 0.03g/dL higher albumin (p=0.004), and had no increased stroke prevalence. CRP or WBC did not attenuate associations between tooth loss and stroke.

CONCLUSIONS

Tooth loss, which varied with race, but not region of residence, was associated with inflammation markers and stroke. The latter association was not confounded by inflammation markers.

Estimated 10-year stroke risk by region and race in the United States: geographic and racial differences in stroke risk

OBJECTIVE

Black individuals younger than 75 years have more than twice the risk for stroke death than whites in the United States. Regardless of race, stroke death is approximately 50% greater in the "stroke belt" and "stroke buckle" states of the Southeastern United States. We assessed geographic and racial differences in estimated 10-year stroke risk.

METHODS

The Reasons for Geographic and Racial Differences in Stroke study is a population-based cohort of men and women 45 years or older, recruited February 2003 to September 2007 at this report, with oversampling of stroke belt/buckle residents and blacks. Racial and regional differences in the Framingham Stroke Risk Score were studied in 23,940 participants without previous stroke or transient ischemic attack.

RESULTS

The mean age-, race-, and sex-adjusted 10-year predicted stroke probability differed slightly across regions: 10.7% in the belt, 10.4% in the buckle, and 10.1% elsewhere (p <0.001). Geographic differences were largest for the score components of diabetes and use of antihypertensive therapy. Blacks had a greater age- and sex-adjusted mean 10-year predicted stroke probability than whites: 12.0 versus 9.2%, respectively (p <0.001). Race differences were largest for the score components of hypertension, systolic blood pressure, diabetes, smoking, and left ventricular hypertrophy.

INTERPRETATION

Although blacks had a greater predicted stroke probability than whites, regional differences were small. Results suggest that interventions to reduce racial disparities in stroke risk factors hold promise to reduce the racial disparity in stroke mortality. The same may not be true regarding geographic disparities in stroke mortality.

Is there a sex or race difference in stroke mortality?

OBJECTIVES

We sought to confirm previous studies for the presence and direction of sex and race difference in stroke mortality.

METHODS

Administrative data for 40,450 Medicare beneficiaries who were hospitalized in 1994 to 1996 with acute stroke were used in regression analyses to study sex and race differences in 1-year all-cause mortality among patients with different types of stroke and cause-specific mortality in patients with all types of stroke combined. Hazard ratios were adjusted for age, sex or race, state, year of index stroke, past stroke, subsequent stroke, and fatal coexisting conditions excluding cerebrovascular diseases.

RESULTS

Men with ischemic cerebral infarction, nonspecific stroke, or all types of stroke combined were at 21% to 35% higher risk of all-cause mortality than women, but there was no sex difference among patients with subarachnoid or intracerebral hemorrhage. Nonwhite patients with ischemic cerebral infarction had 11% higher all-cause mortality than white patients, but there were no race differences after adjustments for fatal coexisting conditions. Compared with women, mortality was higher in men with all types of stroke regardless of the cause of death. There was higher risk of death caused by cerebrovascular diseases in white patients with all types of stroke combined, but the risk of death caused by cardiovascular diseases other than ischemic heart disease was higher in nonwhite patients.

CONCLUSIONS

There was no sex or race difference in all-cause mortality in patients with hemorrhagic stroke and higher risk in men with ischemic and nonspecific stroke. Relatively higher risk of mortality caused by cerebrovascular diseases was found in men and white patients.

Regional differences in African Americans' high risk for stroke: the remarkable burden of stroke for Southern African Americans

PURPOSE

The stroke mortality rate for African Americans aged 45 to 64 years is 3 to 4 times higher than for whites of the same age, with a decreasing black-to-white mortality ratio with increasing age. There is also a "STROKE BELT" with higher stroke mortality in the southeastern United States. This study assesses if there are also geographic variations in the magnitude of the excess stroke mortality for African Americans.

METHODS

The age- and sex-specific black-to-white mortality ratio was calculated for each of 26 states with a sufficient African American population for stable estimates. The southern excess was calculated as the percentage excess of southern over nonsouthern rates.

RESULTS

Across age and sex strata, the black-to-white stroke mortality ratio was consistently higher for southern states, with an average black-to-white stroke mortality ratio that ranged from 6% to 21% higher among southern states than in nonsouthern states.

CONCLUSIONS

The increase in stroke mortality rates for African Americans in southern states is even larger than expected. That southern states that are not part of the "STROKE BELT" (Virginia and Florida) also have an elevated black-to-white mortality ratio suggests the mechanism of higher risk for African Americans may be independent of the causes contributing to "STROKE BELT."

Carotid stenosis in a multiethnic population

BACKGROUND

Carotid stenosis is an important, treatable cause of stroke. Several population-based studies have shown ethnic differences in the prevalence of carotid atherosclerosis. This study was performed at a large multiethnic hospital to clarify these differences.

METHODS

One thousand six carotid artery ultrasounds performed by the Department of Radiology at Los Angeles County General Hospital over a 4-year period were reviewed. Patients were classified as Caucasian (n=151), Hispanic (n=515), Black (n=173), or Asian (n=167) by self-declaration and birthplace. Carotid stenosis was defined as mild (1% to 39%), moderate (40% to 59%), severe (60% to 79%), critical (80% to 99%), or total (100%).

RESULTS

Twenty and one-half percent of Caucasian patients had greater than 59% stenosis compared with 10.1% of Hispanics, 8.7% of Blacks, and 10.7% of Asians (P<0.001). Nine and two-tenths percent of Caucasians had greater than 79% stenosis compared with 4.3% of Hispanics, 2.9% of Blacks, and 2.8% of Asians (P<0.001). There were no significant differences in age or gender representations between ethnic groups, and the indications for ordering carotid duplex sonography also did not vary by race. Caucasians and Blacks had a higher prevalence of cardiac disease, smoking, and heavy alcohol abuse. Hispanics had higher rates of diabetes.

CONCLUSIONS

These results indicate that significant differences in the degree of carotid stenosis exist among ethnic groups. Caucasian patients in our series showed a statistically higher likelihood of having a severe or critical level of stenosis. These findings may have implications for the allocation of health care resources as ethnic minorities compose a greater proportion of the population.

Echocardiographic left ventricular mass index predicts incident stroke in African Americans: Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND AND PURPOSE

Despite theories that link stroke to left ventricular mass, few large, population-based studies have examined the predictive value of echocardiographically derived left ventricular mass index (LVMI) to incident stroke in African Americans.

METHODS

Participants in the Jackson cohort of the Atherosclerotic Risk in Communities study have had extensive baseline evaluations, have undergone echocardiography during the third examination (1993-1995), and have been followed up for incident cardiovascular disease including ischemic stroke.

RESULTS

The study population consisted of 1792 participants, of whom 639 (35.7%) were men and the mean+/-SD age was 58.8+/-5.7 years. Compared with those without ischemic stroke, those with ischemic stroke had a higher frequency of hypertension (85.6% vs 58.7%) and diabetes (46.9% vs 21.0%). Left ventricular hypertrophy was more prevalent in those with stroke (62.2% vs 38.6%). During a median follow-up of 8.8 years, 98 incident strokes occurred (6.5 per 1000 person-years). LVMI was independently associated with stroke after adjusting for age, sex, hypertension, systolic blood pressure, smoking, diabetes, total to HDL cholesterol ratio, body mass index, and low left ventricular ejection fraction (adjusted hazard ratio per 10 g/m(2.7) increment of LVMI=1.15; 95% CI, 1.02 to 1.28). The relation remained statistically significant after adding left atrial size and mitral annular calcification to the multivariable model.

CONCLUSIONS

In this large, population-based African American cohort, we found that echocardiographic LVMI was an independent predictor of incident ischemic stroke even after taking into account traditional clinical risk factors.

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.

Prevalence of restless legs syndrome among native South Americans residing in coastal and mountainous areas

OBJECTIVE

To determine the prevalence of restless legs syndrome (RLS) in native South Americans and identify the impact of geographic location.

PARTICIPANTS AND METHODS

An epidemiological telephone survey of RLS symptoms involving natives from coastal and mountainous areas was performed during July 2, 2004, through September 28, 2004. The process consisted of 2 phases: the creation of the epidemiological instrument and the telephone survey.

RESULTS

Five hundred adults, 250 from the mountainous regions and 250 from the coastal region (190 men and 310 women; age range, 25-85 years) were interviewed and subsequently divided on the basis of International Restless Legs Syndrome Study Group criteria into those who had RLS (RLS+ group) and those who did not (RLS- group). Ten (2.0%) had RLS. The overall rate of RLS in adults living in the mountainous region at 2816 m above sea level (3.2% [8/250]) was significantly higher than that for adults living in the coastal region at 4 m above sea level (0.80% [2/250]; P = .002). The mean age of the RLS+ group was 49.5 years (SD, 15.20 years; range, 25-85 years).

CONCLUSION

Native South American adults have a prevalence of RLS well below that reported in populations with European ancestry but similar to that in Asian and Turkish populations. Furthermore, in Ecuador, geographic differences were identified in areas of similar population density.

A possible explanation for the racial difference in distribution of large-arterial cerebrovascular disease: ancestral European settlers evolved genetic resistance to atherosclerosis, but confined to the intracranial arteries

The pattern of cerebral atherosclerosis is not the same among different races. White patients rarely have intracranial large arterial steno-occlusive disease even if their systemic arteries are extensively involved, while non-white patients frequently have their intracranial arteries affected. We postulate that during human population diversification, those who settled in Europe had acquired a stroke-suppressor genotype that increases their resistance against atherogenesis, but with protection confined to the intracranial large arteries. The contemporary affluent lifestyle accelerates the development of atherosclerosis. In the whites, it involves the whole arterial bed except the intracranial vessels. People living in non-Western countries used to have a healthier way of living. They did not develop significant atherosclerotic diseases until recently when a westernised lifestyle was adopted. Unlike the whites, their intracranial arteries will not be spared. Atherosclerosis has become a major cause of premature mortality in the modern world, and an anti-atherogenic mechanism would confer a selection advantage. With further adaptive intensification, this protection may extend to the rest of the arterial bed. As a result, future Homo sapiens will be able to tolerate an affluent lifestyle without much adverse sequel such as premature vascular death. Alternatively, if the mediator of this anti-atherogenic mechanism can be identified and applied therapeutically, we will have an ultimate mean to prevent atherosclerosis.

Survival differences after stroke in a multiethnic population: follow-up study with the South London stroke register

OBJECTIVES

To identify ethnic differences in survival after stroke and examine the factors that influence survival.

DESIGN

Population based stroke register with follow-up.

SETTINGS

South London stroke register.

PARTICIPANTS

2321 patients with first stroke registered between January 1995 and December 2002.

MAIN OUTCOME MEASURES

Sociodemographic factors, risk factors for stroke and their management, severity of stroke, and acute service provision factors. Survival analysis with Kaplan-Meier curves, log rank test, and Cox's proportional hazard model with stratification.

RESULTS

In univariable analyses of survival, outcome was better for black people than white people (median 33.7 v 20.0 months). After stratification by socioeconomic status, type of stroke, and Glasgow coma score, and adjustment for other potential confounders, being black was generally associated with better survival, taking into account the interaction between ethnicity and age, and ethnicity and prior Barthel score. Of the risk factors for stroke considered, current smoking (hazard ratio 1.21, 95% confidence interval 1.01 to 1.45, P = 0.044), untreated atrial fibrillation (1.36, 1.08 to 1.72, P = 0.009), untreated diabetes (1.53, 1.05 to 2.22, P = 0.027), and treated diabetes (1.61, 1.27 to 2.03, P < 0.001) were associated with reduced survival.

CONCLUSION

In general, black patients in a south London population with first ever stroke are more likely to survive than white patients, the exceptions being in those aged < 65 and those with a prior Barthel score < 15. Some pre-stroke risk factors that have the potential to be modified, including the appropriate treatment of existing health problems, have a strong impact on survival.

Stroke burden in Mexican Americans: the impact of mortality following stroke

PURPOSE

To estimate ethnic-specific all-cause mortality risk following ischemic stroke and to compare mortality risk by ethnicity.

METHODS

DATA from the Brain Attack Surveillance in Corpus Christi Project, a population-based stroke surveillance study, were used. Stroke cases between January 1, 2000 and December 31, 2002 were identified from emergency department (ED) and hospital sources (n = 1,234). Deaths for the same period were identified from the surveillance of stroke cases, the Texas Department of Health, the coroner, and the Social Security Death Index. Ethnic-specific all-cause cumulative mortality risk was estimated at 28 days and 36 months using Kaplan Meier analysis. Cox proportional hazards regression was used to compare mortality risk by ethnicity.

RESULTS

Cumulative 28-day all-cause mortality risk for Mexican Americans (MAs) was 7.8% and for non-Hispanic whites (NHWs) was 13.5%. Cumulative 36-month all-cause mortality risk was 31.3% in MAs and 47.2% in NHWs. MAs had lower 28-day (RR = 0.58; 95% CI: 0.41, 0.84) and 36-month all-cause mortality risk (RR = 0.79, 95% CI: 0.64, 0.98) compared with NHWs, adjusted for confounders.

CONCLUSIONS

Better survival after stroke in MAs is surprising considering their similar stroke subtype and severity compared with NHWs. Social or psychological factors, which may explain this difference, should be explored.

Epidemiology of stroke in African Americans and Hispanic Americans

Many minorities continue to experience disparities in the level of their personal health and overall health care in the United States. This article explores disparities in stroke as they relate to two minority populations: African Americans and Hispanic Americans. These two groups have been chosen for review and discussion because the available epidemiologic databases are relatively broad, and the authors have personal experience in the conduct of research studies in these populations.

Outcomes of a program to enhance exercise self-efficacy and improve fitness in Black and Hispanic college-age women

A quasi-experimental design was used to test the outcomes of an exercise program directed towards Black and Hispanic college-age women. Forty-four women (36 Black, 7 Hispanic, and 1 Black/Hispanic) attended exercise classes three times per week for 16 weeks. At program completion, women were classified as either high attendees (n = 26) or low attendees (n = 18). Compared to low attendees, the high attendees had significantly higher exercise self-efficacy (p <.001), perceived benefits and barriers (p =.004), aerobic fitness, flexibility, muscle strength, and percentage of body fat (all p <.001). Daily activity levels improved significantly in the high attendance group following the program (p <.001) and at 8 weeks post-program completion (p =.01).

Family history of stroke among Mexican-American and non-Hispanic white patients with stroke and TIA: implications for the feasibility and design of stroke genetics research

Family history of stroke may differ by ethnicity. This study examined the associations of ethnicity and stroke risk factors with family history of stroke using data from the Brain Attack Surveillance in Corpus Christi Project. A random sample of stroke/transient ischemic attack cases was interviewed about family history of stroke (n = 524). Thirty-six percent of the cases reported a family history of stroke, with 26% reporting a parental and 13% a sibling history. Compared to non-Hispanic whites (NHWs), Mexican-Americans (MAs) were two times (OR = 2.07; 95% CI: 1.09-3.95) more likely to have a sibling with stroke. More MAs (8.1%; 95% CI: 4.6-11.6) had living siblings with stroke compared to NHWs (1.9%; 95% CI: 0.1-3.8). Since MAs are more likely to have living siblings with stroke compared with NHWs, MAs may be a more feasible population for family stroke studies than predominantly white populations.

Diabetes mellitus as a risk factor for stroke incidence and mortality in Mexican American older adults

BACKGROUND

Little is known regarding diabetes mellitus as a risk factor for stroke incidence and death in older Mexican Americans. The authors studied diabetes and other potential risk factors for stroke in a sample of community-dwelling older Mexican Americans.

METHODS

A prospective cohort design was used that involved the Hispanic Established Population for the Epidemiologic Study of the Elderly, a longitudinal study using a weighted probability sample of Mexican Americans (aged older than 65 years) living in the southwestern United States. 3050 older Mexican American persons were originally interviewed and tested at baseline and then followed with reassessment at 2, 5, and 7 years. The incidence of stroke and stroke death were studied for the participants during a 7-year follow-up period.

RESULTS

690 participants were identified at baseline with diabetes. 238 participants experienced a first-time stroke during the follow-up period. 66 died as a result of a stroke. Cox proportional hazard regression analysis revealed an increased hazard ratio (HR) for stroke in persons with diabetes (HR, 1.80; 95% confidence interval [CI], 1.32 to 2.44; p <.0002) when adjusted for age, sex, body mass index, smoking, systolic blood pressure, previous heart attack, and lower extremity function. The stroke mortality rate was also higher (HR, 2.02; 95% CI, 1.04 to 3.93) for persons with diabetes when adjusted for covariates.

CONCLUSION

Diabetes was associated with an increased incidence of stroke and death in older Mexican Americans, particularly those taking insulin.

Relation of age and race with hospital death after acute myocardial infarction

BACKGROUND

Prior studies have suggested that young blacks with acute myocardial infarction (AMI) may have higher hospital mortality rates than whites of similar age. However, the influence of age and race on short-term death has not been explored in detail. We examined the relation of age and race on short-term death in a large AMI population and ascertained the factors that may have contributed to differences in mortality rates.

METHODS

We compared the crude and adjusted hospital mortality rates stratified by age among 40,903 blacks and 501,995 whites with AMI enrolled in the National Registry of Myocardial Infarction-2 in 1482 participating US hospitals from June 1994 through March 1998.

RESULTS

Overall crude mortality was lower among blacks compared with whites (10.9% vs 12.0%, P <.0001). However, blacks had a significantly higher crude mortality rate compared with the whites in the age groups <65 years (<45 years, and 5-year age groups between 45 and 64 years). There was a statistically significant interaction between age and black race on hospital death (P value for interaction <.001). Each 5-year decrement in age from 85 years was associated with 7.2% higher odds of death in blacks compared with whites (95% CI, 5.7% to 7.6%). After adjusting for differences in the baseline, clinical presentation, early treatment, and hospital characteristics, 5-year decrements in age was still associated with increases in the odds for death in blacks compared with whites (5.4%; 95% CI, 3.6% to 7.2%). This interaction between age and black race was present in both sexes but was stronger among men.

CONCLUSIONS

Blacks younger than 65 years had higher hospital mortality rates compared with whites hospitalized for AMI, and decreasing age was associated with progressively higher risk of hospital death for blacks. Differences in the clinical presentation, early treatment, and hospital characteristics could only partly explain this age-race interaction.