A comparative analysis of risk factors for stroke in blacks and whites: the Atherosclerosis Risk in Communities study

Incidence of Stroke in People With Diabetes Compared to Those Without Diabetes: A Systematic Review

BACKGROUND

One of the goals of the St. Vincent Declaration was to reduce serious complications of diabetes, including strokes. However, it remains uncertain whether this goal has been achieved.

STUDY AIM

To evaluate the incidence of stroke in the diabetic population and its differences regarding sex, ethnicity, age, and region, to compare the incidence rate in people with and without diabetes, and to investigate time trends.

MATERIALS AND METHODS

A systematic review was conducted according to the guidelines for meta-analysis of observational studies in epidemiology (the MOOSE group) and the PRISMA group guidelines.

RESULTS

Nineteen of the 6.470 studies retrieved were included in the analysis. The incidence of stroke in the population with diabetes ranged from 238 per 100,000 person-years in Germany in 2014 to 1191 during the 1990s in the United Kingdom. The relative risk comparing people with diabetes to those without diabetes varied between 1.0 and 2.84 for total stroke, 1.0 and 3.7 for ischemic stroke, and 0.68 and 1.6 for hemorrhagic stroke. Differences between fatal and non-fatal stroke were significant, depending on the time period and the population. We found decreasing time trends in people with diabetes and stable incidence rates of stroke over time in people without diabetes.

CONCLUSION

The considerable differences between results can partly be explained by differences in study designs, statistical methods, definitions of stroke, and methods used to identify patients with diabetes. The lack of evidence arising from these differences ought to be rectified by new studies.

Racial differences in persistence to secondary prevention medication regimens after ischemic stroke

BACKGROUND

Prior stroke is one of the biggest risk factors for future stroke events. Effective secondary prevention medication regimens can dramatically reduce recurrent stroke risk. Guidelines recommend the use of antithrombotic, antihypertensive and lipid-lowering medications after stroke. Medication adherence is known to be better in the presence of a caregiver but long-term adherence after stroke is unknown and disparities may persist.

METHODS

We examined the effects of race and sex on baseline prescription and maintenance of secondary prevention regimens in the presence of a caregiver using the Caring for Adults Recovering from the Effects of Stroke (CARES) study, an ancillary study of the national REasons for Geographic and Racial Differences in Stroke (REGARDS).

RESULTS

Incident ischemic stroke survivors (N = 172; 36% Black) with family caregivers had medications recorded at hospital discharge and on average 9.8 months later during a home visit. At discharge, antithrombotic prescription (95.9%), lipid-lowering medications (78.8%) and antihypertensives (89.9%) were common and there were no race or sex differences in discharge prescription rates. One year later, medication persistence had fallen to 86.6% for antithrombotics (p = 0.002) and 69.8% for lipid lowering (p = 0.008) but increased to 93.0% for antihypertensives (p = 0.30). Blacks were more likely to have discontinued antithrombotics than Whites (18.3% v 7.7%, p = 0.04). No significant differences in persistence were seen with age, sex, income, depression, or cognitive impairment.

CONCLUSIONS

Medication persistence was high in this sample, likely due to the presence of a caregiver. In our cohort, despite similar prescription rates at the time of hospital discharge, Black stroke survivors were more than twice as likely to stop antithrombotics than Whites. The effect of changes in patterns of medication usage on health outcomes in Black stroke survivors warrants continued investigation.

A cohort study on the relationship between education level and high-risk population of stroke

Objective

To explore the relationship between education level and high-risk population among stroke screening populations in Zunyi City, China.

Methods

The cluster sampling method was adopted to collect the medical history, laboratory examinations and physical examinations for the permanent residents of Zunyi City, Guizhou Province. Taking education level as a key socioeconomic status (SES) indicator, multivariate logistic regression analysis was used to evaluate the risk factors of high-risk groups with different education levels.

Results

Among the included 4149 subjects, 494 were in the high-risk group and 3655 were in the non-high-risk group. The proportion of the high-risk population with education level ≥ high secondary school (8.7%) was significantly higher than that of the low-risk population. After adjusting for age, gender, and BMI, the OR of those with education leve l ≥ high secondary school was 2.8 (95% CI 1.9-4.2), which was significantly higher than those with education level of illiterate/primary school. In the model adjusted for all confounding factors, compared with illiterate/primary school, people with education level ≥ high secondary school were more likely to be at high risk of stroke (OR 3.0, 95% CI 1.9-4.6).

Conclusion

Education level ≥ high secondary school is an independent influencing factor for the high-risk population of stroke in Zunyi, which may be related to smoking and lipid metabolism abnormalities of people with high education level. Key interventions for high-risk populations with high education levels may have positive significance in reducing the incidence of stroke.

The association of von willebrand factor and its cleaving protease (ADAMTS13) with health behaviours in young black and white adults: the African-PREDICT study

To reduce cardiovascular risks imposed by Von Willebrand factor (vWF) and ADAMTS13 from young ages, knowledge on health behaviours that may affect their concentrations is essential. We therefore determined whether circulating vWF antigen and ADAMTS13 associate with health behaviours. We included 1196 black and white healthy adults aged 20-30 years and used questionnaires for socio-economic, tobacco and alcohol use data. vWF:Ag was measured from citrated samples and ADAMTS13, cotinine and gamma-glutamyl transferase (GGT) from serum. Salt intake was estimated from 24-hour urine and body mass index (BMI) was calculated. Black adults had higher vWF:Ag and lower ADAMTS13 levels compared to whites (all p < 0.001). In multiple regression analyses in the total group, vWF:Ag associated positively with BMI (p = 0.037), while ADAMTS13 associated negatively with BMI (p = 0.016) and cotinine (p = 0.029); and positively with GGT (p = 0.002). When exploring within each ethnic group, vWF:Ag associated positively with estimated salt intake (p = 0.043) only in blacks. In whites, vWF:Ag associated positively with BMI (p = 0.023) while ADAMTS13 associated positively with GGT (p = 0.003) and negatively with cotinine (p = 0.041). Young black adults may have an increased thrombotic risk due to higher vWF and lower ADAMTS13. The ethnic-specific associations observed may have implications for public health initiatives to improve cardiovascular outcomes.

Characteristics and Cardiovascular Disease Event Rates among African Americans and Whites Who Meet the Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk (FOURIER) Trial Inclusion Criteria

PURPOSE

Determine the risk for cardiovascular disease (CVD) events among adults with clinically evident CVD who meet the inclusion criteria for the FOURIER clinical trial on PCSK9 inhibition in a real-world database.

METHODS

We analyzed data from 2072 African American and 2972 white REasons for Geographic And Racial Differences in Stroke (REGARDS) study participants 45-85 years of age with clinically evident CVD. Study participants meeting the FOURIER inclusion criteria (one major or two minor cardiovascular risk factors, fasting LDL cholesterol ≥ 70 mg/dL or non-HDL cholesterol ≥ 100 mg/dL, triglycerides ≤ 400 mg/dL, and taking statin) were followed for CVD events (myocardial infarction, stroke, coronary revascularization, and CVD death) from baseline in 2003-2007 through 2014.

RESULTS

Overall, 771 (37.2%) African Americans and 1200 (40.4%) whites met the FOURIER inclusion criteria. The CVD event rate per 1000 person years was 60.6 (95% CI 53.6-67.6) among African Americans and 63.5 (95% CI 57.7-69.3) among whites. The risk for CVD events among adults meeting the FOURIER inclusion criteria was higher for those with a history of multiple cardiovascular events (hazard ratios among African Americans and whites 1.34 [95% CI 1.05-1.71] and 1.34 [1.10-1.63], respectively), a prior coronary revascularization (1.44 [1.13-1.84] and 1.23 [1.00-1.52], respectively), diabetes (1.38 [1.08-1.76] and 1.41 [1.15-1.72], respectively), reduced glomerular filtration rate (1.63 [1.26-2.11] and 1.29 [1.03-1.62], respectively), and albuminuria (1.77 [1.37-2.27] and 1.33 [1.07-1.65], respectively).

CONCLUSIONS

The CVD event rate is high among African Americans and whites meeting the FOURIER inclusion criteria. Characteristics associated with a higher CVD risk may inform the decision to initiate PCSK9 inhibition.

Does the Association of Diabetes With Stroke Risk Differ by Age, Race, and Sex? Results From the REasons for Geographic and Racial Differences in Stroke (REGARDS) Study

OBJECTIVE

Given temporal changes in diabetes prevalence and stroke incidence, this study investigated age, race, and sex differences in the diabetes-stroke association in a contemporary prospective cohort, the REasons for Geographic and Racial Differences in Stroke (REGARDS) Study.

RESEARCH DESIGN AND METHODS

We included 23,002 non-Hispanic black and white U.S. adults aged ≥45 years without prevalent stroke at baseline (2003-2007). Diabetes was defined as fasting glucose ≥126 mg/dL, random glucose ≥200 mg/dL, or use of glucose-lowering medication. Incident stroke events were expert adjudicated and available through September 2017.

RESULTS

The prevalence of diabetes was 19.1% at baseline. During follow-up, 1,018 stroke events occurred. Among adults aged <65 years, comparing those with diabetes to those without diabetes, the risk of stroke was increased for white women (hazard ratio [HR] 3.72 [95% CI 2.10-6.57]), black women (HR 1.88 [95% CI 1.22-2.90]), and white men (HR 2.01 [95% CI 1.27-3.27]) but not black men (HR 1.27 [95% CI 0.77-2.10]) after multivariable adjustment. Among those aged ≥65 years, diabetes increased the risk of stroke for white women and black men, but not black women (HR 1.05 [95% CI 0.74-1.48]) or white men (HR 0.86 [95% CI 0.62-1.21]).

CONCLUSIONS

In this contemporary cohort, the diabetes-stroke association varied by age, race, and sex together, with a more pronounced effect observed among adults aged <65 years. With the recent increase in the burden of diabetes complications at younger ages in the U.S., additional efforts are needed earlier in life for stroke prevention among adults with diabetes.

Associations of Multimorbid Medical Conditions and Health-Related Quality of Life Among Older African American Men

Background

African American (AA) men battling multiple morbidities are tasked with managing the components of each condition and are at greater risk for adverse outcomes such as poor health-related quality of life (QOL), disability, and higher mortality rates.

Method

Baseline data for AA men from the University of Alabama at Birmingham Study of Aging were utilized. Factor analysis was used to categorize medical conditions and create factor scores. Covariate-adjusted regression models assessed the relationships between categories of conditions and physical and mental health-related QOL as assessed by the SF-12.

Results

The mean age of the sample of 247 AA men was 75.36 years and 49% lived in rural areas. Medical conditions fit into three factors: metabolic syndrome, kidney failure and neurological complications, and COPD and heart disease. Covariate-adjusted models revealed that low education, higher levels of income difficulty, and higher scores on metabolic syndrome and COPD and heart disease factors were associated with lower scores on physical health-related QOL, p's < .05. Higher levels of income difficulty were also associated with lower scores on mental health-related QOL.

Discussion

These findings suggest the importance of examining clusters of comorbid medical conditions and their relationships to outcomes within older African American men.

Education, Socioeconomic Status, and Intelligence in Childhood and Stroke Risk in Later Life: A Meta-analysis

BACKGROUND

Stroke is the second most common cause of death, and a common cause of dependency and dementia. Adult vascular risk factors and socioeconomic status (SES) are associated with increased risk, but less is known about early life risk factors, such as education, childhood SES, or intelligence (IQ).

METHODS

We comprehensively searched Medline, PsycINFO, and EMBASE from inception to November 2015. We included all studies reporting data on >50 strokes examining childhood/premorbid IQ, SES, and education. Two reviewers independently screened full texts and extracted and cross-checked data, including available risk factor adjustments. We meta-analyzed stroke risk using hazard ratios (HR), odds ratios (OR), and mean differences (MD). We tested effects of study and participant characteristics in sensitivity analyses and meta-regression, and assessed heterogeneity and publication bias.

RESULTS

We identified 90 studies examining stroke risk and education (79), SES (10), or IQ (nine) including approximately 164,683 stroke and over 5 million stroke-free participants. Stroke risk increased with lower education (OR = 1.35, 95% CI = 1.24, 1.48), SES (OR = 1.28, 95% CI = 1.12, 1.46), and IQ (HR = 1.17, 95% CI = 1.00, 1.37) in studies reporting point estimates, with similar associations for MD. We found minimal publication bias. Between-study heterogeneity was partly explained by participant age and case ascertainment method.

CONCLUSIONS

Education, childhood SES, and intelligence have modest but important associations with lifetime stroke, and hence dementia, risks. Future studies distinguishing between the individual and combined effects of education, childhood SES and intelligence are needed to determine the independent contribution of each factor to stroke risk. See video abstract at, http://links.lww.com/EDE/B210.

Associations of Brain Structure With Adiposity and Changes in Adiposity in a Middle-Aged and Older Biracial Population

Background

Studies of adiposity and brain pathology in African Americans (AA) are sparse despite higher rates of obesity, dementia, and dementia-associated brain pathology in AA. This study examined relations of adiposity to white matter hyperintensities (WMH) and total brain volume (TBV) in AA and non-Hispanic whites (NHW).

Methods

Waist circumference (WC) and body mass index (BMI) were measured in the Genetic Epidemiology Network of Arteriopathy study at Visits 1 (mean age 57 [±11]) and 2 (mean age 61 [±10], mean 5.2 years later). Brain MRIs were obtained shortly after Visit 2 in 1,702 participants (64% women, 48% AA). Multilevel linear regression using generalized estimating equation estimated associations of adiposity (cross-sectional) or adiposity changes with WMH (accounting for intracranial size) or TBV adjusting for demographics, cardiovascular risk factors, and incorporating adiposity-by-race interactions. Adiposity-by-age interactions were examined.

Results

Concurrent TBV was inversely associated with BMI (β = -2.76 [95% confidence interval (CI): -4.99, -0.53]) and WC (β = -2.19 [CI: -4.04, -0.34]). Concurrent WMH were negatively associated with BMI (β = -0.04 [CI: -0.06, -0.01]) and, among NHW, with WC (β = -0.04 [CI: -0.06, -0.02]) but not with changes in BMI or WC. BMI increases were associated with lower TBV (β = -16.20, [CI: -30.34, -2.06]) in AA but not in NHW (β = -2.76 [CI: -14.02, 8.51]), although race-by-adiposity interactions were not supported. WC increases were not associated with MRI outcomes.

Conclusion

Greater measures of obesity and increases in measures of obesity, which are common in mid-life, could be detrimental to brain health, particularly in AA.

Brain Aging in African-Americans: The Atherosclerosis Risk in Communities (ARIC) Experience

Reported rates of dementia differ by race, although most studies have not focused on carefully measured outcomes, confounding by education or other demographic factors, nor have they studied other outcomes other than dementia. In this review we will discuss the experience in the Atherosclerosis Risk in Communities (ARIC) study evaluating racial disparities relating to stroke, subclinical brain infarction, leukoaraiosis, as well as cognitive change and dementia. ARIC is a biracial cohort of 15,792 participants from four U.S. communities, initially recruited in 1987-1989, and seen at a total of 5 in-person visits (most recently seen in 2011-2013) with annual follow-up phone calls. We will provide evidence from ARIC studies that disproportionate rates of vascular risk factors explain at least some of these observed disparities by race, but particular risk factors, including diabetes, may differentially affect the brain in African-American versus white participants. In addition, we will review some of the disparities by race in studies focusing on the genetics of stroke, small vessel disease, and dementia.