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

Hypertension Severity as Quantified by Hypertension Daily Dose and Blood Pressure With Risk of Stroke in REGARDS

BACKGROUND

It is unknown how blood pressure (BP) relates to stroke risk across levels of hypertension daily dose (HDD)-quantified antihypertensive medication intensity.

METHODS AND RESULTS

The REGARDS (Reasons for Geographic and Racial Differences in Stroke) study enrolled 30 239 participants from the 48 contiguous US states in 2003 to 2007 with in-person follow-up in 2013 to 2016 (Visit 2). We included those without prior stroke at Visit 2, treating this visit as T0. Biannual phone calls and medical record review ascertained incident stroke events. Cox proportional hazard models estimated the hazard ratio (HR) of incident stroke by treatment intensity defined by systolic BP stages and HDD groupings. There were 344 stroke events over a median 5.5 years. Relative to systolic BP <120 mm Hg and no antihypertensive medications, the stroke HR was 2.86 (95% CI, 1.68-4.85) for systolic BP 140 to 159 mm Hg and HDD tertile 2, 2.33 (1.37-3.97) for systolic BP 140 to 159 mm Hg and HDD tertile 3, 3.08 (1.20-7.88) for systolic BP ≥160 mm Hg and HDD tertile 2, and 3.66 (1.61-8.30) for systolic BP ≥160 mm Hg and HDD tertile 3. Stroke risk was similar across HDD levels for people with systolic BP <140 mm Hg.

CONCLUSIONS

Among adults without prior stroke, systolic BP ≥140 mm Hg and HDD tertile ≥2 was associated with greater stroke risk. For adults with BP <140 mm Hg, stroke risk was similar despite cumulative dose of antihypertensive medications used. These findings support the practice of BP-lowering medications to mitigate stroke risk.

The incidence of stroke and contribution of risk factors for stroke in high-risk stroke population in southwestern China

OBJECTIVE

To estimate the incidence of stroke and determine the role that risk factors play in the high-risk stroke populace in southwest China.

METHODS

This research employed a prospective cohort design that focused on the community. Eight communities in southwest China were selected randomly for this study. The residents aged 40 years and older who volunteered to participate were surveyed through face-to-face interviews. Those with a history of stroke or at least three of the eight stroke-related risk factors were categorized as the high-risk stroke population. A total of 2698 high-risk individuals were included in the study after a 4.7-year follow-up period. The incidence of stroke and the association between risk variables and stroke occurrence were estimated.

RESULTS

During 4.7-year follow-up, the incidence of total stroke, ischemic stroke, and hemorrhagic stroke in high-risk stroke population were 5.0 %, 4.4 % and 0.9 % respectively. It should be noted that some participants experienced both cerebral infarction and cerebral hemorrhage during the follow-up period. The multivariate analytic model revealed that a personal history of stroke (OR=3.397, 95 % CI 2.365-4.878, p<.001) was substantially linked with an elevated risk of overall stroke. This correlation remained consistent for both ischemic and hemorrhagic stroke.

CONCLUSIONS

This study revealed a high prevalence and incidence of stroke among a high-risk group in southwestern China. Furthermore, it demonstrated that individuals with a personal history of stroke are at an elevated risk of future stroke, suggesting the need for additional precautions in this population.

The interaction between estimated glomerular filtration rate and dietary magnesium intake and its effect on stroke prevalence: a cross-sectional study spanning 2003-2018

Background

Despite the known associations of dietary magnesium intake and estimated glomerular filtration rate (eGFR) with cardiovascular diseases, their combined effects on stroke risk remain unclear. Therefore, this study aims to explore the associations of dietary magnesium intake and eGFR with stroke risk.

Methods

The National Health and Nutrition Examination Survey (NHANES) data of 37,637 adult participants (≥18 years) from 2003 to 2018 was analyzed. Dietary magnesium intake was categorized as low (≤ 254 mg/day) and normal (> 254 mg/day) based on experimental data. Multiple logistic regression analyses and interaction tests were conducted to assess the associations of dietary magnesium intake and eGFR with stroke risk, with a focus on the interaction between different chronic kidney disease (CKD) stages based on eGFR levels and dietary magnesium intake. Additional analyses included multiplicative interaction analysis, restricted cubic spline analysis, and subgroup evaluations by age, sex, and ethnicity.

Results

Dietary magnesium intake and eGFR were inversely correlated with the risk of stroke. Participants with low dietary magnesium intake had a higher stroke risk than those with normal magnesium intake (odds ratio [OR] 1.09, 95% confidence interval [CI]: 1.03-1.42). Likewise, low eGFR was associated with an elevated stroke risk compared with normal eGFR (OR 1.56, 95% CI: 1.15-2.13). Furthermore, the two factors showed a multiplicative interaction effect on stroke risk (OR 1.05, 95% CI: 1.01-1.09). We observed a significant interaction between stage G3 CKD and low dietary magnesium intake (OR 1.05, 95% CI: 1.01-1.09), suggesting a potential association with stroke risk. However, similar associations were not observed for stages G4 and G5, possibly due to the smaller number of participants with G4 and G5 CKD. The restricted cubic spline analysis revealed a non-linear relationship between dietary magnesium intake, eGFR, and stroke risk. The interaction between magnesium deficiency and low eGFR persisted in participants aged >60 years, as well as in females, non-Hispanic Black people, and people of other races.

Conclusion

Dietary magnesium intake and eGFR correlate negatively with stroke prevalence. Moreover, there was an interaction between dietary magnesium intake and stroke prevalence across different CKD stages. Further large-scale prospective studies are needed to analyze the potential relationship between dietary magnesium intake, eGFR, and stroke.

Soluble CD14 and Incident Diabetes Risk: The REasons for Geographic and Racial Differences in Stroke (REGARDS) Study

Context

Soluble CD14 (sCD14) is an inflammation biomarker with higher concentrations in White than Black adults. Higher sCD14 is seen in insulin resistance and diabetes. There are limited data on the relationship between sCD14 and incident diabetes.

Objective

To determine the association of sCD14 with incident diabetes risk in a large biracial US cohort and evaluate whether relationships differ by race.

Design

This study included 3401 Black and White participants from the REasons for Geographic And Racial Differences in Stroke (REGARDS) study without baseline diabetes who completed baseline and follow-up in-home visits. Modified Poisson regression models estimated risk ratios (RR) of incident diabetes per 1-SD increment sCD14, with adjustment for risk factors. A sCD14-by-race interaction evaluated whether associations differed by race.

Results

There were 460 cases of incident diabetes over a mean 9.5 years of follow-up. The association of sCD14 with diabetes differed by race (P for interaction < .09). Stratifying by race, adjusting for age, sex, and region, higher sCD14 was associated with incident diabetes in White (RR: 1.15; 95% CI: 1.01, 1.33) but not Black participants (RR: 0.96; 95% CI: 0.86, 1.08). In models adjusted for clinical and sociodemographic diabetes risk factors, the association was attenuated among White participants (RR: 1.10; 95% CI: 0.95, 1.28) and remained null among Black participants (RR: 0.90; 95% CI: 0.80, 1.01).

Conclusion

sCD14 was associated with incident diabetes risk in White but not Black adults, but this association was explained by diabetes risk factors.

Racial Disparities in Blood Pressure at Time of Acute Ischemic Stroke Presentation: A Population Study

BACKGROUND

Hypertension is a stroke risk factor with known disparities in prevalence and management between Black and White patients. We sought to identify if racial differences in presenting blood pressure (BP) during acute ischemic stroke exist.

METHODS AND RESULTS

Adults with acute ischemic stroke presenting to an emergency department within 24 hours of last known normal during study epochs 2005, 2010, and 2015 within the Greater Cincinnati/Northern Kentucky Stroke Study were included. Demographics, histories, arrival BP, National Institutes of Health Stroke Scale score, and time from last known normal were collected. Multivariable linear regression was used to determine differences in mean BP between Black and White patients, adjusting for age, sex, National Institutes of Health Stroke Scale score, history of hypertension, hyperlipidemia, smoking, stroke, body mass index, and study epoch. Of 4048 patients, 853 Black and 3195 White patients were included. In adjusted analysis, Black patients had higher presenting systolic BP (161 mm Hg [95% CI, 159-164] versus 158 mm Hg [95% CI, 157-159], P<0.01), diastolic BP (86 mm Hg [95% CI, 85-88] versus 83 mm Hg [95% CI, 82-84], P<0.01), and mean arterial pressure (111 mm Hg [95% CI, 110-113] versus 108 mm Hg [95% CI, 107-109], P<0.01) compared with White patients. In adjusted subanalysis of patients <4.5 hours from last known normal, diastolic BP (88 mm Hg [95% CI, 86-90] versus 83 mm Hg [95% CI, 82-84], P<0.01) and mean arterial pressure (112 mm Hg [95% CI, 110-114] versus 108 mm Hg [95% CI, 107-109], P<0.01) were also higher in Black patients.

CONCLUSIONS

This population-based study suggests differences in presenting BP between Black and White patients during acute ischemic stroke. Further study is needed to determine whether these differences influence clinical decision-making, outcome, or clinical trial eligibility.

Trends in All-Cause, Cardiovascular, and Noncardiovascular Mortality Among US Adults With Hypertension

BACKGROUND

Death certificate data indicate that hypertension may have increased as a contributing cause of death among US adults. Hypertension is not commonly recorded on death certificates although it contributes to a substantial proportion of cardiovascular disease (CVD) deaths.

METHODS

We estimated changes in all-cause, CVD, and non-CVD mortality over 5 years of follow-up among 4 cohorts of US adults with hypertension using mortality follow-up data from National Health and Nutrition Examination Survey III in 1988 to 1994, and National Health and Nutrition Examination Survey cycles from 1999 to 2000 through 2015 to 2016 (n=20 927). Hypertension was defined as systolic blood pressure ≥140 mm Hg, diastolic blood pressure ≥90 mm Hg, or antihypertensive medication use. Participants were grouped according to the date of their National Health and Nutrition Examination Survey study visit (1988-1994, 1999-2004, 2005-2010, 2011-2016).

RESULTS

There were 2646, 1048, and 1598 all-cause, CVD, and non-CVD deaths, respectively. After age, gender, and race/ethnicity adjustment and compared with the 1988 to 1994 cohort, the hazard ratio of all-cause mortality was 0.88 (95% CI, 0.76-1.01) for the 1999 to 2004 cohort, 0.82 (95% CI, 0.70-0.95) for the 2005 to 2010 cohort, and 0.89 (95% CI, 0.75-1.05) for the 2011 to 2016 cohort (P trend=0.123). The age, gender, and race/ethnicity-adjusted hazard ratios for CVD mortality compared with the 1988 to 1994 cohort were 0.74 (95% CI, 0.60-0.90) for the 1999 to 2004 cohort, 0.61 (95% CI, 0.50-0.74) for the 2005 to 2010 cohort, and 0.57 (95% CI, 0.44-0.74) for the 2011 to 2016 cohort (P trend <0.001). There was no evidence of a change in CVD mortality between the 2005 to 2010 and 2011 to 2016 cohorts (P=0.661). Noncardiovascular mortality did not decline over the study period (P trend=0.145).

CONCLUSIONS

The decline in CVD mortality among US adults with hypertension stalled after 2005 to 2010.

Sherman Lecture: Are We Aiming at the Correct Targets to Reduce Disparities in Stroke Mortality? Celebration, Reflection, and Redirection

Although deaths from stroke have been reduced by 75% in the past 54 years, there has been virtually no reduction in the relative magnitude of Black-to-White disparity in stroke deaths, or the heavier burden of stroke deaths in the Stroke Belt region of the United States. Furthermore, although the rural-urban disparity has decreased in the past decade, this reduction is largely attributable to an increased stroke mortality in the urban areas, rather than reduced stroke mortality in rural areas. We need to focus our search for interventions to reduce disparities on those that benefit the disadvantaged populations, and support this review using relatively recently developed statistical approaches to estimate the magnitude of the potential reduction in the disparities.

Addressing disparities in the global epidemiology of stroke

Stroke is the second leading cause of death and the third leading cause of disability worldwide. Though the burden of stroke worldwide seems to have declined in the past three decades, much of this effect reflects decreases in high-income countries (HICs). By contrast, the burden of stroke has grown rapidly in low-income and middle-income countries (LMICs), where epidemiological, socioeconomic and demographic shifts have increased the incidence of stroke and other non-communicable diseases. Furthermore, even in HICs, disparities in stroke epidemiology exist along racial, ethnic, socioeconomic and geographical lines. In this Review, we highlight the under-acknowledged disparities in the burden of stroke. We emphasize the shifting global landscape of stroke risk factors, critical gaps in stroke service delivery, and the need for a more granular analysis of the burden of stroke within and between LMICs and HICs to guide context-appropriate capacity-building. Finally, we review strategies for addressing key inequalities in stroke epidemiology, including improvements in epidemiological surveillance and context-specific research efforts in under-resourced regions, development of the global workforce of stroke care providers, expansion of access to preventive and treatment services through mobile and telehealth platforms, and scaling up of evidence-based strategies and policies that target local, national, regional and global stroke disparities.

Sleep Apnea and Incident Stroke in a National Cohort of Black and White Adults

BACKGROUND AND OBJECTIVES

Racial/ethnic differences have been documented in the relationship between obstructive sleep apnea (OSA) and stroke incidence, yet racial differences in OSA symptoms or treatment and their relationship with stroke incidence are underexplored and may contribute to stroke disparities. We comprehensively examined OSA symptoms and their relationships to stroke incidence by race/ethnicity.

METHODS

Data were collected from the REasons for Geographic and Racial Differences in Stroke (REGARDS) study, a population-based cohort of Black and White individuals in the United States. Participants free from a stroke diagnosis at baseline were included. Participants self-reported the following: (1) snoring; (2) daytime sleepiness; (3) provider-diagnosed sleep apnea (PDSA); and (4) treatment for PDSA using positive airway pressure (PAP). OSA risk was categorized as high or low based on the Berlin Sleep Questionnaire. Incident stroke was defined as first occurrence of stroke over an average of 12 (SD 3.9) years of follow-up. We report the relationships between snoring, OSA risk, PDSA, PAP therapy use, and incident stroke by race/ethnicity using Cox proportional hazards models after adjusting for demographic and socioeconomic factors and stroke risk factors.

RESULTS

Among the 22,192 participants (mean age [SD] 64.2[9.1] years), 38.1% identified as Black. Overall, snoring was not associated with incident stroke (hazard ratio [HR] 0.98, 95% CI 0.85-1.13). However, among White individuals but not Black individuals, high OSA risk and PDSA were associated with incident stroke (HR 1.22, 95% CI 1.01-1.47; HR 1.33, 95% CI 1.04-1.70, respectively). PAP therapy use among those with PDSA (compared with non-PDSA) was associated with incident stroke in White individuals (HR 1.38, 95% CI 1.05-1.80). PAP therapy use among those with PDSA (compared with those with PDSA without PAP therapy use) was associated with reduced risk of incident stroke in Black (HR 0.39, 95% CI 0.17-0.91) but not White (HR 0.63, 95% CI 0.37-1.10) individuals.

DISCUSSION

White individuals with high OSA risk and those with PDSA with or without PAP therapy use were at increased incident stroke risk, whereas Black individuals reporting PDSA and PAP had reduced incident stroke risk relative to those not using PAP. Future research is needed to understand the mechanisms underlying racial differences in OSA and stroke such as differences in assessment modes and treatment.

Interleukin-6, Diabetes, and Metabolic Syndrome in a Biracial Cohort: The Reasons for Geographic and Racial Differences in Stroke Cohort

OBJECTIVE

Black Americans have a greater risk of type 2 diabetes than White Americans. The proinflammatory cytokine interleukin-6 (IL-6) is implicated in diabetes pathogenesis, and IL-6 levels are higher in Black individuals. This study investigated associations of IL-6 with incident diabetes and metabolic syndrome in a biracial cohort.

RESEARCH DESIGN AND METHODS

The Reasons for Geographic and Racial Differences in Stroke (REGARDS) study enrolled 30,239 Black and White adults age ≥45 years in 2003-2007, with a follow-up ∼9.5 years later. Baseline plasma IL-6 was measured in 3,399 participants at risk of incident diabetes and 1,871 at risk of metabolic syndrome. Relative risk (RR) by IL-6 was estimated with modified Poisson regression for both groups.

RESULTS

Incident diabetes occurred in 14% and metabolic syndrome in 20%; both rates rose across IL-6 quartiles. There was a three-way interaction of IL-6, race, and central adiposity for incident diabetes (P = 8 × 10-5). In Black participants with and without central adiposity, RRs were 2.02 (95% CI 1.00-4.07) and 1.66 (1.00-2.75) for the fourth compared with first IL-6 quartile, respectively. The corresponding RRs were 1.73 (0.92-3.26) and 2.34 (1.17-4.66) in White participants. The pattern was similar for IL-6 and metabolic syndrome.

CONCLUSIONS

Although IL-6 was higher in Black than in White participants and those with central adiposity, the association of IL-6 with diabetes risk was statistically significant only among White participants without central adiposity. The association with metabolic syndrome risk was similarly stronger in low-risk groups. The results support the concept of interventions to lower inflammation in diabetes prevention, but to reduce race disparities, better biomarkers are needed.

Ethnicity-specific blood pressure thresholds based on cardiovascular and renal complications: a prospective study in the UK Biobank

BACKGROUND

The appropriateness of hypertension thresholds for triggering action to prevent cardiovascular and renal complications among non-White populations in the UK is subject to question. Our objective was to establish ethnicity-specific systolic blood pressure (SBP) cutoffs for ethnic minority populations and assess the efficacy of these ethnicity-specific cutoffs in predicting adverse outcomes.

METHODS

We analyzed data from UK Biobank, which included 444,418 participants from White, South Asian, Black Caribbean, and Black African populations with no history of cardiorenal complications. We fitted Poisson regression models with continuous SBP and ethnic groups, using Whites as the referent category, for the composite outcome of atherosclerotic cardiovascular disease, heart failure, and chronic kidney disease. We determined ethnicity-specific thresholds equivalent to the risks observed in Whites at SBP levels of 120, 130, and 140 mm Hg. We adjusted models for clinical characteristics, sociodemographic factors, and behavioral factors. The performance of ethnicity-specific thresholds for predicting adverse outcomes and associated population-attributable fraction (PAF) was assessed in ethnic minority groups.

RESULTS

After a median follow-up of 12.5 years (interquartile range, 11.7-13.2), 32,662 (7.4%) participants had incident composite outcomes. At any given SBP, the predicted incidence rate of the composite outcome was the highest for South Asians, followed by White, Black Caribbean, and Black African. For an equivalent risk of outcomes observed in the White population at an SBP level of 140 mm Hg, the SBP threshold was lower for South Asians (123 mm Hg) and higher for Black Caribbean (156 mm Hg) and Black African (165 mm Hg). Furthermore, hypertension defined by ethnicity-specific thresholds was a stronger predictor and resulted in a larger PAF for composite outcomes in South Asians (21.5% [95% CI, 2.4,36.9] vs. 11.3% [95% CI, 2.6,19.1]) and Black Africans (7.1% [95% CI, 0.2,14.0] vs. 5.7 [95% CI, -16.2,23.5]) compared to hypertension defined by guideline-recommended thresholds.

CONCLUSIONS

Guideline-recommended blood pressure thresholds may overestimate risks for the Black population and underestimate risks for South Asians. Using ethnicity-specific SBP thresholds may improve risk estimation and optimize hypertension management toward the goal of eliminating ethnic disparities in cardiorenal complications.

Hepatocyte growth factor and risk of incident stroke in Black and White Americans in the Reasons for Geographic and Racial Differences in Stroke study

Background

Hepatocyte growth factor (HGF) is a cytokine produced in response to endothelial damage. Higher levels correlate with cardiovascular risk factors, including hypertension and diabetes.

Objectives

We hypothesized that HGF is associated with stroke.

Methods

The Reasons for Geographic And Racial Differences in Stroke (REGARDS) study enrolled 30,239 Black and White Americans aged ≥45 years from 2003 to 2007. In this case-cohort study, after 5.5 years of follow-up, circulating baseline HGF was measured in 557 participants with incident ischemic stroke and in a cohort random sample of 964 participants. Hazard ratios (HRs) per SD log-transformed HGF and by HGF quintile were calculated using Cox proportional hazards models adjusting for stroke risk factors and other correlates of HGF. Differences by race and sex were tested using interaction terms.

Results

Median HGF was 295 (IQR, 209-402) pg/mL. HGF was higher with older age, male sex, prevalent cardiovascular disease, smoking, and warfarin use, but did not differ by race. The adjusted HR of incident ischemic stroke per SD higher baseline HGF (145 pg/mL) was 1.30 (CI, 1.00-1.70), with no difference by sex or race. HGF in the highest (>434 pg/mL) vs lowest quintile (<135 pg/mL) was associated with an adjusted HR of incident stroke of 2.12 (CI, 1.31-3.41).

Conclusion

In the REGARDS study, higher HGF was associated with increased risk of incident ischemic stroke in Black and White adults, with a doubling in risk of HGF in the top quintile compared with the lowest quintile after adjusting for other stroke risk factors.

DECODING STROKE DISPARITIES: ZIP CODES, COLOR CODES, AND EPIGENETIC CODES

Despite decreases in overall stroke incidence and mortality in the United States, racial and ethnic disparities continue unabated. Of note, the long-standing disproportionate burden of stroke on African Americans compared to other racial and ethnic groups persists, and national projections indicate this toll will likely worsen over the next decade. Why have we not been able to bend the stroke disparities curve for African Americans? Well, this is mainly because traditional stroke risk factors, such as hypertension, diabetes, etc., account for just half of the Black vs. non-Hispanic White stroke disparity. As such, there is increasing interest in evaluating understudied factors like upstream social determinants of health, including geography, psychosocial stress, and environmental pollution; identifying potential mediators; and testing multilevel interventions to address them. This paper highlights emerging avenues that may help decode the excess stroke risk in African Americans, focusing on zip codes, color codes, and epigenetic codes.

APOL1 Risk Variants Associate With the Prevalence of Stroke in African American Current and Past Smokers

BACKGROUND

African American smokers have 2.5 times higher risk for stroke compared with nonsmokers (higher than other races). About 50% of the African American population carry 1 or 2 genetic variants (G1 and G2; rare in other races) of the apolipoprotein L1 gene (APOL1). Studies showed these variants may be associated with stroke. However, the role of the APOL1 risk variants in tobacco-related stroke is unknown.

METHODS AND RESULTS

In a cross-sectional study, we examined whether APOL1 risk variants modified the relationship between tobacco smoking and stroke prevalence in 513 African American adults recruited at University of California, San Francisco. Using DNA, plasma, and questionnaires we determined APOL1 variants, smoking status, and stroke prevalence. Using logistic regression models, we examined the association between smoking (ever versus never smokers) and stroke overall, and among carriers of APOL1 risk variants (1 or 2 risk alleles), and noncarriers, separately. Among participants, 41% were ever (current and past) smokers, 54% were carriers of the APOL1 risk variants, and 41 had a history of stroke. The association between smoking and stroke differed by APOL1 genotype (Pinteraction term=0.014). Among carriers, ever versus never smokers had odds ratio (OR) 2.46 (95% CI, 1.08-5.59) for stroke (P=0.034); OR 2.00 (95% CI, 0.81-4.96) among carriers of 1 risk allele, and OR 4.72 (95% CI, 0.62-36.02) for 2 risk alleles. Among noncarriers, smoking was not associated with a stroke.

CONCLUSIONS

Current and past smokers who carry APOL1 G1 and/or G2 risk variants may be more susceptible to stroke among the African American population.

Achieving Equity in Stroke Care and Outcomes: A Comment on an AHA Scientific Statement

Racial disparities in stroke outcomes have been described for over a century. Racial and ethnic inequities in care and disparities in outcomes exist across the continuum of stroke care. In this commentary, I discuss several themes that emerged from the recent article, Strategies to Reduce Racial and Ethnic Inequities in Stroke Preparedness, Care, Recovery, and Risk Factor Control: A Scientific Statement From the American Heart Association. This statement provides a comprehensive overview of interventions aimed at reducing racial and ethnic disparities and highlights gaps in knowledge and research priorities.

The role of caregiving in cognitive function and change: The REGARDS study

Chronic stress is associated with negative health outcomes, including poorer cognition. Some studies found stress from caregiving associated with worse cognitive functioning; however, findings are mixed. The present study examined the relationship between caregiving, caregiving strain, and cognitive functioning. We identified participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study who were family caregivers at baseline assessment and used propensity matching on 14 sociodemographic and health variables to identify matched noncaregivers for comparison. Data included up to 14 years of repeated assessments of global cognitive functioning, learning and memory, and executive functioning. Our results showed that when compared to noncaregivers, caregivers had better baseline scores on global cognitive functioning and word list learning (WLL). Among caregivers, a lot of strain was associated with better WLL and delayed word recall in the unadjusted model only. Caregivers with a lot of strain had higher depressive symptoms but not significantly higher high-sensitivity c-reactive protein (hsCRP) at baseline compared to caregivers with no or some strain after covariate adjustment. Although caregiving can be highly stressful, we found caregiving status and caregiving strain were not associated with cognitive decline. More methodologically rigorous studies are needed, and conclusions that caregiving has negative effects on cognition should be viewed with caution. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Examining the U-shaped relationship of sleep duration and systolic blood pressure with risk of cardiovascular events using a novel recursive gradient scanning model

Background

Observational studies have suggested U-shaped relationships between sleep duration and systolic blood pressure (SBP) with risks of many cardiovascular diseases (CVDs), but the cut-points that separate high-risk and low-risk groups have not been confirmed. We aimed to examine the U-shaped relationships between sleep duration, SBP, and risks of CVDs and confirm the optimal cut-points for sleep duration and SBP.

Methods

A retrospective analysis was conducted on NHANES 2007-2016 data, which included a nationally representative sample of participants. The maximum equal-odds ratio (OR) method was implemented to obtain optimal cut-points for each continuous independent variable. Then, a novel "recursive gradient scanning method" was introduced for discretizing multiple non-monotonic U-shaped independent variables. Finally, a multivariable logistic regression model was constructed to predict critical risk factors associated with CVDs after adjusting for potential confounders.

Results

A total of 26,691 participants (48.66% were male) were eligible for the current study with an average age of 49.43 ± 17.69 years. After adjusting for covariates, compared with an intermediate range of sleep duration (6.5-8.0 h per day) and SBP (95-120 mmHg), upper or lower values were associated with a higher risk of CVDs [adjusted OR (95% confidence interval) was 1.20 (1.04-1.40) for sleep duration and 1.17 (1.01-1.36) for SBP].

Conclusions

This study indicates U-shaped relationships between SBP, sleep duration, and risks of CVDs. Both short and long duration of sleep/higher and lower BP are predictors of cardiovascular outcomes. Estimated total sleep duration of 6.5-8.0 h per day/SBP of 95-120 mmHg is associated with lower risk of CVDs.

Diagnosis and Management of Cardiovascular Risk in Individuals With Spinal Cord Injury: A Narrative Review

More than 16 000 Americans experience spinal cord injury (SCI), resulting in chronic disability and other secondary sequelae, each year. Improvements in acute medical management have increased life expectancy. Cardiovascular disease is a leading cause of death in this population, and seems to occur earlier in individuals with SCI compared with the general population. People with SCI experience a high burden of traditional cardiovascular disease risk factors, including dyslipidemia and diabetes, and demonstrate anatomic, metabolic, and physiologic changes alongside stark reductions in physical activity after injury. They also experience multiple, complex barriers to care relating to disability and, in many cases, compounding effects of intersecting racial and socioeconomic health inequities. Given this combination of risk factors, some investigators have proposed that people with SCI are at increased risk for cardiovascular disease, beyond that associated with traditional risk factors, and SCI could be considered a risk-enhancing factor, analogous to other risk-enhancing factors defined by the 2019 American Heart Association/American College of Cardiology Primary Prevention Guidelines. However, more research is needed in this population to clarify the role of traditional risk factors, novel risk factors, health care access, social determinants of health, and intersectionality of disability, race, and socioeconomic status. There is an urgent need for primary care physicians and cardiologists to have awareness of the importance of timely diagnosis and management of cardiac risk factors for people with SCI.

Gut microbiota-associated metabolites and risk of ischemic stroke in REGARDS

Several metabolite markers are independently associated with incident ischemic stroke. However, prior studies have not accounted for intercorrelated metabolite networks. We used exploratory factor analysis (EFA) to determine if metabolite factors were associated with incident ischemic stroke. Metabolites (n = 162) were measured in a case-control cohort nested in the REasons for Geographic and Racial Differences in Stroke (REGARDS) study, which included 1,075 ischemic stroke cases and 968 random cohort participants. Cox models were adjusted for age, gender, race, and age-race interaction (base model) and further adjusted for the Framingham stroke risk factors (fully adjusted model). EFA identified fifteen metabolite factors, each representing a well-defined metabolic pathway. Of these, factor 3, a gut microbiome metabolism factor, was associated with an increased risk of stroke in the base (hazard ratio per one-unit standard deviation, HR = 1.23; 95%CI = 1.15-1.31; P = 1.98 × 10-10) and fully adjusted models (HR = 1.13; 95%CI = 1.06-1.21; P = 4.49 × 10-4). The highest tertile had a 45% increased risk relative to the lowest (HR = 1.45; 95%CI = 1.25-1.70; P = 2.24 × 10-6). Factor 3 was also associated with the Southern diet pattern, a dietary pattern previously linked to increased stroke risk in REGARDS (β = 0.11; 95%CI = 0.03-0.18; P = 8.75 × 10-3). These findings highlight the role of diet and gut microbial metabolism in relation to incident ischemic stroke.

Alpha globin gene copy number and incident ischemic stroke risk among Black Americans

Introduction

People with African ancestry have greater stroke risk and greater heritability of stroke risk than people of other ancestries. Given the importance of nitric oxide (NO) in stroke, and recent evidence that alpha globin restricts nitric oxide release from vascular endothelial cells, we hypothesized that alpha globin gene (HBA) deletion would be associated with reduced risk of incident ischemic stroke.

Methods

We evaluated 8,947 participants self-reporting African ancestry in the national, prospective Reasons for Geographic And Racial Differences in Stroke (REGARDS) cohort. Incident ischemic stroke was defined as non-hemorrhagic stroke with focal neurological deficit lasting ≥ 24 hours confirmed by the medical record or focal or non-focal neurological deficit with positive imaging confirmed with medical records. Genomic DNA was analyzed using droplet digital PCR to determine HBA copy number. Multivariable Cox proportional hazards regression was used to estimate the hazard ratio (HR) of HBA copy number on time to first ischemic stroke.

Results

Four-hundred seventy-nine (5.3%) participants had an incident ischemic stroke over a median (IQR) of 11.0 (5.7, 14.0) years' follow-up. HBA copy number ranged from 2 to 6: 368 (4%) -α/-α, 2,480 (28%) -α/αα, 6,014 (67%) αα/αα, 83 (1%) ααα/αα and 2 (<1%) ααα/ααα. The adjusted HR of ischemic stroke with HBA copy number was 1.04; 95%CI 0.89, 1.21; p = 0.66.

Conclusions

Although a reduction in HBA copy number is expected to increase endothelial nitric oxide signaling in the human vascular endothelium, HBA copy number was not associated with incident ischemic stroke in this large cohort of Black Americans.

Association of Circulating Metabolites With Racial Disparities in Hypertension and Stroke in the REGARDS Study

BACKGROUND AND OBJECTIVES

In the United States, the risk of stroke is greater among Black compared with that among White individuals. However, the reasons for the difference in stroke incidence are not fully elucidated. We aimed to identify metabolites that account for higher prevalent hypertension and incident ischemic stroke among Black adults.

METHODS

We used a stroke case cohort nested within the REasons for Geographic and Racial Differences in Stroke (REGARDS) study. Targeted metabolomic profiling of 162 plasma metabolites was performed by liquid chromatography-tandem mass spectrometry. We identified metabolites that were associated with prevalent hypertension and incident ischemic stroke and mediated the relationship between hypertension and ischemic stroke by weighted logistic regression, Cox proportional hazard model, and inverse odds ratio weighting mediation analysis.

RESULTS

Incident ischemic stroke cases adjudicated through April 1, 2019 (n = 1,075) were included in the study. The random cohort sample was derived from the full cohort using stratified sampling (n = 968). Among 162 metabolites, gluconic acid was associated with prevalent hypertension in Black adults (odds ratio [OR] 1.86, 95% CI 1.39-2.47, p = 2.58 × 10-5) but not in White adults (OR 1.00, 95% CI 0.80-1.24, p = 0.97; p for interaction = 4.57 × 10-4). Gluconic acid also demonstrated an association with incident ischemic stroke among Black participants (hazard ratio [HR] 1.53, 95% CI 1.28-1.81, p = 1.76 × 10-6) but not White participants (HR 1.16, 95% CI 1.00-1.34, p = 0.057; p for interaction = 0.019). In mediation analysis, gluconic acid mediated 25.4% (95% CI 4.1%-46.8%, p = 0.02) of the association between prevalent hypertension and incident ischemic stroke among Black individuals. Specific socioeconomic factors were linked to elevated gluconic acid level among Black adults in multivariable analysis, including a Southern dietary pattern (β = 0.18, 95% CI 0.08-0.28, p < 0.001), lower educational attainment (β = 0.45, 95% CI 0.19-0.72, p = 0.001), and a lack of exercise (β = 0.26, 95% CI 0.01-0.51, p = 0.045).

DISCUSSION

Gluconic acid is associated with prevalent hypertension and incident ischemic stroke and mediates the relationship between hypertension and ischemic stroke in Black but not White adults. Gluconic acid is a biomarker that is associated with social determinants of health including a Southern diet, low educational attainment, and low physical activity.

Alpha globin gene copy number and incident ischemic stroke risk among Black Americans

Introduction

People with African ancestry have greater stroke risk and greater heritability of stroke risk than people of other ancestries. Given the importance of nitric oxide (NO) in stroke, and recent evidence that alpha globin restricts nitric oxide release from vascular endothelial cells, we hypothesized that alpha globin gene ( HBA) deletion would be associated with reduced risk of incident ischemic stroke.

Methods

We evaluated 8,947 participants self-reporting African ancestry in the national, prospective Reasons for Geographic And Racial Differences in Stroke (REGARDS) cohort. Incident ischemic stroke was defined as non-hemorrhagic stroke with focal neurological deficit lasting ≥ 24 hours confirmed by the medical record or focal or non-focal neurological deficit with positive imaging confirmed with medical records. Genomic DNA was analyzed using droplet digital PCR to determine HBA copy number. Multivariable Cox proportional hazards regression was used to estimate the hazard ratio (HR) of HBA copy number on time to first ischemic stroke.

Results

Four-hundred seventy-nine (5.3%) participants had an incident ischemic stroke over a median (IQR) of 11.0 (5.7, 14.0) years' follow-up. HBA copy number ranged from 2 to 6: 368 (4%) -α/-α, 2,480 (28%) -α/αα, 6,014 (67%) αα/αα, 83 (1%) ααα/αα and 2 (<1%) ααα/ααα. The adjusted HR of ischemic stroke with HBA copy number was 1.04; 95%CI 0.89, 1.21; p = 0.66.

Conclusions

Although a reduction in HBA copy number is expected to increase endothelial nitric oxide signaling in the human vascular endothelium, HBA copy number was not associated with incident ischemic stroke in this large cohort of Black Americans.

APOL1 Risk Variants Associate with the Prevalence of Stroke in African American Current and Past Smokers

Introduction

Among African Americans, tobacco smokers have 2.5 times higher risk for stroke compared to non-smokers; the tobacco-related stroke risk being higher than in other races/ethnicities. About one half of African Americans carry at least one of two genetic variants (G1 and G2; rare in other races) of apolipoprotein L1 (apoL1), a component of high-density lipoproteins. Several studies showed APOL1 G1/G2 risk variants associate with stroke. However, the role of APOL1 variants in tobacco-related stroke is unknown.

Methods

In a cross-sectional study, we examined whether APOL1 risk variants modify the relationship between smoking and stroke in 513 African American adults (median age 58 years, 52% female) recruited through the University of California, San Francisco Lipid Clinic. Using DNA, plasma, and questionnaires we determined APOL1 variants, smoking status, and history of stroke. Using unstratified and stratified multivariable logistic regression models we examined the association between smoking history (ever smokers vs. never smokers) and odds of stroke overall, and among carriers of risk variants and non-carriers, separately.

Results

Among participants, 41% were ever (current and past) smokers, 54% were carriers of the APOL1 risk variant, and 41 have had stroke. In all stroke cases, where full medical records were available, stroke types were determined to be an ischemic, and not hemorrhagic, stroke. The association of smoking history and stroke differed by APOL1 genotype status in the unstratified model (Pinteraction term=0.016). Among carriers of risk variants, ever smokers had odds ratio (OR) =2.88 for stroke compared to never smokers (P=0. 0.038). The OR for stroke comparing ever vs. never smokers showed a dose-response trend among carriers of one risk allele of 2.35 and two risk alleles of 4.96. Among non-carriers, smoking history was not associated with a stroke.

Conclusion

In conclusion, current and past smokers who carry APOL1 G1 and/or G2 risk variants may be more susceptible to stroke, in particular ischemic stroke, among African Americans.

Exploring Racial and Ethnic Differences in Arterial Stiffness Among Youth and Young Adults With Type 1 Diabetes

Background We examined arterial stiffness in individuals with type 1 diabetes, and explored whether differences between Hispanic, non-Hispanic Black (NHB), and non-Hispanic White (NHW) individuals were attributable to modifiable clinical and social factors. Methods and Results Participants (n=1162; 22% Hispanic, 18% NHB, and 60% NHW) completed 2 to 3 research visits from ≈10 months to ≈11 years post type 1 diabetes diagnosis (mean ages of ≈9 to ≈20 years, respectively) providing data on socioeconomic factors, type 1 diabetes characteristics, cardiovascular risk factors, health behaviors, quality of clinical care, and perception of clinical care. Arterial stiffness (carotid-femoral pulse wave velocity [PWV], m/s) was measured at ≈20 years of age. We analyzed differences in PWV by race and ethnicity, then explored the individual and combined impact of the clinical and social factors on these differences. PWV did not differ between Hispanic (adjusted mean 6.18 [SE 0.12]) and NHW (6.04 [0.11]) participants after adjustment for cardiovascular risks (P=0.06) and socioeconomic factors (P=0.12), or between Hispanic and NHB participants (6.36 [0.12]) after adjustment for all factors (P=0.08). PWV was higher in NHB versus NHW participants in all models (all P<0.001). Adjustment for modifiable factors reduced the difference in PWV by 15% for Hispanic versus NHW participants; by 25% for Hispanic versus NHB; and by 21% for NHB versus NHW. Conclusions Cardiovascular and socioeconomic factors explain one-quarter of the racial and ethnic differences in PWV of young people with type 1 diabetes, but NHB individuals still experienced greater PWV. Exploration of pervasive inequities potentially driving these persistent differences is needed.

Sharing Perspectives in African American Communities to Reduce Stroke Risk Through Community Listening Circles

PURPOSE

To build trust and explore community perception on stroke disparities as well as barriers and strengths to stroke prevention.

DESIGN

Mixed methods study.

METHODS

A convenience sample (n = 54) of African Americans responded to questionnaires and participated in focus groups.

FINDINGS

Although a majority of participants had some knowledge of stroke warning signs and risk factors, there were misconceptions identified through the Community Listening Circles (CLCs). Misconceptions about stroke were identified. Six key themes emerged.

CONCLUSIONS

Focus groups provided a better understanding of stroke perception.

CLINICAL EVIDENCE

Community health nurses may be able to use this information to provide care appropriately.

Telehealth Trials to Address Health Equity in Stroke Survivors

Telehealth has seen rapid expansion into chronic care management in the past 3 years because of the COVID-19 pandemic. Telehealth for acute care management has expanded access to equitable stroke care to many patients over the past two decades, but there is limited evidence for its benefit for addressing disparities in the chronic care of patients living with stroke. In this review, we discuss advantages and disadvantages of telehealth use for the outpatient management of stroke survivors. Further, we explore opportunities and potential barriers for telehealth in addressing disparities in stroke outcomes related to various social determinants of health. We discuss two ongoing large randomized trials that are utilizing telehealth and telemonitoring for management of blood pressure in diverse patient populations. Finally, we discuss strategies to address barriers to telehealth use in patients with stroke and in populations with adverse social determinants of health.

Age and Five-Year Outcomes After Carotid Artery Stenting in Symptomatic Carotid Stenosis: A Retrospective Cohort Study

Background

Several clinical trials have reported that periprocedural risk of carotid artery stenting (CAS) increase with age. China is experiencing one of the most rapid transitions to an aging society, while the clinical outcomes of CAS in real-world China are still limited. The study aimed to compare the periprocedural and an extending 5-year event rates between younger and older patients treated by CAS to testify the safety of CAS in older patients in China.

Methods

This is a single center, retrospective cohort study. Symptomatic patients who underwent CAS from Nov 2011 to June 2014 were retrospectively included in this study, The population was divided into two age groups: <70 and ≥70. The main primary endpoint was stroke, myocardial infarction or death occurring at 30 days, or ipsilateral stroke over 5-year after stenting.

Results

A total of 103 symptomatic patients (<70: 68%; ≥70: 32%) with CAS included in the study. During the 30-day period, the rate of primary outcome was 1.0% with only one stroke in patients younger than 70 years old ( P = 1.000). After five years, the rate of primary outcome was low (10.9%, 10/92) despite some of the patients had major stroke or underwent bilateral C1 stenting. There was no significant difference in the 5-year rates of the primary outcome between the young and old groups (12.3% vs 7.4%, P = .718). Kaplan-Meier estimates of the proportion of study participants with a primary endpoint showed that there was no significant age-dependent difference of the stroke and death outcome in symptomatic patients.

Conclusions

Age (<70 vs ≥ 70) had no influence on the risk of stroke or death in symptomatic patients either in the short or long term. CAS is an optimal treatment for older patients with cervical carotid artery stenosis, and CAS was safe for those with major stroke or bilateral C1 stenting.

Allostatic load predicts racial disparities in intracerebral hemorrhage cognitive outcomes

A large portion of stroke disparities remains unexplained, even after adjusting for demographic, comorbidity, and health care access variables. There is a critical need to close this knowledge gap by investigating novel factors that may contribute to stroke disparities. Allostatic load (AL) is the lifetime adverse physiologic impact of needing to adjust to socially structured stressors such as racism. AL has been shown to increase health vulnerability and worsen outcomes in marginalized populations. We sought to assess the differential impact of AL on cognitive outcomes post intracerebral hemorrhage (ICH) across race-ethnicity. The Intracerebral Hemorrhage Outcomes Project (ICHOP) prospectively collected data from patients presenting to Columbia Medical Center with ICH from 3/2009 to 5/2016. Data included demographics, stroke scores, labs, complications, neuroimaging, medical history, and discharge data. Five markers of AL (HbA1c, WBC, SBP, HR, ALB) were obtained. An AL score was generated by summing the elements in each patient that fell outside normal ranges, with AL score ranging 0–5. A linear regression model, adjusted for stroke severity and ICH volumes, was used to evaluate the relationship between AL and Modified Telephone Interview for Cognitive Status (TICS-m) at discharge, stratified by race-ethnicity. Among 248 white, 195 black, and 261 Hispanic ICH patients, neither mean AL nor mean TICS differed by race/ethnicity (p = 0.51, p = 0.79 respectively). In the overall cohort AL did not predict TICS at discharge (Beta -1.0, SE 1.1, p = 0.353). In Whites (beta 1.18, SE 2.5, p = 0.646) and Hispanics (beta -0.95, SE 1.6, p = 0.552) AL was not associated with TICS at discharge. In Black patients, higher AL was associated with a decrease in TICS at discharge (beta -3.2, SE 1.5, p = 0.049). AL is an important determinant of post ICH outcomes for certain minority populations. AL may explain some of the unexplained health disparities in stroke populations.

Supplementation with omega-3 or omega-6 fatty acids attenuates platelet reactivity in postmenopausal women

Postmenopausal women are at increased risk for a cardiovascular event due to platelet hyperactivity. There is evidence suggesting that ω-3 polyunsaturated fatty acids (PUFAs) and ω-6 PUFAs have cardioprotective effects in these women. However, a mechanistic understanding of how these fatty acids regulate platelet function is unknown. In this study, we supplemented postmenopausal women with fish oil (ω-3 fatty acids) or evening primrose oil (ω-6 fatty acids) and investigated the effects on their platelet activity. The effects of fatty acid supplementation on platelet aggregation, dense granule secretion, and activation of integrin αIIbβ3 at basal levels and in response to agonist were tested in postmenopausal women following a supplementation and washout period. Supplementation with fish oil or primrose oil attenuated the thrombin receptor PAR4-induced platelet aggregation. Supplementation with ω-3 or ω-6 fatty acids decreased platelet dense granule secretion and attenuated basal levels of integrin αIIbβ3 activation. Interestingly, after the washout period following supplementation with primrose oil, platelet aggregation was similarly attenuated. Additionally, for either treatment, the observed protective effects post-supplementation on platelet dense granule secretion and basal levels of integrin activation were sustained after the washout period, suggesting a long-term shift in platelet reactivity due to fatty acid supplementation. These findings begin to elucidate the underlying mechanistic effects of ω-3 and ω-6 fatty acids on platelet reactivity in postmenopausal women. Hence, this study supports the beneficial effects of fish oil or primrose oil supplementation as a therapeutic intervention to reduce the risk of thrombotic events in postmenopausal women. https://clinicaltrials.gov/ct2/show/NCT02629497.

Blood Pressure Control Among US Adults, 2009 to 2012 Through 2017 to 2020

BACKGROUND

The National Health and Nutrition Examination Survey data indicate that the proportion of US adults with hypertension that had controlled blood pressure (BP) declined from 2013 to 2014 through 2017 to 2018. We analyzed data from National Health and Nutrition Examination Survey 2009 to 2012, 2013 to 2016, and 2017 to 2020 to confirm this finding.

METHODS

Hypertension was defined as systolic BP ≥140 mm Hg or diastolic BP ≥90 mm Hg or antihypertensive medication use. BP control among those with hypertension was defined as systolic BP <140 mm Hg and diastolic BP <90 mm Hg.

RESULTS

The age-adjusted prevalence of hypertension was 31.5% (95% CI, 30.3%-32.8%), 32.0% (95% CI, 30.6%-33.3%), and 32.9% (95% CI, 31.0%-34.7%) in 2009 to 2012, 2013 to 2016, and 2017 to 2020, respectively (P trend=0.218). The age-adjusted prevalence of hypertension increased among non-Hispanic Asian adults from 27.0% in 2011 to 2012 to 33.5% in 2017 to 2020 (P trend=0.003). Among Hispanic adults, the age-adjusted prevalence of hypertension increased from 29.4% in 2009 to 2012 to 33.2% in 2017 to 2020 (P trend=0.029). In 2009 to 2012, 2013 to 2016, and 2017 to 2020, 52.8% (95% CI, 50.0%-55.7%), 51.3% (95% CI, 47.9%-54.6%), and 48.2% (95% CI, 45.7%-50.8%) of US adults with hypertension had controlled BP (P trend=0.034). Among US adults taking antihypertensive medication, 69.9% (95% CI, 67.8%-72.0%), 69.3% (95% CI, 66.6%-71.9%), and 67.7% (95% CI, 65.2%-70.3%) had controlled BP in 2009 to 2012, 2013 to 2016, and 2017 to 2020, respectively (P trend=0.189). Among all US adults with hypertension and those taking antihypertensive medication, a decline in BP control between 2009 to 2012 and 2017 to 2020 occurred among those ≥75 years, women, and non-Hispanic black adults.

CONCLUSIONS

These data confirm that the proportion of US adults with hypertension who have controlled BP has declined.

A Systematic Review and Meta-Analysis of the Associations between Immigration Status and Stroke Incidence and Mortality

Methods

We thoroughly searched PubMed, Embase, and MEDLINE databases for the literature on stroke risk for immigrants and host populations by January 2022. Fourteen relevant cohort studies from eight countries met the inclusion criteria, and their data were included in this meta-analysis. Heterogeneity and publication bias were assessed.

Results

The results showed that the immigrant groups suffered from a lower incidence rate of stroke compared with the host populations (HR = 0.81, 95% CI 0.71-0.91, P = 0.001), but there was nonsignificant higher mortality of stroke in immigrants (HR = 1.07; 95% CI 0.84-1.36). However, the pooled adjusted incidence HR reduced to 0.67 (95% CI 0.60-0.75) after adjustment for publication bias. Immigrants had a lower stroke incidence compared to long-term residents, but the association varied with the country of origin, socioeconomic status, residence (urban vs. rural), and comorbid conditions. Discussion. The present systematic review and meta-analysis implicated that stroke risks are different for immigrants and the host populations; therefore, this knowledge may be useful for developing targeted stroke prevention strategies.

Molecular mechanisms underlying some major common risk factors of stroke

Ischemic and hemorrhagic strokes are the most common known cerebrovascular disease which can be induced by modifiable and non-modifiable risk factors. Age and race are the most common non-modifiable risk factors of stroke. However, hypertension, diabetes, obesity, dyslipidemia, physical inactivity, and cardiovascular disorders are major modifiable risk factors. Understanding the molecular mechanism mediating each of these risk factors is expected to contribute significantly to reducing the risk of stroke, preventing neural damage, enhancing rehabilitation, and designing suitable treatments. Abnormalities in the structure of the blood-brain barrier and blood vessels, thrombosis, vasoconstriction, atherosclerosis, reduced cerebral blood flow, neural oxidative stress, inflammation, and apoptosis, impaired synaptic transmission, excitotoxicity, altered expression/activities of many channels and signaling proteins are the most knows mechanisms responsible for stroke induction. However, the molecular role of risk factors in each of these mechanisms is not well understood and requires a lot of search and reading. This review was designed to provide the reader with a single source of information that discusses the current update of the prevalence, pathophysiology, and all possible molecular mechanisms underlying some major risk factors of stroke namely, hypertension, diabetes mellitus, dyslipidemia, and lipid fraction, and physical inactivity. This provides a full resource for understanding the molecular effect of each of these risk factors in stroke.

Associations of Clinical and Social Risk Factors With Racial Differences in Premature Cardiovascular Disease

BACKGROUND

Racial differences in cardiovascular disease (CVD) are likely related to differences in clinical and social factors. The relative contributions of these factors to Black-White differences in premature CVD have not been investigated.

METHODS

In Black and White adults aged 18 to 30 years at baseline in the CARDIA study (Coronary Artery Risk Development in Young Adults), the associations of clinical, lifestyle, depression, socioeconomic, and neighborhood factors across young adulthood with racial differences in incident premature CVD were evaluated in sex-stratified, multivariable-adjusted Cox proportional hazards models using multiply imputed data assuming missing at random. Percent reduction in the β estimate (log-hazard ratio [HR]) for race quantified the contribution of each factor group to racial differences in incident CVD.

RESULTS

Among 2785 Black and 2327 White participants followed for a median 33.9 years (25th-75th percentile, 33.7-34.0), Black (versus White) adults had a higher risk of incident premature CVD (Black women: HR, 2.44 [95% CI, 1.71-3.49], Black men: HR, 1.59 [1.20-2.10] adjusted for age and center). Racial differences were not statistically significant after full adjustment (Black women: HR, 0.91 [0.55-1.52], Black men: HR 1.02 [0.70-1.49]). In women, the largest magnitude percent reduction in the β estimate for race occurred with adjustment for clinical (87%), neighborhood (32%), and socioeconomic (23%) factors. In men, the largest magnitude percent reduction in the β estimate for race occurred with an adjustment for clinical (64%), socioeconomic (50%), and lifestyle (34%) factors.

CONCLUSIONS

In CARDIA, the significantly higher risk for premature CVD in Black versus White adults was statistically explained by adjustment for antecedent multilevel factors. The largest contributions to racial differences were from clinical and neighborhood factors in women, and clinical and socioeconomic factors in men.

Nucleosides Associated With Incident Ischemic Stroke in the REGARDS and JHS Cohorts

BACKGROUND AND OBJECTIVES

Both genetic and environmental factors contribute to stroke risk. We sought to identify novel metabolites associated with incident stroke in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort and determine whether they reflected genetic or environmental variation.

METHODS

This was a stroke case-cohort observational study nested in REGARDS. Cases were defined as incident stroke and metabolomic profiles were compared to a randomly selected control cohort. In baseline plasma samples, 162 metabolites were measured using liquid chromatography-tandem mass spectrometry. Cox proportional hazards models were adjusted for age, sex, race, and age by race in the base model. Fully adjusted models included traditional stroke risk factors. Mediation analyses conducted for these stroke risk factors used the metabolite as mediator. Genome-wide associations with the leading candidate metabolites were calculated using array data. Replication analyses in the Jackson Heart Study (JHS) were conducted using random effects meta-analysis.

RESULTS

There were 2,043 participants who were followed over an average period of 7.1 years, including 1,075 stroke cases and 968 random controls. Nine metabolites were associated with stroke in the base model, 8 of which were measured and remained significant in meta-analysis with JHS. In the fully adjusted model in REGARDS, guanosine (hazard ratio [HR] 1.34, 95% CI 1.18-1.53; p = 7.26 × 10^-6) and pseudouridine (HR 1.28, 95% CI 1.13-1.45; p = 1.03 × 10^-4) were associated with incident ischemic stroke following Bonferroni adjustment. Guanosine also partially mediated the relationship between hypertension and stroke (17.6%) and pseudouridine did not mediate any risk factor. Genome-wide association analysis identified loci rs34631560 and rs34631560 associated with pseudouridine, but these did not explain the association of pseudouridine with stroke.

DISCUSSION

Guanosine and pseudouridine are nucleosides associated with incident ischemic stroke independently of other risk factors. Genetic and mediation analyses suggest that environmental exposures rather than genetic variation link nucleoside levels to stroke risk.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that guanosine and pseudouridine are associated with incident stroke.

Utilizing Implementation Science to Bridge Cerebrovascular Health Disparities: a Local to Global Perspective

PURPOSE OF REVIEW

Stroke is a prime example of a medical disorder whose incidence, prevalence, and outcomes are strongly characterized by health disparities across the globe. This scoping literature review seeks to depict how implementation science could be utilized to advance health equity in the prevention, acute treatment, and post-acute management of stroke in the underserved regions of high-income countries as well as in all low-income countries.

RECENT FINDINGS

A major reason for the persisting and widening cerebrovascular disease disparities is that evidence-based stroke prevention and treatment interventions have been differentially translated (if at all) to various populations and settings. The field of implementation science is endowed with frameworks, theories, methodological approaches, and outcome measures, including equity indices, which could be harnessed to facilitate the translation of evidence-based interventions into clinical practice for underserved and vulnerable communities. Encouragingly, there are several novel frameworks, which eminently merge implementation science constructs with health equity determinants, thereby opening up key opportunities to bridge burgeoning worldwide gaps in cerebrovascular health equity.

Age, Sex, Race/Ethnicity, and Income Patterns in Ideal Cardiovascular Health Among Adolescents and Adults in the U.S

INTRODUCTION

Ideal cardiovascular health is present in <50% of children and <1% of adults, yet its prevalence from adolescence through adulthood has not been fully evaluated. This study characterizes the association of age with ideal cardiovascular health and compares these associations across sex, race/ethnicity, and SES subgroups.

METHODS

This study, conducted in 2020, analyzed adolescents and adults aged 12-79 years from the cross-sectional National Health and Nutrition Examination Survey 2005-2016 (N=38,706). Polynomial models were used to model the association of age with ideal cardiovascular health, defined using the American Heart Association's Life's Simple 7 criteria (scales 0-14, with higher values indicating better cardiovascular health).

RESULTS

Mean cardiovascular health was lower with increasing age, starting in early adolescence and dropping to a nadir by age 60 years before stabilizing. At age 20 years, only 45% of adults had ideal cardiovascular health (≥5 ideal cardiovascular health metrics), and >50% of adults had poor cardiovascular health (≤2 ideal cardiovascular health metrics) at age 53 years. Women had higher mean cardiovascular health than men in early life but lower mean cardiovascular health from age 60 years onward. Mean cardiovascular health scores were highest for non-Hispanic White and higher-income adults and lowest for non-Hispanic Black and low-income adults across all ages. Mean cardiovascular health scores fell from intermediate to poor levels approximately 30 years earlier for non-Hispanic Black than for non-Hispanic White adults and approximately 35 years earlier for low-income adults than in higher-income adults.

CONCLUSIONS

Cardiovascular health scores are lower with increasing age from early adolescence through adulthood. Race/ethnicity and income disparities in cardiovascular health are observed at young ages and are more profound at older ages.

Pro-neurotensin/Neuromedin N and Hypertension Risk: A Prospective Study

BACKGROUND

Neurotensin, a neuropeptide with direct cardiac effects, has been associated with prospective risk of hypertension-related conditions through measurement of its precursor, pro-neurotensin/neuromedin N (pro-NT/NMN). Its association with incident hypertension has not been evaluated.

METHODS

From 2003 to 2007, the REasons for Geographic And Racial Differences in Stroke (REGARDS) study enrolled 30,239 Black or White adults age ≥45. Pro-NT/NMN was measured in 1,692 participants without baseline hypertension (self-reported antihypertensive use or blood pressure ≥140/90 mm Hg) who underwent follow-up assessment in 2013-2016. A sensitivity analysis was conducted using a lower threshold (≥130/80 mm Hg) to define hypertension. Three robust Poisson regression models were fitted to risk of incident hypertension, adding demographics, cardiometabolic risk factors, and dietary covariates.

RESULTS

Six hundred and fourteen participants developed hypertension over 9.4 years of follow-up. Pro-NT/NMN ranged from 14 to 1,246 pmol/l, with median [interquartile range] 154 [112, 206] pmol/l. Pro-NT/NMN was not associated with hypertension overall (fully adjusted incidence rate ratio per SD increment log pro-NT/NMN 1.03, 95% confidence interval 0.95-1.11). Results of sensitivity analysis did not differ substantially.

CONCLUSIONS

Baseline pro-NT/NMN was not associated with incident hypertension. This may be a result of neurotensin's long-term interactions with other molecular regulators of blood pressure, such as the renin-angiotensin-aldosterone system.

Health Disparities: Research That Matters

Health advances have not benefited all people equally. Health equity remains an aspirational goal, but research that enhances health equity is the highest priority at the National Institutes of Health. Here, we propose a call to action and outline current National Institutes of Health programs that aim to eliminate health disparities both broadly and in high priority areas. Discussed topics include stroke as an indicator of broad health inequity, challenges, and opportunities in health disparities research, the need to diversify the research workforce, and the ongoing efforts and struggles to establish trust with disadvantaged communities during the COVID-19 pandemic.

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.

Self-Reported Race as a Social Determinant of Stroke Risk in Observational Versus Clinical Trial Datasets

OBJECTIVES

Self-reported Black (SRB) Americans are approximately twice as likely to have a stroke as self-reported White (SRW) Americans. While social determinants of health and vascular risk factors account for some of the disparity, half the increased risk remains unexplained and may be related to unmeasured real-world factors of the racialized experience.

MATERIALS

and Methods In this cohort study, we compared SRB and SRW participants in the Systolic Blood Pressure Intervention Trial (SPRINT) to the same groups in the observational Atherosclerosis Risk in Communities (ARIC) study to evaluate if clinical trial participation mitigates disparities in stroke risk. We set the ARIC baseline at visit 4 and excluded participants with prior stroke to create an ARIC cohort similar in age to SPRINT participants. The study outcome was incident primary stroke. We report hazard ratios from Cox models and inverse-probability weighted Cox models with propensity score matching on participant age, sex, diabetes, atrial fibrillation, and smoking.

RESULTS

We included 10,094 patients from ARIC and 8,869 from SPRINT, of which 26.1% were SRB. The risk of stroke between SRW participants in SPRINT versus ARIC was not significantly different (IPW-Weighted HR 0.78 [0.52-1.19]). SRB ARIC participants were twice as likely to have a stroke as SRW ARIC participants (IPW-Weighted HR = 1.96 [1.41-2.71]). However, SRB SPRINT participants did not have higher stroke risk compared to SRW SPRINT or ARIC participants (IPW-Weighted HR 0.99 [0.68--1.77] and 0.95 [.57-1.59], respectively). SRB SPRINT participants in the intensive BP control group had a lower risk of stroke compared to SRB ARIC participants (IPW-Weighted HR = 0.39 [0.20-0.75]).

CONCLUSIONS

SRB race, compared to SRW race, is associated with an increase in primary stroke risk in the ARIC study but not in the SPRINT trial. The absence of the racial disparity in stroke incidence in SPRINT indicates that aspects of the disparity are modifiable. Population-based interventions that test this hypothesis deserve further attention.

Biomarkers as MEDiators of racial disparities in risk factors (BioMedioR): Rationale, study design, and statistical considerations

PURPOSE

Relative to White adults, Black adults have a substantially higher prevalence of hypertension and diabetes, both key risk factors for stroke, cardiovascular disease, cognitive impairment, and dementia. Blood biomarkers have shown promise in identifying contributors to racial disparities in many chronic diseases.

METHODS

We outline the study design and related statistical considerations for a nested cohort study, the Biomarker Mediators of Racial Disparities in Risk Factors (BioMedioR) study, within the 30,239-person biracial REasons for Geographic And Racial Differences in Stroke (REGARDS) study (2003-present). Selected biomarkers will be assessed for contributions to racial disparities in risk factor development over median 9.4 years of follow-up, with initial focus on hypertension, and diabetes. Here we outline study design decisions and statistical considerations for the sampling of 4,400 BioMedioR participants.

RESULTS

The population for biomarker assessment was selected using a random sample study design balanced across race and sex to provide the optimal opportunity to describe association of biomarkers with the development of hypertension and diabetes. Descriptive characteristics of the BioMedioR sample and analytic plans are provided for this nested cohort study.

CONCLUSIONS

This nested biomarker study will examine pathways with the target to help explain racial differences in hypertension and diabetes incidence.

Social Determinants of Health Among Non-Elderly Adults With Stroke in the United States

OBJECTIVE

To examine the association of social determinants of health (SDOH) on prevalence of stroke in non-elderly adults (<65 years of age).

METHODS

We used the National Health Interview Survey (2013-2017) database. The study population was stratified into younger (<45 years of age) and middle age (45 to 64 years of age) adults. For each individual, an SDOH aggregate score was calculated representing the cumulative number of individual unfavorable SDOH (present vs absent), identified from 39 subcomponents across five domains (economic stability, neighborhood, community and social context, food, education, and health care system access) and divided into quartiles (quartile 1, most favorable; quartile 4, most unfavorable). Multivariable models tested the association between SDOH score quartiles and stroke.

RESULTS

The age-adjusted prevalence of stroke was 1.4% in the study population (n=123,631; 58.2% (n=71,956) in patients <45 years of age). Young adults reported approximately 20% of all strokes. Participants with stroke had unfavorable responses to 36 of 39 SDOH; nearly half (48%) of all strokes were reported by participants in the highest SDOH score quartile. A stepwise increase in age-adjusted stroke prevalence was observed across increasing quartiles of SDOH (first, 0.6%; second, 0.9%; third, 1.4%; and fourth, 2.9%). After accounting for demographics and cardiovascular disease risk factors, participants in the fourth vs first quartile had higher odds of stroke (odds ratio, 2.78; 95% CI, 2.25 to 3.45).

CONCLUSION

Nearly half of all non-elderly individuals with stroke have an unfavorable SDOH profile. Standardized assessment of SDOH risk burden may inform targeted strategies to mitigate disparities in stroke burden and outcomes in this population.

Awareness of the risk factors of stroke among non-teaching staff of the Nnamdi Azikiwe University, Nnewi Campus, Anambra State, Nigeria

Background

The prevalence of stroke is increasing in Nigeria due to a lack of awareness of their predisposing factors. There is therefore a need for good knowledge and awareness of stroke risk factors in the general populations. Thus, this study assessed the level of awareness of stroke risk factors among non-teaching staff in Nnamdi Azikiwe University, Nnewi Campus, Nigeria.

Results

Most of the participants were female, 89 (69%), and had a post-graduate degree, 84 (65.1%). A total of 129 participants participated in this survey, and 91 (70.5%) were familiar with the term “stroke.” The commonest risk factors were high blood pressure (86%), stress (74.4%), and lack of exercise (63.6%). The study showed that the awareness of stroke risk factors among the participants was poor (40.3%).

Conclusion

Stroke awareness was poor among the participants with the highest risk of stroke despite their high literacy level. Female participants, with a postgraduate level qualification and working as senior non-teaching staff, had a better awareness of stroke risk factors than their male colleagues. This shows a need to increase stroke awareness campaigns in the community.

Genetic and Genomic Epidemiology of Stroke in People of African Ancestry

Stroke is one of the leading causes of disability and death worldwide and places a significant burden on healthcare systems. There are significant racial/ethnic differences in the incidence, subtype, and prognosis of stroke, between people of European and African ancestry, of which only about 50% can be explained by traditional stroke risk facts. However, only a small number of genetic studies include individuals of African descent, leaving many gaps in our understanding of stroke genetics among this population. This review article highlights the need for and significance of including African-ancestry individuals in stroke genetic studies and points to the efforts that have been made towards this direction. Additionally, we discuss the caveats, opportunities, and next steps in African stroke genetics-a field still in its infancy but with great potential for expanding our understanding of stroke biology and for developing new therapeutic strategies.

The significant places of African American adults and their perceived influence on cardiovascular disease risk behaviors

BACKGROUND

AA living in rural areas of the southeastern U.S. experience a disproportionate burden of cardiovascular disease (CVD) morbidity and mortality. Neighborhood environmental factors contribute to this disparity and may decrease the effectiveness of lifestyle interventions aimed at preventing CVD. Furthermore, the influence of neighborhood factors on AA CVD risk behaviors (i.e. physical activity) may be obscured by the use of researcher-defined neighborhoods and researcher-defined healthy and unhealthy places. The objective of this study was to elucidate the effects of neighborhood environments on AA CVD risk behaviors among AA adults who recently completed a lifestyle intervention. We specifically sought to identify AA adults' self-perceived places of significance and their perceptions of how these places impact CVD risk behaviors including diet, physical activity and smoking.

METHODS

We conducted semi-structured interviews with AA adults (N = 26) living in two rural North Carolina counties (Edgecombe and Nash, North Carolina, USA). Participants were recruited from a community-based behavioral CVD risk reduction intervention. All had at least one risk factor for CVD. Participants identified significant places including where they spent the most time, meaningful places, and healthy and unhealthy places on local maps. Using these maps as a reference, participants described the impact of each location on their CVD risk behaviors. Data were transcribed verbatim and coded using NVivo 12.

RESULTS

The average age of participants was 63 (SD = 10) and 92% were female. Places participants defined as meaningful and places where they spent the most time included churches and relatives' homes. Healthy places included gyms and parks. Unhealthy places included fast food restaurants and relatives' homes where unhealthy food was served. Place influenced CVD risk behaviors in multiple ways including through degree of perceived control over the environment, emotional attachment and loneliness, caretaking responsibilities, social pressures and social support.

CONCLUSIONS

As we seek to improve cardiovascular interventions for rural AA in the American South, it will be important to further assess the effect of significant places beyond place of residence. Strategies which leverage or modify behavioral influences within person-defined significant places may improve the reach and effectiveness of behavioral lifestyle interventions.

Peripheral Blood Cytopenia and Risk of Cardiovascular Disease and Mortality

Background

Individual blood cell count abnormalities have been associated with cardiovascular disease and increased mortality. In this study, we defined a “cytopenia phenotype,” reflecting bone marrow hypoproliferation, to determine if peripheral blood cytopenia is associated with increased cardiovascular disease and mortality risk.

Methods and Results

Study participants were derived from a biracial observational cohort study, REGARDS (Reasons for Geographic and Racial Differences in Stroke), that enrolled 30 239 Black and White participants aged ≥45 years between 2003 and 2007. Median follow up was ≈9 years. The current study included 19 864 participants from REGARDS study (37.9% men, 40% Black participants) who have complete blood count available at study enrollment. We defined a cytopenia phenotype based on age‐, sex‐, and race‐adjusted lowest fifth percentile of blood counts. Multivariable Cox proportional hazards models estimated the hazard ratios (HR) and 95% CI of cytopenia for mortality and incident cardiovascular disease in adjusted models. Mean age of the study participants was 64 years (SD:9.7). The prevalence of cytopenia was 1.9% (n=378). Cytopenia was associated with increased risk of all‐cause mortality (HR, 1.73; 95% CI, 1.34–2.22) and cardiovascular disease mortality (HR, 1.56; 95% CI, 1.11–2.29). Cytopenia was associated with stroke risk in Black but not White participants (HR, 1.96 versus 0.86; P‐interaction for race=0.08) and was not associated with coronary heart disease risk.

Conclusions

We defined a cytopenia phenotype with clinical implications for mortality and stroke risk in a large biracial and geographically diverse population. Whether generated through somatic mutations or decreased organ function, cytopenia was associated with mortality risk and was a race‐specific risk factor for stroke.

Incidence of Stroke in Immigrants to Canada: A Province-wide Retrospective Analysis

BACKGROUND AND OBJECTIVES

To evaluate the association between immigration status and stroke incidence.

METHODS

We conducted a retrospective cohort study of 8 million adults (15% immigrants) residing in Ontario, Canada, on January 1, 2003, with no history of stroke or TIA. Participants were followed up until March 31, 2018, to identify incident stroke or TIA, defined as hospitalization or emergency room visit. We calculated adjusted hazard ratios (HRs) of stroke or TIA in immigrants compared to long-term residents using cause-specific hazard models, adjusting for demographics and comorbid conditions. We evaluated whether the association varied by age, stroke type, or country of origin of immigrants.

RESULTS

During 109 million person-years of follow-up, we observed 235,336 incident stroke or TIA events. Compared to long-term residents, immigrants had a lower rate of stroke or TIA (10.9 vs 23.4 per 10,000 person-years, HR 0.67, 95% confidence interval [CI] 0.66-0.68). This was true across all age groups and stroke types, with an HR in immigrants vs long-term residents for ischemic stroke of 0.71 (95% CI 0.69-0.72), for intracerebral hemorrhage of 0.89 (95% CI 0.85-0.93), for subarachnoid hemorrhage of 0.85 (95% CI 0.81-0.91), and for TIA of 0.53 (95% CI 0.51-0.54). The magnitude of the reduction in stroke risk associated with immigration status was less pronounced in immigrants from the Caribbean (HR 0.95, 95% CI 0.91-1.00), Latin America (HR 0.85, 95% CI 0.82-0.91), and Africa (HR 0.80, 95% CI 0.74-0.85) than in those from other world regions.

DISCUSSION

Immigrants have a lower rate of stroke or TIA than long-term residents with variation by age, stroke type, and country of origin. This knowledge may be useful for developing targeted primary stroke prevention strategies.