Abstract Body: Introduction: Cerebral microbleeds (CMB) are subclinical markers of cerebral small vessel disease (CSVD) denoting increased risk of stroke, cognitive impairment and dementia. The influence of race and region of residence on the prevalence, burden and brain location of CMB is understudied.
Aim: Determine the impact of geographic and racial differences in prevalence and burden of CMB among participants in the REGARDS cohort study.
Methods: Among the 30,239 participants followed since 2003-7 in the REGARDS study, CMB ratings was performed on MRI from those with stroke or TIA. CMBs were classified by brain topography as any CMB, non-lobar, and lobar CMB, and CMB counts were recorded. Multivariable logistic regression was used to assess the associations of race and region of residence (stroke belt vs. non-stroke belt) with CMB. We used negative binomial regression to relate race and region of residence with CMB count. Models were adjusted for age, sex and vascular risk factors such as hypertension, diabetes, smoking, total cholesterol.
Results: Among participants with stroke or TIA, 808 had the correct sequence and thus CMB ratings. CMB was more prevalent in Black participants in both the stroke belt and non-stroke belt. Black participants with CMB were younger, and had higher proportion of hypertension compared to White participants with CMB. Black participants had higher odds of any CMB (OR 1.72; 95% CI 1.22, 2.43), non-lobar CMB (OR 1.59; 95 %1.02, 2.47), and lobar CMB (OR 1.66; 95% CI 1.13, 2.42) compared to White participants. Participants from the stroke belt had lower odds of any (OR 0.51; 0.37, 0.72), non-lobar (OR 0.53; 95% CI 0.34, 0.82) and lobar (OR 0.58; 0.40, 0.84) CMBs, as well as a lower odd of having zero CMB counts (RR 0.66, 95% CI 0.43 – 0.99) compared to non-stroke belt resident. Black persons residing in the stroke belt (RR 1.85, 95% CI 0.91 – 3.79) and non-stroke belt (RR 1.27, 95% CI 0.75 – 2.12) showed a trend towards having greater number of CMBs compared to White participants in both regions.
Conclusion: Evidence of CSVD was more prevalent in general among Black participants. Additionally, Black participants with CMB were younger and more likely to have hypertension. Intervention to reduce brain health disparity will need to target hypertension as a risk factor.