Race and Regional Differences in Cerebral Microbleeds in Individuals with Incident Stroke or Transient Ischemic Attack: The REGARDS Study.

Background

Cerebral microbleeds (CMBs) are associated with risk of stroke, cognitive impairment, and dementia. The influence of race and/or region of residence on CMB is underexplored.

Methods

REasons for Geographic and Racial Differences in Stroke (REGARDS) study participants with incident stroke/TIA and available MRI were included. CMBs were classified as any, non-lobar, lobar or mixed CMB. Counts were recorded. Multivariable logistic regression assessed associations between race and/or region of residence with CMB presence. Multivariable negative binomial regression related these factors to CMB counts. Models adjusted for age, sex, vascular risk factors.

Results

Among 808 participants (317 Black participants, 412 in stroke belt), Black participants had higher odds of any CMB, odds ratio (OR) = 1.72; 95% confidence interval (CI) 1.22, 2.43). Stroke belt residents had lower odds of any (OR = 0.51, 95% CI 0.37, 0.72), non-lobar (OR = 0.46; 95% CI 0.24, 0.85), lobar (OR = 0.60; 95% CI 0.38, 0.93) CMBs and lower odds of CMB counts (rate ratio [RR] = 0.66, 95% CI 0.43, 0.99). Black participants residing in the stroke belt had higher odds of any (OR = 1.88; 95% CI 1.11, 3.20) and mixed (OR = 2.99; 95% CI 1.19, 7.74) CMBs.

Conclusions

Black participants had higher risk for CMBs. Higher risk in Black participants may suggest increased subclinical vascular brain injury.