Stroke Belt birth state and late-life cognition in the Study of Healthy Aging in African Americans (STAR)

Purpose: We examined the association of Stroke Belt birth state with late-life cognition in The Study of Healthy Aging in African Americans (STAR). Methods: STAR enrolled 764 Black Americans ages 50+ who were long-term Kaiser Permanente Northern California members. Participants completed Multiphasic Health Check-ups (MHC; 1964–1985) where early-life overweight/obesity, hypertension, diabetes, and hyperlipidemia were measured. At STAR (2018), birth state, self-reported early-life socioeconomic status (SES), and executive function, verbal episodic memory, and semantic memory scores were collected. We used linear regression to examine the association between Stroke Belt birth and late-life cognition adjusting for birth year, gender, and parental education. We evaluated early-life SES and cardiovascular risk factors (CVRF) as potential mechanisms. Results: Twenty-seven percent of participants were born in the Stroke Belt with a mean age of 69 (standard deviation = 9) at STAR. Stroke Belt birth was associated with worse late-life executive function (β [95% confidence interval]: −0.18 [−0.33, −0.02]) and semantic memory (−0.37 [−0.53, −0.21]), but not verbal episodic memory (−0.04 [−0.20, 0.12]). Adjustment for SES and CVRF attenuated associations of Stroke Belt birth with cognition (executive function [−0.05 {−0.25, 0.14}]; semantic memory [−0.28 {−0.49, −0.07}]). Conclusions: Black Americans born in the Stroke Belt had worse late-life cognition than those born elsewhere, underscoring the importance of early-life exposures on brain health.