Social Determinants of Health in Early to Mid-Adulthood and Risk of Early-Onset Stroke

BACKGROUND: Despite increasing incidence of stroke among younger adults, the associations of social determinants of health (SDOH) and stroke among younger adults are not well known. This study investigates the associations between SDOH from early adulthood and stroke in a prospective longitudinal cohort. METHODS: We studied participants enrolled in the CARDIA study (Coronary Artery Risk Development in Young Adults). Participants aged 18 to 30 years were enrolled in 1985 and followed through 2022. We investigated longitudinal, time-varying measures of SDOH classified into 5 distinct domains: economic (6 measures), education (1 measure), healthcare (4 measures), neighborhood (2 measures), and social/community (5 measures). The outcome was incident stroke or transient ischemic attack. We evaluated associations between individual SDOH and stroke using unadjusted Cox models. We then evaluated whether a greater cumulative number of adverse SDOH domains (each represented by 1 exposure selected by empirical techniques) was associated with stroke risk after adjustment for demographics. RESULTS: Among the 5114 participants (54.5% were female; baseline age, 25 years; and median follow-up, 37.9 years), 146 individuals experienced stroke or transient ischemic attack, all of which occurred <65 years. Household income (hazard ratio [HR], 1.24 per $10 000 lower [95% CI, 1.11–1.39]), education (HR, 0.93 per greater year [95% CI, 0.87–0.99]), neighborhood deprivation (HR, 1.21 [95% CI, 1.02–1.43]), and lacking health insurance (HR, 1.49 [95% CI, 1.05–2.11]) were associated with stroke risk. Those experiencing 2 adverse SDOH domains (HR, 1.65 [95% CI, 0.91–2.97]) or ≥ 3 adverse domains (HR, 2.00 [95% CI, 1.09–3.66]) had progressively higher stroke risk ( P trend =0.005). In interaction analyses, the association between income and stroke appeared stronger in Black participants ( P interaction =0.02) and women ( P interaction =0.02). CONCLUSIONS: In this young cohort followed through midlife, SDOH spanning several domains were associated with stroke risk. We also observed a dose-dependent response with the number of adverse SDOH domains experienced. Our results suggest that SDOH experienced throughout adulthood are relevant to future stroke risk.