Pathways explaining racial/ethnic and socio‐economic disparities in dementia incidence: The UK Biobank Study

Abstract

AbstractBackgroundPathways explaining racial/ethnic disparities in dementia risk are under‐evaluated.MethodWe examine those disparities and their related pathways among UK biobank study respondents (50‐74y, N = 323,483; 3.6% non‐White minorities) using a series of Cox proportional hazards and generalized structural equations models (GSEM).ResultAfter ≤15 years, 5,491 all‐cause dementia cases were diagnosed. Minority status increased dementia risk by 24% (HR = 1.24, 95% CI: 1.07‐1.45, P = 0.005), an association attenuated by socio‐economic status (SES), (HR = 1.12, 95% CI: 0.96‐1.31). Total race‐dementia effect was mediated through both SES and Life’s essential 8 lifestyle sub‐score (LE8LIFESTYLE), combining diet, smoking, physical activity, and sleep factors. SES was inversely related to dementia risk (HR = 0.69, 95% CI: 0.67, 0.72, P<0.001). Pathways explaining excess dementia risk among minorities included ‘RACE_ETHN(‐)→SES(‐)→◊ DEMENTIA’, ‘RACE_ETHN(‐)→ SES(‐)→ COGN(+)→ DEMENTIA’ and ‘RACE_ETHN(‐)→SES(+)→ LE8LIFESTYLE(‐)→`DEMENTIA’, with SES reflecting higher socio‐economic status, COGN reflecting poorer cognitive performance and LE8LIFESTYLE reflecting better cardiovascular health, specifically lifestyle factors, with higher scores. RACE_ETHN is the Non‐White minority vs. White contrast.ConclusionPending future interventions, lifestyle factors including diet, smoking, physical activity and sleep are crucial for reducing racial and socio‐economic disparities in dementia.