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

Abstract Background Pathways explaining racial/ethnic disparities in dementia risk are under‐evaluated. Method We 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). Result After ≤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. Conclusion Pending future interventions, lifestyle factors including diet, smoking, physical activity and sleep are crucial for reducing racial and socio‐economic disparities in dementia.