Research Paper|Volume 15, Issue 18|pp 9310—9340

Pathways explaining racial/ethnic and socio-economic disparities in dementia incidence: the UK Biobank study

May A. Beydoun¹, Hind A. Beydoun², Marie T. Fanelli-Kuczmarski¹, Jordan Weiss³, Michael F. Georgescu¹, Osorio Meirelles¹, Donald M. Lyall⁴, Michele K. Evans¹, Alan B. Zonderman¹

¹Laboratory of Epidemiology and Population Sciences, National Institute on Aging, NIA/NIH/IRP, Baltimore, MD 21224, USA
²Department of Research Programs, Fort Belvoir Community Hospital, Fort Belvoir, VA 22060, USA
³Stanford Center on Longevity, Stanford University, Stanford, CA 94305, USA
⁴School of Health and Wellbeing, University of Glasgow, Glasgow, Scottland, UK

Received: May 8, 2023Accepted: August 21, 2023Published: September 25, 2023

https://doi.org/10.18632/aging.205058

Copyright: © 2023 Beydoun et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract

Background: Pathways explaining racial/ethnic disparities in dementia risk are under-evaluated.

Methods: We examine those disparities and their related pathways among UK Biobank study respondents (50–74 y, N = 323,483; 3.6% non-White minorities) using a series of Cox proportional hazards and generalized structural equations models (GSEM).

Results: After ≤15 years, 5,491 all-cause dementia cases were diagnosed. Racial minority status (RACE_ETHN, Non-White vs. White) 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 (LE8_LIFESTYLE), 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 racial minorities included ‘RACE_ETHN(−) → SES(−) → DEMENTIA’, ‘RACE_ETHN(−) → SES(−) → Poor cognitive performance, COGN(+) → DEMENTIA’ and ‘RACE_ETHN(−) → SES(+) → LE8_LIFESTYLE(−) → DEMENTIA’.

Conclusions: Pending future interventions, lifestyle factors including diet, smoking, physical activity, and sleep are crucial for reducing racial and socio-economic disparities in dementia.