Aging
Social vulnerability and incidence of all-cause dementia and Alzheimer’s disease in the United States Laura Arboleda Merino* Laura Arboleda Merino Arboleda Merino Arboleda Merino Arboleda Merino Arboleda Merino Arboleda Merino Arboleda Merino Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA.
Introduction: Dementia is a growing global public health concern. Lifestyle and environmental risks for dementia operate within wider social and structural contexts, where increased social vulnerability can amplify obstacles to prevention, early detection, and care. We evaluated the association between social vulnerability and the incidence of Alzheimer’s disease (AD) and all-cause dementia among U.S. adults.
Methods: We linked data from the National Health and Nutrition Examination Survey (NHANES, 1999-2016) with Medicare claims to identify incident AD and all-cause dementia cases through 2018. A modified Social Vulnerability Index (SVI) was constructed by summing seven individual-level indicators: income, education, health insurance, race/ethnicity, employment, housing tenure, and food security, yielding a score from 0 (least) to 7 (most vulnerable). High SVI was defined as quartile 4, while low SVI as quartiles 1–3. Adjusted hazard ratios were estimated using survey-weighted Cox proportional hazards models with age as the time scale.
Results: Participants (N=9,190) had a mean baseline age of 64.8 years and an average SVI of 1.53. Over a mean follow-up of 9.06 years for AD and 8.86 years for all-cause dementia, 641 developed AD and 1,393 individuals developed dementia. Higher social vulnerability was consistently associated with elevated dementia risk. Compared with individuals in the low-SVI group, the high-SVI group had a 32% higher risk of AD (HR: 1.32, 95% CI: 1.08-1.62) and a 66% higher risk of all-cause dementia (HR: 1.66, 95% CI: 1.45-1.89). Modeled continuously, a one-unit increase in SVI corresponded to an 11% higher risk of AD (HR: 1.11, 95% CI: 1.05-1.17) and a 19% higher risk of all-cause dementia (HR: 1.19, 95% CI: 1.15-1.23).
Conclusion: Higher social vulnerability was strongly associated with increased risk of incident dementia. Addressing social and structural determinants of health may be critical to reducing this growing public-health burden.