Health behavior mechanisms linking childhood socioeconomic status to Alzheimer's disease and related dementia risk: Exploring gender and racial/ethnic differences

Abstract

Background

Lower childhood socioeconomic status (cSES) has been linked to a higher risk of Alzheimer's disease and related dementia (ADRD). Yet, the mechanisms underlying this association remain unclear.

Objective

This study examined whether poorer health behaviors in adulthood mediate the association between lower cSES and ADRD risk. We further explored whether the mediating effects of health behaviors vary by gender or race/ethnicity.

Methods

Data were drawn from 26,631 participants in the Health and Retirement Study (M_age = 61.18 years). Cox proportional hazard models were used to estimate the association between cSES and ADRD risk, as well as the mediating effects of health behaviors, including smoking, heavy drinking, physical activity, and influenza vaccination.

Results

Lower cSES was associated with a higher risk of ADRD (hazard ratio = 1.06, [1.02, 1.09]). Lower physical activity mediated this association, accounting for 17.1% of the total effect of cSES on ADRD risk. Subgroup analyses revealed that this mediation was consistent across all gender and racial/ethnic groups, except for foreign-born Hispanics. Smoking mediated the association only for men, explaining 4.2% of the total effect.

Conclusions

These findings suggest that lower cSES may be a risk factor for ADRD partially through lower physical activity across most demographic groups. Interventions promoting physical activity in adulthood could help mitigate the adverse effect of low cSES on ADRD risk. Furthermore, smoking prevention programs may be particularly beneficial for men from lower socioeconomic backgrounds.