Accelerated molecular aging in socioeconomically disadvantaged neighborhoods: A racial/ethnic comparison

In the US, racial/ethnic health disparities are undeniable. These disparities partially stem from residing in low socioeconomic neighborhoods, a circumstance to which racial/ethnic minorities are disproportionately exposed. Associations between socioeconomic status (SES) and health may have some underlying molecular mechanisms reflected in the epigenome. Yet, a growing body of research suggests that neighborhood characteristics are not experienced the same way for individuals from differing racial/ethnic backgrounds. The present study evaluated associations between area-based SES and epigenetic age as assessed by the Horvath, Hannum, PhenoAge, and GrimAge epigenetic clocks in a national sample of older non-Hispanic White, non-Hispanic Black, and Hispanic participants. The present study used epigenetic age data from 3790 participants in the 2016 wave of the Health and Retirement Study and census tract SES data from the 2012-2016 American Community Survey. Four epigenetic clocks were regressed on area-based SES, adjusting for age, sex, and educational attainment. Although area-based SES was not significantly associated with Horvath or Hannum clocks, living in lower SES census tracts was associated with older PhenoAge and GrimAge. After considering smoking status, however, only the association with GrimAge remained. Investigating interactions with race/ethnicity suggested that area-based SES was more strongly associated with accelerated Hannum, PhenoAge, and GrimAge among non-Hispanic White participants than for other racial/ethnic groups. These racial/ethnic differences were completely reduced, however, in models that included smoking status. The present results illuminated racially/ethnically distinct patterns of biological (epigenetic aging) and behavioral (smoking) risk for poor health, and suggested that ameliorating low area-based SES may be beneficial for racially/ethnically diverse populations.