Associations of epigenetic aging with self-rated health, access to care, and healthcare utilization in a representative sample of United States adults.

Background: Health status is closely linked to both healthcare access and utilization. While previous research has identified associations between health status and DNA methylation-based biomarkers of aging (epigenetic aging), studies exploring these relationships in the context of healthcare access and utilization remain limited. To address this gap, we analyzed cross-sectional associations in a representative sample of 2,343 U.S. adults from the 1999-2000 and 2001-2002 cycles of the National Health and Nutrition Examination Survey (NHANES). Our study examined the relationships of self-rated health status, healthcare access, and healthcare utilization with seven epigenetic aging biomarkers: HannumAge, HorvathAge, SkinBloodAge, PhenoAge, GrimAge2, DNAm Telomere Length (DNAmTL), and DunedinPoAm.

Results: After adjusting for chronological age, demographics, lifestyle factors, and health insurance, participants with good-excellent self-rated health had a 1.58-year lower PhenoAge (95% CI - 2.54, - 0.62 P = 0.006) and a 1.16-year lower GrimAge2 (95% CI - 1.80, - 0.53, P = 0.004) than participants with poor-fair health. Participants who reported having a routine place where they received healthcare had a lower GrimAge2 (β = - 1.44-years, 95% CI - 2.66, - 0.22, P = 0.03) than participants without a routine healthcare location. Participants with ≥ 10 healthcare visits in the prior year had a shorter DNAmTL (β = - 0.05-kb, 95% CI - 0.09, - 0.01, P = 0.02) than participants with < 10 visits. After including additional adjustments for estimated leukocyte proportions, participants who were hospitalized overnight in the prior year had a shorter DNAmTL (β = - 0.05-kb, 95% CI - 0.08, - 0.01, P = 0.02) than non-hospitalized individuals.

Conclusions: Our findings reinforce previous reports linking better health status to lower epigenetic aging and provide new evidence of associations of epigenetic aging with measures of healthcare access and utilization. If validated, these findings suggest that epigenetic aging biomarkers may be useful in studying disease processes and assessing health outcomes related to access and utilization.