The association between Body Roundness Index and epigenetic aging: insights from the Health and Retirement Study

<title>Abstract</title> <p>Background The Body Roundness Index (BRI) has been proved to be associated with several metabolic and age-related disorders, with epigenetic pathways potentially underlying these connections. We analyzed data from the Health and Retirement Database to investigate whether higher BRI is linked to epigenetic aging Methods Using cross-sectional data from the Health and Retirement Study, we investigated the relationship between BRI and epigenetic aging. Epigenetic age acceleration (EAA) was calculated from five established DNA methylation clocks as the residual values from regressing epigenetic age on chronological age. The continuous associations were evaluated using linear regression and restricted cubic spline models. Subgroup analyses were conducted to assess consistency across different population strata. Logistic regression was applied to examine the link between BRI and accelerated aging (EAA > 0). Results A total of 1,801 participants aged ≥ 50 years were included in this cross-sectional analysis, with a mean BRI of 6.01. Linear regression analyses demonstrated that higher BRI was significantly associated with increased epigenetic age acceleration based on GrimAge, PhenoAge, and DunedinPoAm. These findings remained consistent in restricted cubic spline analyses and across subgroup analyses. Logistic regression models further supported these associations, showing that the odds of accelerated aging rose by 19.7% for GrimAge, 31.8% for PhenoAge, and 38.8% for DunedinPoAm for each 2.27-unit increase in BRI. Conclusion BRI was strongly associated with epigenetic age acceleration measured by GrimAge, PhenoAge, and DunedinPoAm, suggesting that increased visceral adiposity may contribute to epigenetic alterations.</p>