Obesity and accelerated epigenetic aging in a high-risk cohort of children

Background: New insights into mechanisms linking obesity to poor health outcomes suggest a role for cellular aging pathways, casting obesity as a disease of accelerated biological aging. Although obesity has been linked to accelerated epigenetic aging in middle-aged adults, the impact during childhood remains unclear. We tested the association between body mass index (BMI) and accelerated epigenetic aging in a cohort of high-risk children. Participants were children (N=273, aged 8 to 14 years, 82% investigated for maltreatment) recruited to the Child Health Study, an ongoing prospective study of youth investigated for maltreatment and a comparison youth. BMI was measured as a continuous variable. Accelerated epigenetic aging of blood leukocytes was defined as the age-adjusted residuals of several established epigenetic aging clocks (Horvath, Hannum, GrimAge, PhenoAge) along with a newer algorithm, the DunedinPoAm, developed to quantify the pace-of-aging. Hypotheses were tested with generalized linear models. Results: Higher BMI was significantly correlated with older chronological age, maltreatment status, household income, blood cell counts, and three of the accelerated epigenetic aging measures: GrimAge (r=0.29, P<.0001), PhenoAge (r=0.25, P<.0001), and DunedinPoAm (r=0.37, P<.0001). In fully adjusted models, GrimAge (b=.06; P=.007) and DunedinPoAm (b=.0017; P<.0001) remained significantly associated with higher BMI. Maltreatment-status was not independently associated with accelerated epigenetic aging after accounting for other factors. Conclusion: In a high-risk cohort of children, higher BMI predicted epigenetic aging as assessed by two epigenetic aging clocks. These results suggest the association between obesity and accelerated epigenetic aging begins in early life, with implications for future morbidity and mortality risk.