An epigenetic clock for chronological age estimation in East Asian populations.

Population aging is increasing the burden of age-related disease, highlighting the need for accurate molecular tools to estimate aging. DNA methylation, a heritable epigenetic mark linked to development and age-related disease, can capture biological aging and predict chronological age; however, most existing epigenetic clocks were developed primarily in non-East Asian populations and may show reduced calibration across ancestries. We analyzed methylation profiles from East Asian cohorts from Taiwan, Japan, and China to develop an East Asian-specific epigenetic clock, termed the EAS Clock. After quality control and probe filtering, a parsimonious model based on 38 CpG sites was constructed using stepwise multivariate regression with forward selection and Bayesian Information Criterion. The EAS Clock showed significant correlations between predicted and chronological age in both training and independent testing datasets, with residuals centered near zero. Functional enrichment analyses indicated that genes associated with the selected CpGs were involved in neurobiological, musculoskeletal, immune-inflammatory, and lipid-metabolic pathways. These findings support the EAS Clock as a compact methylation-based estimator of chronological age tailored to East Asian populations.