Longitudinal association of circulating inflammatory biomarkers with epigenetic ageing in the Young Finns Study.

DNA methylation-based epigenetic clocks are reliable measures of biological age and aging rate. Chronic inflammation may contribute to aging and various diseases, but population-based studies on specific inflammatory biomarkers’ impact on epigenetic clocks are limited. The aim of this study was to investigate the associations between 38 circulating inflammatory biomarkers, as well as a combined systemic inflammation variable, and epigenetic clocks in a middle-aged population. The cohort included 1,327 Finnish participants (aged 30–45 years, 50–55% female) from the Young Finns Study. Biomarkers were measured in 2007, and epigenetic clocks were assessed in 2011 and 2018. DunedinPACE and PCGrimAgeDev clocks were calculated using blood methylation data. Multiple linear regression models adjusted for age, sex, BMI, smoking, socioeconomic status, alcohol consumption, and physical activity were used. Results showed 11 biomarkers positively associated with DunedinPACE across both follow-ups. Seven biomarkers were positively associated with PCGrimAgeDev in the 4-year follow-up, but not in the 11-year follow-up. The combined systemic inflammation marker was positively associated with both clocks in both follow-ups. Although previous cross-sectional studies have reported associations between pro-inflammatory cytokines and epigenetic ageing, longitudinal findings remain sparse. Our results extend this literature by showing that several cytokines predict accelerated epigenetic ageing across an 11-year follow-up.