Epigenetic correlates of Stressful Life Events

Adaptation to the environment is a fundamental part of life, but excessive exposure to stress can lead to maladaptive alterations in a range of bodily systems, with implications for downstream health outcomes. The biological embedding of stress may be partly mediated by DNA methylation, an epigenetic modification which makes genes more or less accessible for use by the body. We use two subsamples of Understanding Society (UKHLS) to measure the epigenetic correlates of objectively-measured stressful life events (SLEs) in a number of ways: by performing linear regressions of methylation-based estimates of both ageing “clocks” and white blood cell (WBC) proportions, and by performing epigenome-wide association analyses (EWAS) to examine methylation at individual sites (CpGs) across the genome. We capitalise on the rich social data in UKHLS to sequentially adjust for a range of sociodemographic, health-related and psychosocial factors, including moderation by social support and job satisfaction. To capture the subjective experience of stress, analyses are repeated using an interaction between SLEs and psychological distress. We find that some ageing clocks and WBC estimates are associated with SLEs, but no individual CpGs reach experiment-wide significance. Replication is scarce across the two subsamples, which may be due to differences in both representativeness and covariate structure.