The experience of social loss and epigenome-wide DNA methylation

Social loss is associated with mental and physical health problems. Considering known risk and resilience factors, we hypothesized that epigenome-wide DNA methylation (DNAm) would be associated with social loss.

A total of N = 1865 participants aged 50-75 years with epigenome-wide DNAm measurements obtained from whole blood samples were included. Using cross-sectional data, relationship status (married/divorced/widowed) was expected to predict differences in DNAm between married persons and persons who experienced social loss (divorced/widowhood). Additionally, social factors (i.e., the number of close social relationships and household size), the polygenic risk score for depression, a history of depression, and biological sex were considered as moderators. Predicted differences in DNAm were calculated (Δ-beta values).

Without considering moderators, there was only one differentially methylated position (DMP; cg01450896), comparing married and widowed persons (b = 0.098, q = 0.022; Δ-beta = |0.015|). However, there were a variety of DMPs for the comparison between married persons and those who experienced social loss when the moderators were factored in, especially those indicative of social integration and social connectedness. Δ-beta values varied considerably as a function of changes in the moderators.

Changes in DNAm might contribute to the health-related effects of social loss. In line with his, many of the discovered DMPs were associated with health-related traits in previous studies. However, the reported effects were highly dependent on the moderators assessed and specific to divorce and widowhood. The results could provide a first step toward better understanding and treating individuals who experienced social loss.