Low Social Engagement and Risk of Death in Older Adults

ABSTRACT Background Social engagement contributes to healthy aging, yet the mechanisms linking social engagement to mortality risk remain poorly understood. This study investigated the biological, behavioral, and psychological pathways mediating this relationship. Methods We conducted a prospective cohort study using Health and Retirement Study (HRS) data on participants aged 60 and older who completed the Psychosocial and Lifestyle Questionnaires and provided blood samples in 2016. Social engagement was assessed using nine items from the HRS Social Participation questionnaire, with responses categorized as low, moderate, or high. Biological age was calculated using the Klemera–Doubal method and compared to chronological age to identify decelerated aging. We explored mediating pathways between social engagement and 4‐year mortality risk using counterfactual mediation analyses. Results In total, 2268 participants were included. Higher social engagement was associated with lower all‐cause mortality rates over 4 years of follow‐up. The high social engagement group participants had a lower median biological age, healthier behaviors, and lower prevalence of depressive symptoms than those in the low and moderate engagement groups. High social engagement was associated with lower mortality risk than low engagement (a‐HR: 0.58 [95% CI: 0.39, 0.86; p = 0.009]). This effect was partially mediated by regular physical activity (16%) and decelerated biological age (15%). Other factors such as high depressive symptoms, excess alcohol use, and tobacco use showed no significant mediating effects. Conclusions Higher social engagement in older adults is associated with reduced mortality risk possibly due to decreased biological aging and increased physical activity levels.