Social connectedness and hair cortisol in community-dwelling older adults.

Purpose: Hair cortisol is emerging as a reliable biomarker for measuring retrospective stress hormone levels. Given that social connectedness can buffer psychobiological stress reactivity, increasing attention is being paid to the specific types of social networks associated with the stress response. This study investigated the role played by two components of social life, emotional closeness and network size, to probe which aspects of social networks were related to stress measures. Methods: The scalp hair cortisol level was used to assess the cumulative cortisol production in 179 community-dwelling older adults, in the Korean Social Life, Health, and Aging Project (KSHAP). Multivariate regression approach was used to examine the link between the stress measures (cortisol and perceived stress scale) and social relationships (social network size and emotional closeness). Results: Emotional closeness (the average level of what one feels about one's relationship) was significantly associated with decreased levels of hair cortisol, whereas no such relationship was found with the network size. Conclusions: The current findings underscore the role of emotional support on reducing cumulative cortisol, thus providing potential resilience mechanisms for the psychobiological stress response.