P23 ‘Positive and negative social support and HPA-axis hyperactivity: evidence from glucocorticoids in human hair’

Abstract

Background While positive social support is associated with lower prevalence of disease and better treatment outcomes, negative social relationships can instead have unfavourable consequences for several physical and mental health conditions. However, the specific mechanisms by which this nexus might operate remain poorly understood. Hypothalamic–pituitary–adrenal (HPA) axis hyperactivity owing to psychosocial stress has been proposed as a potential pathway underlying the link between social support and health. Hair glucocorticoids such as cortisol and cortisone are emerging as promising biomarkers of long-term retrospective HPA activation. Therefore, the aim of this investigation was to examine the effects of positive and negative experiences of social support within key relationships (i.e. spouse/partner, children, other family members, and friends) on cortisol and cortisone. Methods These associations were tested in a sample of 2520 older adults (mean age 68.1) from the English Longitudinal Study of Ageing (ELSA). Hair samples were collected in wave 6 (2012/13). To understand the impact of cumulative exposure to poor social support, the analysis used self-reported data from waves 4 (2008/09) and 6. Both aggregated and source-specific effects of social support were tested. Covariates included demographic characteristics, socioeconomic position, health behaviours, and hair characteristics. The analytical strategy was based on multiple linear regression, and missing data were estimated by multiple imputation. Results In cross sectional analyses, participants who reported lower positive or greater negative social support across all sources had higher levels of cortisol, as well as an elevated cortisol-to-cortisone ratio. Amongst the different components of social support, children exhibited the largest effects on both hormones. In longitudinal analyses, cortisol and the ratio were positively associated with the aggregated scores for cumulative exposure to poor social support, evaluated in retrospect over four years. Discussion Experiences of low positive and high negative social support, particularly from children, were both related to higher hair glucocorticoid levels. Hence, poorer quality of social relationships in later life may lead to higher psychosocial stress. This in turn could result in HPA-axis hyperactivity and increase the individual’s susceptibility to poor health. Health and social care interventions should therefore highlight the importance of improving the quality of social relationships, rather than merely enhancing social interactions, in order to reduce stress and ameliorate health.