Perceived social support-giving moderates the association between social relationships and interleukin-6 levels in blood.

Although positive social relationships are assumed to relate to lower levels of chronic systemic inflammation, the empirical evidence on this association is mixed. This study examines whether perceived social support-giving (i.e., the belief that one can be available to give social support to others, henceforward referred to as perceived support-giving) moderates associations between social relationships and inflammation using data from the longitudinal follow-up of the National Survey of Midlife Development in the U.S. (MIDUS II). Middle-aged adults (N = 1054) completed self-report questionnaires on social integration, perceived support-availability from others, positive relations with others, perceived support-giving, socio-demographic information, and health-related information and provided blood samples for measurement of interleukin-6 (IL-6) as a marker of systemic inflammation. The results showed that perceived support-giving moderated the associations between IL-6 and indicators of positive social relationships, including social integration, perceived support-availability, and positive relations with others. Indicators of positive social relationships were associated with lower IL-6 among individuals higher, but not lower, in perceived support-giving. The moderating effects of perceived support-giving held after adjusting for socio-demographic and health-related covariates. Therefore, positive social relationships are associated with lower IL-6 only for individuals who believe they can give more support in those relationships. In addition, preliminary evidence indicated that the moderating effects of perceived support-giving might be further qualified by gender, being significant only in women.