Is the relationship between depression and c reactive protein level moderated by social support in elderly?-Korean social life, health, and aging project (KSHAP)

Objective To investigate the buffering effects of social support as an effects modifier in the association between depression and inflammation in the elderly. Methods We analyzed the Korean Social Life, Health, and Aging Project (KSHAP) for questionnaire, clinical, and laboratory data of 530 older adults living in a rural community. Multivariate regression models were used to investigate the association between depressive symptoms and C-reactive protein level (CRP), a marker of inflammation, at varying levels of social support. Results Social support affected the association between depressive symptoms and CRP level in both sexes. However, the direction of effects modification was different for men and women. In men, a higher CRP level was significantly associated with depressive symptoms only among those with lower support from a spouse or family members. By contrast, in women, the association was significant only among subgroups with higher spousal or family support. Social support from neighbors or friends did not affect the depression-inflammation relationship in men but modestly affected the relationship in women. Conclusion Our findings suggest that social support may have a buffering effect in the relationship between depression and inflammation in elderly Koreans. But the influence of social support may run in different directions for men and women.