Peer Support as Moderator of Association Between Socioeconomic Status and Low-Grade Inflammation in Adolescents

Objective: Individuals who grow up in low-socioeconomic status (SES) families are at an increased risk of health problems across the lifespan. Although supportive social relationships are postulated to be a protective factor for the health of these individuals, the role of friend support in adolescence is not well understood. Given that low-grade inflammation is one key biological mechanism proposed to explain links between family SES and health outcomes, we examined whether adolescents' friend support buffers the association between family SES and low-grade inflammation among adolescents. Method: 277 dyads of adolescents (63.5% female; 39.4% White, 38.3% Black, and 32.1% Hispanic; M-age = 13.92 years) and one of their parents participated in this longitudinal study (two waves approximately 2 years apart). Parents reported family objective SES (i.e., income, savings, and education) and family subjective SES (i.e., subjective social status). Adolescents reported perceived friend support. Fasting antecubital blood was drawn from adolescents at both visits. Low-grade inflammatory activity was represented by a composite of inflammatory biomarkers and numbers of classical monocytes. Results: Adolescents' friend support moderated the associations of family subjective SES with both the inflammation composite and classical monocyte counts across cross-sectional, longitudinal, and prospective change (only significant for the inflammation composite) analyses. Specifically, lower family subjective SES was associated with higher levels of low-grade inflammation only among adolescents lower, but not higher, in friend support. No moderation was observed for objective SES. Conclusion: Supportive peer relationships buffer the link between family subjective, but not objective, SES and low-grade inflammation in adolescence.