Social Integration, Daily Discrimination, and Biological Markers of Health in Mid- and Later Life: Does Self-Esteem Play an Intermediary Role?

BACKGROUND AND OBJECTIVES: This cross-sectional study examines associations of social integration and daily discrimination with 4 biological markers of inflammation and cardiovascular health and tests whether self-esteem may mediate any of these effects. RESEARCH DESIGN AND METHODS: Data came from 746 participants of the National Survey of Midlife Development in the United States (MIDUS) Refresher (2011–2014) and MIDUS Refresher Biomarker Project (2012–2016). Structural equation modeling estimated direct and indirect associations of social integration and daily discrimination with glycosylated hemoglobin (HbA1c), high-density lipoprotein (HDL), C-reactive protein, and interleukin-6. RESULTS: Social integration and daily discrimination were both significantly associated with self-esteem, which was in turn associated with HbA1c, HDL, and interleukin-6 levels. Social integration was indirectly associated with HbA1c, HDL, and interleukin-6 via self-esteem. Daily discrimination was directly associated with HbA1c, C-reactive protein, and interleukin-6 and was indirectly associated with HDL and interleukin-6 via self-esteem. DISCUSSION AND IMPLICATIONS: Findings identify social correlates of inflammation and cardiovascular risk and suggest that self-esteem may serve as a pathway for effects. Overall, results were somewhat mixed: Daily discrimination was directly associated with both self-esteem and 3 of the 4 biological markers of health; however, although social integration was strongly associated with self-esteem, it was only weakly and indirectly associated with biological health markers. Moreover, the indirect effects of daily discrimination on the biomarker outcomes—while significant—were notably smaller than its direct effects. Implications for theory, practice, and future research are discussed, including the need for further study of self-esteem and physical health across mid- and later life.