Sexual Minority Adults Exhibit Greater Inflammation than Heterosexual Adults in the Context of Depressive Symptoms and Anxiety: Pathways to Health Disparities

Background: Sexual minority individuals, including lesbian, gay, bisexual, and other non-heterosexual (LGB+) adults have significantly greater risk for mental and physical health conditions, disparities linked with minority stress exposure. Methods: Utilizing a Biopsychosocial Minority Stress Framework, this study examined depressive symptoms, anxiety, and inflammatory markers [interleukin(IL)-6 and C-reactive protein (CRP)] in a diverse sample of 572 adults (321 heterosexual; 251 LGB+). Results: LGB+ adults reported greater anxiety and depressive symptoms (ps < 0.01). This effect was partially mediated by greater exposure to adverse childhood experiences (ACES) among LGB+ respondents. Compared to heterosexual adults, controlling for key potential confounds, LGB+ adults exhibited greater elevations in both IL-6 (BSM = 0.025, SE = 0.011 vs BHETERO = -0.0068, SE = 0.01; interaction p = 0.031) and CRP (BSM = 0.036, SE = 0.013 vs. BHETERO = -0.0090, SE = 0.013; interaction p = 0.012) in relation to depressive symptoms. LGB+ adults also showed greater increases in CRP in the context of anxiety (BSM = 0.043, SE = 0.017 vs BHETERO = -0.011, SE = 0.015; interaction p = 0.017). These effects were not accounted for by differences in body mass index (BMI) or tobacco use. Conclusions: LGB+ adults may experience greater inflammatory burden due to both 1) greater prevalence of anxiety and depression, and 2) sensitization to negative inflammatory sequalae in the context of anxiety and depression. Greater ACES contributed to the greater prevalence of anxiety and depressive symptoms among LGB+ as compared to heterosexual participants. Ultimately, differential prevalence of, and physiological responses, to anxiety and depressive symptoms may contribute to physical and mental health disparities among sexual minority adults.