Multiple forms of discrimination and inflammation in Black Americans: Are there differences by sex?

Rationale: Discrimination is a risk factor and potential pathway through which social determinants such as race and sex contribute to chronic inflammation in Black Americans in middle and later adulthood. Questions remain regarding which forms of discrimination are most salient for inflammatory dysregulation, and whether there are sex-based differences in these pathways.

Objective: This exploratory study investigates sex differences in the relationships between four forms of discrimination and inflammatory dysregulation among middle aged and older Black Americans.

Methods: Using cross-sectionally linked data from participants in the Midlife in the United States (MIDUS II) Survey (2004-2006) and Biomarker Project (2004-2009) (N = 225, ages 37-84, 67% female), this study conducted a series of multivariable regression analyses. Inflammatory burden was measured using a composite indicator comprised of five biomarkers: C-reactive protein (CRP), interleukin-6 (IL-6), fibrinogen, E-selectin, and intercellular adhesion molecule (ICAM). Discrimination measures were lifetime, daily, and chronic job discrimination and perceived inequality at work.

Results: Black men generally reported higher levels of discrimination than Black women (3 out of 4 forms), though only sex differences in job discrimination achieved statistical significance (p < .001). In contrast, Black women exhibited more overall inflammatory burden than Black men (2.09 vs. 1.66, p = .024), particularly elevated levels of fibrinogen (p = .003). Lifetime discrimination and inequality at work were associated with higher levels of inflammatory burden, after adjusting for demographic and health factors (p = .057 and p = .029, respectively). The discrimination-inflammation relationships further varied by sex, such that more lifetime and job discrimination predicted greater inflammatory burden in Black women, but not in Black men.

Conclusion: These findings highlight the potentially detrimental impact of discrimination and emphasize the importance of sex-specific research on biological mechanisms of health and health disparities in Black Americans.