Perceived Discrimination and Trajectories of C-Reactive Protein: The Jackson Heart Study

Abstract

Introduction: Perceiving discriminatory treatment may contribute to systemic inflammation, a risk factor of cardiovascular pathophysiology. This study evaluated the association of self-reported discrimination with changes in high-sensitivity C-reactive protein and the mediating role of adiposity.

Methods: The sample included 5,145 African-Americans, aged 21-92 years, in the Jackson Heart Study. Everyday, lifetime, and burden from perceived discrimination comprised primary predictors in 3 sets of multivariable linear regression models of baseline (2000-2004) discrimination and natural logarithm of high-sensitivity C-reactive protein. Multivariable linear mixed models assessed mean changes in natural logarithm of high-sensitivity C-reactive protein over the study period (2000-2013). Mediation was quantified by percentage changes in estimates adjusted for BMI, waist circumference, and waist-to-height ratio. Multiple imputation addressed missingness in baseline covariates and in high-sensitivity C-reactive protein taken at all 3 study examinations. Analyses were conducted in 2018.

Results: In cross-sectional analyses, male participants in the middle and highest tertiles of lifetime discrimination had natural logarithm of high-sensitivity C-reactive protein levels that were 0.13 (95% CI= -0.24, -0.01) and 0.15 (95% CI= -0.27, -0.02) natural logarithm(mg/dL) lower than those in the lowest tertile. In longitudinal analyses, all participants reporting more frequent everyday discrimination had a 0.07 natural logarithm(mg/dL) greater increase in natural logarithm of high-sensitivity C-reactive protein per examination than those reporting none (95% CI=0.01, 0.12). A similar trend emerged for lifetime discrimination and changes in natural logarithm of high-sensitivity C-reactive protein (adjusted mean increase per visit: 0.04 natural logarithm[mg/dL], 95% CI=0.01, 0.08). Adiposity did not mediate the longitudinal associations.

Conclusions: Everyday and lifetime discrimination were associated with significant high-sensitivity C-reactive protein increases over 13 years. The physiologic response to discrimination may lead to systemic inflammation.

Figure 1.

Predicted ln(hs-CRP), by frequency of everyday discrimination (fully adjusted model). JHS, Jackson Heart Study; ln(hs-CRP), natural logarithm of high–sensitivity C-reactive protein.