Racial Differences in Elevated C-Reactive Protein Among US Older Adults.

ABSTRACT

OBJECTIVES: To investigate racial differences in elevated C-reactive protein (CRP) and the potential factors contributing to these differences in US older men and women. DESIGN: Nationally representative cohort study. SETTING: Health and Retirement Study, 2006 to 2014. PARTICIPANTS: Noninstitutionalized non-Hispanic black and white older adults living in the United States (n = 13 517). MEASUREMENTS CRP was categorized as elevated (>3.0 mg/L) and nonelevated (≤3.0 mg/L) as the primary outcome. Measures for demographic background, socioeconomic status, psychosocial factors, health behaviors, and physiological health were examined as potential factors contributing to race differences in elevated CRP. RESULTS: Median CRP levels (interquartile range) were 1.67 (3.03) mg/L in whites and 2.62 (4.95) mg/L in blacks. Results from random effects logistic regression models showed that blacks had significantly greater odds of elevated CRP than whites (odds ratio = 2.58; 95% confidence interval [CI] = 2.20-3.02). Results also showed that racial difference in elevated CRP varied significantly by sex (predicted probability [PP] [white men] = 0.28 [95% CI = 0.27-0.30]; PP [black men] = 0.38 [95% CI = 0.35-0.41]; PP [white women] = 0.35 [95% CI = 0.34-0.36]; PP [black women] = 0.49 [95% CI = 0.47-0.52]) and remained significant after risk adjustment. In men, the racial differences in elevated CRP were attributable to a combination of socioeconomic (12.3%) and behavioral (16.5%) factors. In women, the racial differences in elevated CRP were primarily attributable to physiological factors (40.0%). CONCLUSION: In the US older adult population, blacks were significantly more likely to have elevated CRP than whites; and the factors contributing to these differences varied in men and women. J Am Geriatr Soc 68362-369, 2020.