Race and gender differences in C-reactive protein levels

Abstract

Objectives: This study sought to determine whether there are race and gender differences in the distribution of C-reactive protein (CRP) levels.

Background: Few data are available comparing CRP distributions in different race and gender groups. Recent clinical practice recommendations for CRP testing for cardiovascular risk assessment suggest a uniform threshold to define high relative risk (>3 mg/l).

Methods: We measured CRP in 2,749 white and black subjects ages 30 to 65 participating in the Dallas Heart Study, a multiethnic, population-based, probability sample, and compared levels of CRP between different race and gender groups.

Results: Black subjects had higher CRP levels than white subjects (median, 3.0 vs. 2.3 mg/l; p < 0.001) and women had higher CRP levels than men (median, 3.3 vs. 1.8 mg/l; p < 0.001). The sample-weight adjusted proportion of subjects with CRP levels >3 mg/l was 31%, 40%, 51%, and 58% in white men, black men, white women, and black women, respectively (p < 0.05 for each group vs. white men). After adjustment for traditional cardiovascular risk factors, estrogen and statin use, and body mass index, a CRP level >3 mg/l remained more common in white women (odds ratio [OR] 1.6; 95% confidence interval [CI] 1.1 to 2.5) and black women (OR 1.7; 95% CI 1.2 to 2.6) but not in black men (OR, 1.3; 95% CI, 0.8 to 1.9) when compared with white men.

Conclusions: Significant race and gender differences exist in the population distribution of CRP. Further research is needed to determine whether race and gender differences in CRP levels contribute to differences in cardiovascular outcomes, and whether thresholds for cardiovascular risk assessment should be adjusted for different race and gender groups.