Gender and C-reactive protein: data from the Multiethnic Study of Atherosclerosis (MESA) cohort.

Background: American Heart Association/Centers for Disease Control and Prevention guidelines support the measurement of C-reactive protein (CRP) to further risk stratify individuals at intermediate risk (10%-20% 10-year risk) for heart disease. Determining gender-specific differences in CRP may alter how CRP levels are interpreted and used to determine risk.

Methods: MESA is a prospective cohort consisting of 6814 men and women aged 45 to 84 years recruited from 6 US communities. Nonparametric analyses were performed to determine differences in CRP levels by gender in the entire cohort and after stratifying by use of estrogen medication (n = 944). Stratifying by median body mass index (BMI) and generalized linear models were also used to account for confounding variables associated with CRP.

Results: Overall, women had substantially higher median CRP levels compared with men (2.56 vs 1.43 mg/L, P < .0001). After excluding women using estrogen and individuals with CRP >10 mg/L, median CRP levels remained higher in women compared with men (1.85 vs 1.33 mg/L, P < .0001). When participants were stratified into high and low BMI groups, the gender difference in CRP levels remained. This pattern of higher CRP levels in women was consistent across all ethnic subgroups even after multivariable adjustment.

Conclusions: C-reactive protein levels were higher in women compared with men despite accounting for BMI and other common confounding variables. This gender difference was maintained across all ethnic subgroups. These results suggest that evaluation of gender-specific CRP cut points to determine cardiovascular risk should be considered.