C-reactive Protein and Coronary Artery Calcification: The Study of Inherited Risk of Coronary Atherosclerosis (SIRCA)

Objective: Circulating levels of C-reactive protein (CRP) predict cardiovascular events. In contrast, an association between CRP and direct measures of atherosclerosis has not been established clearly. In the largest study to date, we examined the association of plasma CRP with coronary artery calcification (CAC) in 914 asymptomatic subjects in the Study of Inherited Risk of Coronary Atherosclerosis (SIRCA).

Methods And Results: In age-adjusted, cross-sectional analysis, there was a weak association between plasma CRP levels and CAC in women (odds ratio [OR] for ordinal regression, 1.1 [1.04 to 1.17] per 1.0 mg/L increase in CRP; P=0.005) but not in men. The association between CRP and CAC in women remained significant after adjusting for traditional risk factors (OR, 1.08 [1.00 to 1.14]; P=0.048) but was lost after further adjustment for body mass index (BMI) (OR, 1.02 [0.94 to 1.08]; P=0.7).

Conclusions: In SIRCA, CRP was not associated with CAC in men, and a weak association in women was lost after adjustment for BMI. The relation between CRP and clinical events might not be related to atherosclerotic burden. Measures of inflammation, such as CRP, and indices of atherosclerosis, such as CAC, are likely to provide distinct information regarding cardiovascular risk.