Serum C-reactive protein and self-reported stroke: findings from the Third National Health and Nutrition Examination Survey.

C-reactive protein may predict the risk of coronary heart disease, but its association with stroke has not been well studied. We used data from the Third National Health and Nutrition Examination Survey, conducted from 1988 to 1994, to examine the association between serum C-reactive protein concentrations and self-reported past history of stroke among 8850 US men and women aged >/=40 years. The unadjusted geometric mean of C-reactive protein concentration was higher among participants with stroke than those without stroke (0. 45+/-0.02 versus 0.32+/-0.01, P<0.001). After adjusting for age, sex, race or ethnicity, education, smoking status, systolic blood pressure, serum cholesterol, high density lipoprotein cholesterol, history of diabetes mellitus, body mass index, and physical activity, the odds ratio for stroke among participants with C-reactive protein concentrations >/=0.55 mg/dL compared with participants with concentrations </=0.21 mg/dL was 1.71 (95% CI 1.11 to 2.64 [odds ratio per mg/dL 1.19, 95% CI 1.05 to 1.34]). These cross-sectional data support findings from other studies suggesting that C-reactive protein concentration may be a risk factor or marker for stroke in the US population.