Prevalence and Risk Factor Correlates of Elevated C-Reactive Protein in an Adult Australian Population

Abstract

Measurement of the inflammatory biomarker C-reactive protein (CRP) is advocated for coronary heart disease risk assessment. The distribution and correlates of CRP in the general population should be known before it is used in clinical practice. CRP was measured in 1,761 men and 2,248 women aged 25 to 84 years who attended the 1994/1995 Busselton Health Survey. Prevalences of increased CRP >3 mg/L for age groups 25 to 39, 40 to 59, and 60 to 84 years were 15.7%, 20.6%, and 38.7%, respectively, in men and 21.2%, 22.1%, and 33.7%, respectively, in women not on hormone therapy. Logistic regression analysis identified independent predictors of increased CRP in men as obesity (odds ratio [OR] 3.5, 95% confidence interval [CI] 2.4 to 5.0), smoking (OR 3.1, 95% CI 2.1 to 4.5), hypertension (OR 1.6, 95% CI 1.1 to 2.3), and low high-density lipoprotein cholesterol (OR 1.4, 95% CI 1.0 to 1.8). In women, predictors were obesity (OR 7.8, 95% CI 5.8 to 10.6), hypertension (OR 1.4, 95% CI 1.0 to 1.9), high triglycerides (OR 1.6, 95% CI 1.1 to 2.4), vigorous exercise (OR 0.7, 95% CI 0.5 to 0.9), oral contraceptive use (OR 4.6, 95% CI 3.3 to 6.5), and hormone replacement therapy (OR 2.8, 95% CI 1.9 to 4.0). Overall, risks of increased CRP attributable to the presence of an abnormal or borderline coronary heart disease risk factor were 59% for men and 64% for women. In conclusion, despite gender-related differences in cardiovascular risk, increased CRP occurred commonly in men and women. Because increased CRP was largely attributable to conventional coronary heart disease risk factors, measurement of CRP may have limited utility for risk screening and primary prevention.