Cardiovascular Disease in U.S. Patients With Metabolic Syndrome, Diabetes, and Elevated C-Reactive Protein

OBJECTIVE: C-reactive protein (CRP) independently predicts cardiovascular disease (CVD); whether it can stratify risk in those with metabolic syndrome and diabetes is not well documented. We evaluated whether elevated CRP levels modify the relationship of metabolic syndrome and diabetes with CVD in U.S. adults. RESEARCH DESIGN AND METHODS: In a cross-sectional study of 3,873 subjects (weighted to 156 million) aged >/=18 years participating in the National Health and Nutrition Examination Survey 1999-2000, subjects were classified as having diabetes, metabolic syndrome according to modified National Cholesterol Education Program criteria, or neither condition by low (<1 mg/l), intermediate (1-3 mg/l), or high (>3 mg/l) CRP levels. Logistic regression examined the odds of CVD by disease condition and CRP group. RESULTS: After adjusting for age, sex, smoking, and total cholesterol, compared with those with neither metabolic syndrome nor diabetes and low CRP levels, the odds of CVD were 1.99 (95% CI 1.10-3.59) for those with no disease and high CRP levels and 2.67 (1.30-5.48) for those with metabolic syndrome and intermediate CRP. Persons with metabolic syndrome but high CRP had an odds ratio (OR) of 3.33 (1.80-6.16), similar to those with diabetes and low CRP (3.21 [1.27-8.09]). The likelihood of CVD was highest in those with diabetes who had intermediate CRP levels (6.01 [2.54-14.20]) and in those with diabetes and high CRP (7.73 [3.99-14.95]). CONCLUSIONS: In this cross-sectional analysis, CVD is more common in those with metabolic syndrome or diabetes who have elevated CRP. Stratification by CRP may add prognostic information in patients with metabolic syndrome or diabetes.