C-Reactive Protein as a Predictor of Cardiovascular Risk in a Population With a High Prevalence of Diabetes

BACKGROUND: High-sensitivity C-reactive protein (CRP) has been investigated extensively as a marker for predicting the risk of cardiovascular disease (CVD). CVD accounts for a large proportion of mortality and morbidity in American Indians; we sought to test the association of CRP and CVD in a population-based American Indian cohort 45 to 74 years old. METHODS AND RESULTS: Of 3277 participants who were CVD-free at baseline, 542 had CRP >10 mg/L and were excluded from analysis; 50.1% of those included had diabetes. There were 343 CVD events among this cohort during a median follow-up of 6.2 years. Multiple CVD risk factors were used as covariates in Cox proportional-hazard models. After exclusions, the median CRP (3.2 mg/L) was higher than reported in many other populations. CRP predicted CVD in models adjusted for traditional risk factors, but not when albuminuria and fibrinogen were included. In subgroup analysis, CRP was strongly related to incident CVD among nondiabetic women participants, even after adjustment for traditional CVD risk factors and other indicators of inflammation. Conversely, CRP was elevated beyond the useful range of the American Heart Association/Centers for Disease Control and Prevention clinical guidelines in 16% of this population, and CRP was not predictive of CVD in important subgroups, such as those with diabetes. CONCLUSIONS: CRP was a predictor of CVD in this American Indian population with a high prevalence of diabetes and other risk factors. The predictive ability of CRP varies considerably among subgroups with different risk factor profiles.