Abstract MP11: Elevated High Sensitivity C-Reactive Protein as a Risk Marker of the Attenuated Relationship Between Serum Cholesterol and Coronary Heart Disease at Older Age - Atherosclerosis Risk in Communities Study
Introduction: The relationship between serum cholesterol and coronary heart disease (CHD) risk is attenuated at older age, making it difficult to estimate risk in this age group.
Hypothesis: We hypothesized that high sensitivity C-reactive protein (hs-CRP) would identify two subgroups of older individuals (≥65 years): one in whom cholesterol is less predictive of CHD and one in whom it is equally predictive compared to younger individuals.
Methods: We calculated crude incident rates per 1,000 person-years and used adjusted Cox proportional hazards models to analyze cholesterol as a predictor of CHD in 8,947 participants with no known history of CHD who were stratified by age (53-64 or 65-75 years) and hs-CRP level (<2 or ≥2 mg/L) at baseline.
Results: Among younger participants, total serum cholesterol was significantly associated with an increased risk of CHD regardless of hs-CRP group HR 1.39 (95% CI 1.20-1.61) for hs-CRP <2 mg/L and HR 1.37 (95% CI 1.22-1.53) for hs-CRP ≥2 mg/L. Among older participants with a low hs-CRP, total cholesterol had a similar association with CHD, HR 1.46 (95% CI 1.24-1.71), as in younger individuals. In contrast, among older individuals with higher hs-CRP, the association of CHD with total cholesterol was attenuated, HR 1.14 (95% CI 1.00-1.29), p-value for interaction = 0.02. Similar trends were observed between age groups and hs-CRP categories for LDL cholesterol.
Conclusions: Among individuals aged 65-75 years, the association of cholesterol with CHD was strong in those with a low hs-CRP and weak in those with an elevated hs-CRP. Thus, in addition to its use as a risk factor, an elevated hs-CRP could be useful for stratifying the elderly population to aid in the interpretation of serum cholesterol in the prediction of subsequent CHD risk.
- © 2013 by American Heart Association, Inc.