Serum carotenoids and coronary heart disease. The Lipid Research Clinics Coronary Primary Prevention Trial and Follow-up Study

Abstract

To examine the relationship between total serum carotenoid levels and the risk of subsequent coronary heart disease (CHD) events. New analysis of a cohort from the Lipid Research Clinics Coronary Primary Prevention Trial and Follow-up Study (LRC-CPPT). The LRC-CPPT was a multicenter placebo-controlled trial of cholestyramine resin and CHD with a follow-up period of 13 years. Serum carotenoids were measured at baseline. The placebo group of the LRC-CPPT, which consisted of 1899 men aged 40 to 59 years with type II-a hyperlipidemia and without known preexisting CHD, cancer, or other major illnesses. Nonfatal myocardial infarctions and deaths attributable to CHD ascertained from hospital records, autopsy reports, and death certificates and reviewed by a panel of cardiologists. After adjustment for known CHD risk factors including smoking, serum carotenoids were inversely related to CHD events. Men in the highest quartile of serum carotenoids had an adjusted relative risk (RR) of 0.64 (95% confidence interval [CI], 0.44 to 0.92) compared with the lowest quartile. For men who never smoked, this RR was 0.28 (95% CI, 0.11 to 0.73). The LRC-CPPT participants with higher serum carotenoid levels had a decreased risk of incident CHD. This finding was stronger among men who never smoked.