Epidemiologic aspects of lipid abnormalities.

Existing cholesterol guidelines aimed at preventing cardiovascular disease emphasize the role of total cholesterol (TC) and low-density lipoprotein (LDL) cholesterol in lipid management decisions, with a subsidiary role for high-density lipoprotein (HDL) cholesterol in guiding treatment and little role for triglycerides. In this article, epidemiologic evidence is reviewed relating to the independent value of lipid factors in prediction of cardiovascular disease risk, including TC, LDL cholesterol, HDL cholesterol, very-low-density lipoprotein (VLDL) cholesterol and triglycerides, LDL particle size ("pattern B"), and the TC/HDL-cholesterol ratio. Several observations are highlighted. Triglycerides appear to be an independent risk factor in specific populations. Postprandial triglycerides may be superior to fasting triglycerides as a predictor of risk. LDL particle size does not have independent predictive value after adjustment for triglycerides. Particular emphasis is placed on the observation that the single most predictive lipid factor is the TC/HDL-cholesterol ratio, which implicitly incorporates information on both LDL and triglycerides in the numerator. This is the best predictor both of outcome and of treatment benefit, and its predictive value appears to be maintained into older age. It is concluded that increasing emphasis should be placed on the TC/HDL cholesterol ratio in epidemiologic analyses and in monitoring patients on therapy for dyslipidemia.