Relative atherogenicity of different plasma lipoproteins.

Originally, data from the Framingham study appeared to show that serum lipoprotein fractions were no better in predicting coronary heart disease than the total serum cholesterol. More recently, the concentration of high density lipoprotein has been shown to exhibit a strong negative correlation with coronary heart disease, especially in the older age groups in which total serum cholesterol shows little or no correlation with clinical events. Biochemical mechanisms that might clarify the role of high density lipoprotein in atherogenesis are forthcoming. Another aspect of the lipoprotein-atherogenesis question pertains to the possible role of chylomicrons. Animal experiments show that cholesterol feeding is frequently accompanied by an increase in beta-migrating, very low density lipoproteins which appear to be chylomicron remnants. The atherogenic effect of serum low- and very low-density lipoproteins, including chylomicron remnants, appears to depend more on their contribution to the total cholesterol concentration than to their origin in liver versus intestines.