[Triglyceride-rich lipoproteins as risk factors for atherosclerosis]

There is more and more epidemiological evidence elevated plasma triglyceride concentrations increase the risk for atherosclerosis especially for coronary heart disease. Since triglyceride-rich lipoprotein fractions also contain different concentrations of cholesterol and since the metabolism of triglyceride-rich lipoproteins is not independent from the metabolism of HDL, the variables HDL-cholesterol and LDL-cholesterol (respectively total-cholesterol) must be taken into account when evaluating the atherosclerotic risk of triglyceride-rich lipoproteins. This epidemiological evidence is underlined by clinical observations about the high incidence of atherosclerosis and coronary heart disease in relation to abnormalities in the triglyceride-rich lipoprotein metabolism as in patients with diabetes mellitus, familial dysbetalipoproteinemia and familial combined hyperlipidemia. Very low density lipoproteins (VLDL), low density lipoproteins (LDL) and high density lipoproteins (HDL) from patients with hypertriglyceridemia are enriched in free and esterified cholesterol. This changed composition of these lipoprotein fractions leads to an increased elimination from the circulation via atherogenic macrophages and smooth muscles cell pathways. Successful treatment of hypertriglyceridemic states obviously normalizes the changed composition of the lipoprotein fractions and in consequence effects also the atherogenicity.