LIPOPROTEIN METABOLISM IN NON-INSULIN-DEPENDENT DIABETES-MELLITUS

The risk and incidence of vascular disease in patients with non-insuli n-dependent diabetes mellitus (NIDDM) are higher than those of the non diabetic population. The modest changes in the concentration of plasma lipids that have been reported do not fully explain this increased ri sk of vascular disease in diabetics. However, there have been numerous reports of changes in the composition and structure of plasma lipopro teins in patients with NIDDM that render these lipoproteins more ather ogenic. Changes in the subpopulation distribution of plasma low-densit y lipoprotein and high-density lipoprotein, which have been shown to b e associated with vascular disease, have been also observed in patient s with NIDDM. Although the precise mechanisms that underlie the origin ation of alterations in the subpopulation distribution of plasma lipop roteins have not been fully elucidated, evidence strongly suggests tha t changes in the activities of key enzymes in lipoprotein metabolism m ay contribute to the altered lipoproteins. This review describes the e ffects of diabetes, along with the confounding effects of obesity and insulin resistance, on the metabolism of plasma lipoproteins. in addit ion, the changes in the function of enzymes that are involved in the m etabolism of cholesterol and triglycerides of circulating lipoproteins that occur in NIDDM are presented. Although new insight on the effect s of diabetes and its complications on the metabolism of lipoproteins has been gained, there are still gaps that need to be filled to comple te our understanding of the strong relationship between diabetes and v ascular disease. (C) Elsevier Science Inc.