Quantitative and qualitative lipoprotein abnormalities in diabetes mellitus

In people with diabetes, the concentration of an individual lipoprotein or apolipoprotein can be highly variable and is totally different in the two major forms of the disease. Alterations in the concentrations of major lipids and lipoproteins are well characterized in both IDDM and NIDDM. In general, the lipoprotein pattern is antiatherogenic in individuals with IDDM who are treated and have optimal glycemic control. In contrast, NIDDM is associated with atherogenic changes of serum lipids and lipoproteins regardless of the mode of treatment. In people with both types of diabetes, the distribution of apoE phenotype seems to be similar to that in nondiabetic populations. IDDM patients with microalbuminuria show atherogenic changes of lipoproteins and have elevated levels of Lp(a), which is a risk factor of coronary artery disease. Whether glycemic control influences the concentration of Lp(a) is still an open question. An important issue is that the concentration of a lipoprotein can be normal without excluding compositional abnormalities that are potentially atherogenic. Such alterations are present in people with both IDDM and NIDDM. Consequently, it has been questioned whether the target values to start treatment should be lower in diabetic than in nondiabetic populations.