ALTERATIONS IN VERY LOW-DENSITY-LIPOPROTEIN SUBFRACTIONS IN NORMOTRIGLYCERIDEMIC NON-INSULIN-DEPENDENT DIABETICS

Lipid and apoprotein composition of four very low density lipoprotein (VLDL) subfractions decreasing in S(f) value were evaluated in the fasting state in 12 normolipidemic Pima Indians (6 M, 6 F, age 39 +/- 1.7 yrs) (mean +/- SEM) with non-insulin-dependent diabetes mellitus (NIDDM) in poor glycemic control (HbA1 9.8 +/- 2.9%) and in 14 normoglycemic Pima controls matched for age, BMI and lipid values. Total cholesterol (CHOL), triglyceride (TG), phospholipids (PL), total protein (TP), apo B, apo CII, apo CIII and apoE were assayed in total VLDL and in each of the four VLDL subfractions designed as A (S(f) > 400), B (S(f) 175-400), C (S(f) 100-175), and D (S(f) 20-100). Diabetics compared to nondiabetics had higher concentrations of all constituents of VLDL D, with the largest changes being in TG (38.0 +/- 3.8 vs 28.0 +/- 2.5 mg/dl, P < 0.04), PL (14.0 +/- 1.3 vs 10.0 +/- 1.0 mg/dl, P < 0.04), TP (9.8 +/- 0.8 vs 7.6 +/- 2.4 mg/dl, P < 0.05), apo B (6.3 +/- 0.5 vs 4.7 +/- 0.4 mg/dl, P < 0.03) and apoE (0.73 +/- 0.09 vs 0.52 +/- 0.04 mg/dl, P < 0.04). Since no difference was found between the groups in percentage composition of lipids or apoproteins in total VLDL and in all VLDL subfractions, the data suggest that in diabetics, even when normolipidemic, there is an increase in the number rather than in the composition of the smallest VLDL subfraction (VLDL D), which are usually considered to be more atherogenic.