Lipids, lipoproteins and apolipoproteins in type 1 (insulin-dependent) and type 2 (non-insulin-dependent) diabetes mellitus.

Total plasma cholesterol, triglycerides, VLDL-C, VLDL-TG, HDL-C and the apoproteins A-I, A-II, B and D were measured in 111 male non-obese diabetic patients and in 90 male control subjects of similar age and body weight distribution. Forty-eight patients had Type 1 (insulin-dependent diabetes) and 63 had Type 2 (non-insulin-dependent diabetes); all were in stable metabolic control while following an appropriate diet and therapy with insulin or oral hypoglycemic agents. HDL-C, apoA-I, apoB and the apoA-I/apoA-II ratio were significantly increased in the Type 1 patients, whereas the VLDL-C/VLDL-TG and LDL-C/apoB ratios were decreased significantly. Type 2 diabetics showed low HDL-C and low apoA-I/apoA-II ratio, while the values of apoA-I, A-II, D and the VLDL-C/VLDL-TG ratio were significantly higher than in controls. Type 1 diabetics in 'fair' metabolic control presented higher values of TG, VLDL-C, VLDL-TG and apoB than patients in 'good' control: lower values of apoA-I and of the ratios apoA-I/apoA-II, apoA-I/apoB and LDL-C/apoB were recorded in the same subgroup. In Type 2 diabetics no significant differences were observed according to metabolic control, with the exception of a higher apo-D value in subjects in 'fair' control. The data obtained support the view that good metabolic control may be important for the prevention of a relevant derangement of lipoprotein components, particularly in Type 1 patients.