The very low- and
low-density lipoprotein fractions were isolated from 16 normolipidaemic Type 2 (non-
insulin-dependent) diabetic patients in good to fair glycaemic control and from corresponding age-, sex-, and race-matched, non-diabetic control subjects. Rates of
cholesteryl ester synthesis averaged 268 +/- 31 vs 289 +/- 40 pmol 14C-cholesteryl
oleate.mg cell protein-1.20 h-1 for very low- and 506 +/- 34 vs 556 +/- 51 pmol 14C-cholesteryl
oleate.mg cell protein-1.20 h-1 for
low-density lipoproteins isolated from the Type 2 diabetic patients and control subjects, respectively, when they were incubated with human macrophages. A group of approximately one-third of the patients was selected for separate analyses because
very low-density lipoproteins isolated from these patients did stimulate more
cholesteryl ester synthesis when incubated with macrophages. There were no significant differences in the
lipid composition of the
lipoproteins isolated from the three groups of subjects. The relative proportion of
apoprotein C to
apoprotein E was significantly decreased (p less than 0.002) in the
very low-density lipoproteins from diabetic patients and was further decreased in samples from these selected diabetic patients. The
apoprotein C-I content of
very low-density lipoproteins isolated from diabetic patients was increased compared to control subjects and was further increased in samples from the selected diabetic patients (p less than 0.02). There were no significant differences in the proportions of
apoproteins C-III-0, C-III-1, or C-III-2 among the three groups. These studies suggest that in normolipidaemic Type 2 diabetic patients, the
apoprotein composition of VLDL is abnormal and this may alter VLDL macrophage interactions and thus contribute to the increased prevalence of
atherosclerosis in diabetic patients.