Improvement of the Plasma Lipoprotein Pattern After Institution of Insulin Treatment in Diabetes Mellitus

Plasma lipids and lipoproteins were studied in 26 nonobese diabetic patients, either newly diagnosed or unsatisfactorily controlled by oral antidiabetic treatment. Measurements were performed before and 3-4 mo after the institution of insulin treatment. In a subgroup of seven patients, the activities of lipoprotein lipase (LPL) and hepatic lipase (HL) in postheparin plasma and the elimination rate of exogenous triglyceride were also monitored. After beginning insulin treatment, diabetic control was improved as demonstrated by decreasing levels of HbA1. Mean plasma cholesterol and triglyceride levels decreased by about 10% (P less than 0.01) and 40% (P less than 0.05), respectively. The decrease in plasma cholesterol was largely accounted for by a fall in LDL cholesterol levels (-8%, P less than 0.05), while plasma HDL cholesterol concentrations increased by about 12% (P less than 0.01). The elimination rate of exogenous triglycerides increased significantly. There was a suggestive, but not significant, increase in LPL activity while the HL activity remained unchanged. It is concluded that the improved diabetic control after institution of insulin treatment results in a significant improvement of the plasma lipoprotein profile. Since the improvement of the lipoprotein pattern is not strictly correlated to the amelioration of indices reflecting glucose transport, we suggest that the plasma lipoprotein pattern may provide an additional tool for monitoring the degree of control in diabetes mellitus.