Insulin Treatment and Diabetic Vascular Complications

To the Editor.—  University Group Diabetes Program (UGDP) investigators recently reported (240:37, 1978) that the cardiovascular death rate in two groups of patients with mild, maturity-onset diabetes treated with insulin did not differ from that of subjects receiving placebo medication even though fasting blood glucose levels were significantly lower in one group of insulin-treated subjects (insulin variable) than in the placebo group. On the basis of these observations they concluded that administration of insulin to normalize blood glucose does not protect asymptomatic maturity-onset diabetics from cardiovascular complications of diabetes and that there is no reason, therefore, to administer insulin for that purpose. After careful examination of patient data recently released by the UGDP coordinating center, we are convinced that this conclusion is erroneous and is attributable to inclusion of numerous inappropriate (in our opinion) subjects in the data analysis.Since the primary objective of the study was to determine whether