Insulin secretion and erythrocyte insulin binding in Cape coloured non-obese non-insulin-dependent diabetes in the young: effects of sulphonylurea therapy.

Studies were performed on 10 Cape coloured non-obese NIDDY (non-insulin-dependent diabetes in the young) patients and 6 controls of similar age, sex and weight. Fasting plasma glucose, glucose assimilation rate, insulin secretion in response to an intravenous glucose tolerance test and percentage binding of radiolabelled 125I-insulin to red blood cells were assessed in all patients before and after one month of glibenclamide treatment. Both insulin secretion (P less than 0.01) and erythrocyte insulin receptor binding (P less than 0.01) were significantly reduced when compared to controls. Although glibenclamide markedly improved the second phase of insulin secretion, the intravenous glucose tolerance test stimulated the total insulin secretion to only 40% of control values. The percentage binding of 125I-insulin to red cell receptors improved considerably with therapy, and did not differ significantly from that of control values.