Glucose control of basal insulin secretion in diabetes.

The plasma insulin response to both a small increase and decrease in the plasma glucose has been studied in normal and diabetic, non-obese subjects. In a second investigation the plasma insulin concentrations were measured during a gradual reduction of the raised fasting plasma glucose of diabetes to normal levels. In both studies, diabetic patients were found to have a markedly impaired response of the fasting plasma insulin to small changes in plasma glucose. These results do not support the suggestion that stimulated and not basal insulin secretion is impaired in diabetes. Both modes of secretion are probably via the same B-cell release mechanism, which is deficient in diabetes. There was a gradation of response between maturity onset and juvenile onset diabetics.