Abstract
In a previous paper it was shown that 15 out of 85 healthy subjects with a normal intravenous glucose tolerance demonstrated a low plasma insulin response to glucose infusion which was similar to that obtained in diabetic subjects. In the present paper it has been shown that the type of insulin response to glucose infusion was the same when the test was repeated. Low insulin responders to glucose infusion, as a group, also showed low insulin response to intravenous tolbutamide and oral glucose. This indicates that the type of insulin response is characteristic for a given subject irrespective of the stimulation used. There seemed to be no difference in the occurrence of diabetes in the family history of the groups of low and high insulin responders.