The pancreatic beta-cell response to intravenous administration of glucose in elderly subjects.

Abstract

AbstractA study was made of the serum insulin level after the intravenous administration of glucose (0.33 gm/ kg) in two groups of normal subjects—18 in the 60–85 age bracket, and 16 in the 23–45 age bracket. All had a normal coefficient of glucose utilization and a normal blood glucose curve after intravenous administration of glucose. Serum insulin was assayed by the radio‐immunological method, with use of an ion exchange resin. Blood samples were drawn at 2, 5, 10, 30, 45 and 60 minutes after the end of the glucose infusion.In the elderly subjects the maximal value was reached only after 5 minutes and the mean value was 39± 9 µU/ml (range, 27–50), whereas in the younger subjects the serum insulin level rose immediately, reaching a maximal value 2 minutes after glucose infusion, the mean value being 54 ± 10 µU/ml (range, 42–66). Thus the response of the pancreatic beta‐cells to functional stimulation in the elderly subjects was slower and weaker than in the younger ones, although there was no decrease in glucose tolerance. There were no differences with respect to the peripheral utilization of insulin.