The response of glucose, insulin and FFA to intravenous glucose and glucagon in elderly subjects in the course of morning and afternoon tests.

The response of glucose, FFA and immunoreactive insulin to intravenous glucose and glucagon was examined in 6 apparently healthy subjects aged 67-77 years at 08(00) and 18(00) with a 3 day interval. The subjects, fasted 12 h before each test, received 0.5 g/kg of glucose i.v. and, 40 min after glucose, 1 mg glucagon i.v. The results confirmed, also in aged subjects, an impaired glucose tolerance in the afternoon test, as previously reported in the adult subject. The insulin response was delayed in the afternoon test, but the total incremental area was not significantly reduced. There was not a clearcut difference in the pattern of FFA response. The results could be a further confirmation of the central role of insulin response as a cause of impaired glucose tolerance in the afternoon also in subjects aged over 65 years.