[Effect of insulin sensitivity on the occurrence of early-morning hyperglycemia in patients treated with insulin].

The study was aimed at elucidation of the effect of insulin-sensitivity on the occurring of the dawn phenomenon. Diabetic patients were investigated in whom the fasting glycaemia was often higher than 17 mmol/l (300 mg%). In all patients the euglycaemic state was maintained by a continuous i.v. infusion of insulin using a micropump and a changing infusion of glucose using Biostator. A slight increase in the insulin-sensitivity was seen in the early morning in 3 patients in whom the glucose consumption during the constant insulin infusion was 4 mg/min/kg b.w. Among 7 patients with lower glucose consumption in 6 a markedly low insulin-sensitivity was seen at down. The investigations allow to assume that the dawn phenomenon occurs mainly in patients with uncompensated diabetes which induces changes in insulin-sensitivity.