Insulin resistance following nocturnal hypoglycaemia in insulin-dependent diabetes mellitus.

Glucose metabolism was studied by a somatostatin-insulin-glucose infusion test (SIGIT) for 8 h in 7 male patients with insulin-dependent diabetes mellitus. They were investigated on two occasions in random order, with and without preceding hypoglycaemia induced between 3.00 and 4.00 h. SIGIT was started at 7.00 h when blood glucose was restored to normal and the counterregulatory hormones had returned to basal values. As expected, hypoglycaemia evoked an enhancement of the plasma levels of GH (43.7 +/- 10.1 vs 4.4 +/- 1.8 micrograms/l), cortisol (690 +/- 59 vs 140 +/- 32 nmol/l), glucagon (225 +/- 35 vs 143 +/- 25 ng/l), and epinephrine (3.80 +/- 1.00 vs 0.10 +/- 0.03 nmol/l). During the SIGIT, the levels of circulating free insulin and counterregulatory hormones were similar in the two tests notwithstanding that excessive hyperglycaemia appeared when SIGIT was preceded by hypoglycaemia. The present study thus demonstrates that nocturnal hypoglycaemia induces insulin resistance in insulin-dependent diabetic patients not deprived of insulin.