Alternation in both insulin release and its hypoglycemic effects in atopic bronchial asthma.

In 31 patients with atopic bronchial asthma in clinical remission and in 21 healthy sex- and age-matched subjects, the responses to intravenous tolbutamide (1.0 gm) and insulin (0.1 U/kg) were studied over a period of 2 hr. In response to tolbutamide, asthmatics released significantly less insulin, but their blood glucose levels did not differ from those of controls. Asthmatics also reacted to tolbutamide-induced hypoglycemia with significantly greater output of growth hormone to blood. Following intravenous injection of insulin, the recovery of the blood glucose concentrations was significantly reduced in asthmatic patients. More economical use of insulin and increased responsiveness to its hypoglycemic action, together with the well-known reduction in hypoglycemic effects of catecholamines in bronchial asthma, might explain why asthmatics rarely develop diabetes mellitus.