Investigations of tolerance to oral and intravenous glucose, intravenous and intra-arterial insulin, intravenous tolbutamide, and to subcutaneous glucagon were made in twelve patients with hyperadrenocorticism. The findings varied among patients, but certain trends were apparent.
Fasting blood sugar concentrations tended to be low. The results of oral glucose tolerance teats were diabetic in eleven patients. The rate of glucose disappearance during glucose loading was normal or increased in all. Intravenous tolbutamide caused prolonged hypoglycemia in three of five patients. Hypoglycemia after intravenous and intra-arterial insulin was decreased. Depression of serum phosphorus was less than normal. Glucagon caused a rise in blood sugar above that of normals.
The findings suggest that there is a normal or even increased rate of glucose utilization in clinical endogenous hyperadrenocorticism. The data are compatible with the view that the action of insulin on muscle tissue may be decreased with shift to other areas, perhaps adipose tissue.