Growth Hormone and Glucose Interrelationships in Diabetes: Studies with Insulin Infusion During Continuous Blood Glucose Analysis

To examine changes in plasma levels of human growth hormone (HGH) in severe diabetics under conditions resembling hypoglycemic reactions, 8 diabetics and 6 normal subjects were given insulin infusions at a constant rate during continuous automated blood glucose (BG) analysis. HGH was determined by radioimmunoassay at frequent intervals. All subjects tested who reached a BG nadir of 35 mg/100 ml had HGH increases. Other HGH increases occurred also during hyperglycemia in 7 tests, but only in diabetics. Mean increases in plasma HGH were similar in normals and in diabetics and whether during hypoglycemia or during hyperglycemia. No hyperglycemic or hypoglycemic effect of HGH increases was discernible. The method proved to be uniquely suited for exploring HGH and BG changes during the infusion of insulin. Diabetics differed from normals by augmenting circulating levels of HGH during hyperglycemia, whether or not BG was decreasing at the time the observations were made.