Effect of propranolol on plasma growth hormone response in insulin-induced hypoglycemia in thyrotoxic patients.

Abstract

ABSTRACT Twenty-three control subjects and 26 thyrotoxic patients had plasma growth hormone levels estimated during the standard insulin tolerance test (ITT). The arithmetic and geometric means of the maximum plasma growth hormone levels in the thyrotoxic group were significantly lower than the corresponding values in the control group. The possibility that a less pronounced hypoglycemia in the thyrotoxic group was responsible for this difference was excluded by comparing the maximum plasma growth hormone responses of the thyrotoxic patients with a minimum blood glucose level less than 30 mg% and those of the controls with a comparable degree of hypoglycemia. The thyrotoxic patients also showed a less sustained rise in plasma growth hormone in response to insulin-induced hypoglycemia. β-adrenergic blockade increased the plasma growth hormone response to hypoglycemia in both the thyrotoxic patients and the controls, but the rise was higher in the latter. β-adrenergic blockade also failed to restore to norm...