Propranolol-Insulin Stimulation Test in the Diagnosis of Growth Hormone Deficiency[*]

Abstract

Intravenous injection of insulin during the infusion of propranolol was evaluated as a test for growth hormone (GH) reserve in 18 patients with short stature who failed to respond adequately to insulin alone. In control normal subjects tested, the propranolol-insulin stimulation test produced a significantly higher GH rise than did the standard insulin test. In 10 patients with pituitary dwarfism (organic or idiopathic hypopituitarism with multiple pituitary hormone deficiency), peak GH levels were less than 6 ng/ml in the standard insulin or arginine test and were less than 7 ng/ml in the propranolol-insulin test. On the other hand, 8 non-pituitary dwarfs (chromosome anomalies, constitutional dwarfism with congenital anomalies and deprivation dwarfism) who failed to show normal GH response in the standard insulin test, responded to propranolol-insulin with peak GH levels exceeding 10 ng/ml. Only 3 of these 8 patients attained peak GH levels over 9 ng/ml in the arginine test.

These results indicate that the propranolol-insulin test provides a potent and consistent stimulus to GH secretion and is therefore useful in the diagnosis of GH deficiency.

Key words

Growth Hormone - Propranolol - Insulin - Dwarfism

1 Presented in part at the IV International Congress of Endocrinology, Washington, D.C., June 1972.

1 Presented in part at the IV International Congress of Endocrinology, Washington, D.C., June 1972.