Growth Hormone Responses to Propranolol—Glucagon Stimulation: A Comparison with Other Tests of Growth Hormone Reserve

Abstract

The sequential administration of oral propranolol and intramuscular glucagon was evaluated as a test of growth hormone (GH) reserve in 73 children with growth retardation. Side effects related to hypoglycemia or to propranolol were noted in 13% of the patients studied. Twenty children who failed to attain GH levels > 6 ng/ml following arginine and insulin administration also failed to respond to propranololglucagon. Mean GH levels in 49 children who responded to propranolol-glucagon were 5.0 ng/ml at the beginning of the test, 10.9 ng/ml following propranolol, and rose to 20.8 ng/ml following glucagon. Ten of these children also received an arginine infusion followed by glucagon injection. Eight had a GH response to both stimuli, one failed to respond to arginine and another to glucagon. Mean GH responses to glucagon following arginine were significantly lower than to arginine following propranolol. Fourteen children with normal GH responses to propranolol-glucagon had blood drawn 60 and 90 min after the clinically observed onset of sleep on the night prior to and the night following propranololglucagon. Eleven had GH levels > 6 ng/ml in at least 1 of 4 samples, but only 2 had GH levels > 6 ng/ml in each of 4 samples. Four additional children had definite GH responses to propranolol-glucagon, but failed to respond to other stimuli. Clinical features in 4, and linear growth responses to exogenous human GH in 2 of 2 treated patients, were consistent with GH deficiency. The propranolol-glucagon test provides a potent and consistent stimulus to GH secretion in children. Those who show a normal response to propranolol-glucagon, but have other features which strongly suggest GH deficiency, should receive additional tests of GH release. (J Clin Endocrinol Metab37: 85, 1973).