Metoclopramide stimulation: a test of growth hormone reserve in adolescent males.

A comparison was made between the growth hormone (GH) response to metoclopramide ('Maxolon'--Beecham Laboratories) and insulin induced hypoglycaemia in thirty-five short adolescent males. Both tests initially caused adequate release of GH from the pituitary gland in 86% of those subjects who had normal GH reserve. The peak growth hormone responses of the two tests were similar in magnitude and were strongly correlated (r = 0.80, P less than 0.001). Both tests raised serum GH to a similar degree in twenty-nine out of the thirty-five boys (83%), but four boys who responded satisfactorily to hypoglycaemia failed to respond to metoclopramide (MCP) stimulation, and two boys who failed to respond to hypoglycaemia responded satisfactorily to MCP stimulation. MCP stimulation does not require prior preparation of the patient and is relatively free of side effects. Consequently, it is suggested that MCP stimulation may be a useful 1 hour out-patient test for growth hormone deficiency in this relatively common group of patients.