Plasma GH response to hpGRF-44 in normal children of short stature and patients with GH deficiency.

Synthetic human pancreatic GRF (hpGRF-44) was administered as an iv bolus to 139 normal children of short stature and 63 patients with GH deficiency. After a dose of 1 and 2 micrograms hpGRF-44/kg BW, mean plasma GH levels peaked at 15 and 30 min, respectively, with corresponding values of 32.2 +/- 3.6 and 31.8 +/- 2.4 (+/- SE) ng/ml in normal but short children. There were no differences according to sex or age in plasma GH response to hpGRF-44 between the ages of 4 and 18 years. A similar plasma GH response was observed when 2 micrograms hpGRF-44/kg BW was administered two hours after lunch. The overall plasma GH response was greater than that of insulin-induced hypoglycemia and was similar to that obtained in the glucagon-propranolol test. Thirty-five of 63 patients with GH deficiency did not respond to a 2 micrograms hpGRF-44/kg BW. However, plasma GH increases to greater than 5 ng/ml occurred in the remaining 28 patients. Their mean GH level reached a peak at 90 min with a value of 8.8 +/- 0.8 ng/ml. These results suggest that hpGRF-44 is useful for evaluating pituitary GH reserve in children of short stature and that some patients with GH deficiency, diagnosed on the basis of established tests, have GH responses to hpGRF-44.