Comparison of growth hormone sleep release and responses to pharmacological tests

The spontaneous release of growth hormone (GH) during nocturnal sleep was studied at age 5-19 years in 44 male and 15 female patients with severe growth retardation (-2.1 to -6.5 SD) among whom 43 were prepubertal and 16 pubertal. Comparison with the results of classical stimulation tests with ornithine, arginine and/or insulin showed good agreement in cases of classical hypopituitarism (n = 14) as in patients who seemed to be endocrinologically normal (n = 27). In 18 patients (31%) there was a discrepancy between sleep release and responses of GH to stimulation test: treatment with hGH was available in only 4 of these children and enhanced sharply their growth rate. It is suggested that a large span of intermediary situations exists between normal GH secretion and complete GH deficiency, deserving a controlled therapeutic trial with hGH.