Diagnosis of growth hormone deficiency with the growth hormone releasing factor GRF 1-40. The potentials and limits

Abstract

Eleven patients with constitutionally delayed development, seven patients with idiopathic growth hormone deficiency and ten patients with craniopharyngeoma received growth hormone releasing factor GRF 1-40 in a dose of 1 micrograms/kg body weight as a bolus injection. In the patients with constitutionally delayed development, a mean maximum HGH value of 86.7 microU/ml was measured 30 minutes after GRF injection. Considerably higher HGH stimulation values were thus obtained after GRF than with conventional stimulation methods. In the patients with idiopathic growth hormone deficiency or craniopharyngeoma, there was mostly only a slight rise of the growth hormone level with a delayed onset. Merely two patients with craniopharyngeoma could be adequately stimulated in accordance with conventional criteria (HGH greater than 12 microU/ml), although their values also remained markedly below those of the patients with constitutionally delayed development. Both patients had somatomedin C values which were below that normal for their age; together with the delayed rise in HGH after GRF, this allowed diagnosis of growth hormone deficiency.