Growth hormone response following growth hormone releasing hormone injection in thalassemia major: influence of pubertal development.

Thirty-five patients with thalassemia major, aged 7 to 21 years, were studied to define the relationship between the pubertal development and the growth-hormone (GH) secretion during sleep, after administration of GH-releasing factor (hpGRF 1-44), and betaxolol-glucagon or arginin-insulin. Pubertal development was classified as being appropriate or delayed for chronological age. GH response to pharmacological stimuli and during sleep was not linked to the pubertal development according to the chronological age. The peak of GH secretion after GHRH injection was significantly delayed in thalassemic patients with retarded puberty. The integrated secretion of GH during the 120-min test was slightly but not significantly reduced in these patients. The prepubertal pattern of GHRH response was restored in the patients receiving substitutive therapy by HCG or testosterone. The alteration of GH response to GHRH in thalassemic patients is likely to be only due to delayed puberty and decreased endogeneous GHRH secretion since it is corrected by androgen or gonadotropin replacement.