Normal growth hormone (GH) response to GH-releasing hormone in children with thalassemia major before puberty: a possible age-related effect

J Clin Endocrinol Metab. 1989 Aug;69(2):453-6. doi: 10.1210/jcem-69-2-453.

Abstract

The plasma GH response to a single iv bolus dose of 2 micrograms/kg BW synthetic GHRH-(1-44)NH2 was evaluated in 13 prepubertal children with thalassemia major (mean age, 7.6 +/- 0.8 yr) with growth retardation and in 15 prepubertal children with nonendocrine short stature. All of the patients showed a significant increase in plasma GH concentration, with a mean peak of 31.4 +/- 4.5 micrograms/L at 15 min (P less than 0.001 vs. basal values; range, 18.4-65 micrograms/L) after GHRH, which was not different from that of the control group of idiopathic short stature children (40.1 +/- 3.4 micrograms/L; range, 21-65.4 micrograms/L). All but 1 of the thalassemic patients had a normal GH response to the arginine-insulin stimulation test. The mean plasma insulin-like growth factor-I level was low (0.12 +/- 0.05 U x 10(3)/L; range, less than 0.02-0.61 U x 10(3)/L). Analysis of these results as well as previously reported data indicating that older thalassemic patients have an impaired GH response indicates that there may be an age-related pituitary and/or hypothalamic dysfunction in thalassemic children. This study also confirms that the insulin-like growth factor-I decrease occurs before any alteration in GH secretion. These changes might play a role in the early growth retardation that occurs in these patients.

MeSH terms

  • Age Factors
  • Child
  • Child, Preschool
  • Dwarfism / blood
  • Dwarfism / complications
  • Female
  • Growth Hormone / blood*
  • Growth Hormone-Releasing Hormone / pharmacology*
  • Humans
  • Insulin-Like Growth Factor I / blood
  • Male
  • Puberty*
  • Thalassemia / blood*
  • Thalassemia / complications
  • Thyrotropin / blood
  • Thyroxine / blood

Substances

  • Insulin-Like Growth Factor I
  • Thyrotropin
  • Growth Hormone
  • Growth Hormone-Releasing Hormone
  • Thyroxine