Dual secretagogue drive of burst-like growth hormone secretion in postmenopausal compared with premenopausal women studied under an experimental estradiol clamp

J Clin Endocrinol Metab. 2004 Sep;89(9):4746-54. doi: 10.1210/jc.2004-0424.

Abstract

We show that in an experimentally enforced estradiol-predominant milieu, postmenopausal compared with premenopausal women maintain 1) decreased fasting GH and IGF-I concentrations, 2) reduced basal and pulsatile GH secretion, and 3) attenuated GH secretion after maximal stimulation by the paired secretagogues l-arginine/GH-releasing peptide (GHRP)-2, l-arginine/GHRH, and GHRP-2/GHRH. These foregoing outcomes are selective, because menopausal status did not determine mean GH secretory-burst frequency or peptide-induced waveform shortening. Abdominal visceral fat mass predicted up to 25% of the variability in fasting and stimulated GH secretion in the combined cohorts under fixed systemic estradiol availability. Accordingly, as much as three-fourths of interindividual differences in burst-like GH secretion among healthy pre- and postmenopausal women arise from age-related mechanisms independently of short-term systemic estrogen availability and relative intraabdominal adiposity.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Arginine / pharmacology
  • Estradiol / pharmacology*
  • Female
  • Growth Hormone-Releasing Hormone / pharmacology
  • Human Growth Hormone / metabolism*
  • Humans
  • Insulin-Like Growth Factor I / analysis
  • Middle Aged
  • Oligopeptides / pharmacology
  • Postmenopause / metabolism*
  • Premenopause / metabolism*

Substances

  • Oligopeptides
  • Human Growth Hormone
  • Estradiol
  • Insulin-Like Growth Factor I
  • Growth Hormone-Releasing Hormone
  • Arginine
  • growth hormone-releasing peptide-2