Interactions between glucocorticoids and the growth hormone-insulin-like growth factor axis.

Glucocorticoids in pharmacological doses interfere with the integrity of the somatotropics hormone axis. However, the apparent discrepancies between the in vitro and in vivo studies, short-term vs. long-term exposure, and species-specific changes complicate a clear assessment of these interactions. The growth-depressing effects of glucocorticoids are multifactorial and involve suppression of pituitary GH release by stimulating hypothalamic somatostatin tone, down-regulation of hepatic GH receptors, inhibition of GH bioactivity by the induction of IGF inhibitors, complex alteration of the IGFBP serum profile, and a direct suppressive effect on tissue matrix production and synthesis of local growth factors.