Glucocorticoids and growth

Glucocorticoids play a critical role in the regulation of the hypothalamic-somatotropic-insulin-like growth factor axis. These steroids enhance growth hormone gene transcription and increase growth hormone-releasing hormone receptor synthesis. However, glucocorticoid excess inhibits somatic growth. Evidence to date suggests that this is in part due to impaired growth hormone secretion observed during hypercortisolism as well as impaired actions of growth hormone at the peripheral level. This includes impaired spontaneous growth hormone secretion, suppressed growth hormone responses to a number of stimuli, including growth hormone-releasing hormone, and increased insulin-like growth factor inhibitors and binding proteins. The inhibitory effect of the glucocorticoids appears to be due to increased hypothalamic somatostatin tone and inhibition of insulin-like growth factor bioactivity.