Chronic administration of glucocorticosteroids (GCs) can have significant catabolic effects in vivo in a host of metabolic systems, including amino acid metabolism, skeletal muscle, bone and linear growth. GCs inhibit protein synthesis and increase protein breakdown at the skeletal muscle and whole-body level and impair growth hormone (GH) secretion and action. Conversely, GH and insulin-like growth factor I (IGF-I) are potent protein-anabolic and growth-promoting agents in vitro and in vivo. This review summarizes both the catabolic effects of GCs and the anabolic and metabolic effects of GH and IGF-I.
Both GH and IGF-I may decrease the catabolic effects of chronic steroid use in humans, particularly by enhancing lean body mass accrual and, in children, by increasing linear growth.