The GH/IGF-1 system in critical illness

► The GH and IGF-1 axis plays a pivotal role in critical illness. ► IGF-1 modulates hepatic acute phase response signal pathway. ► IGF-1 serum levels increase during critical illness and protease activity decreases. ► GH ameliorates hypermetabolism and catabolism, but mortality increase is associated. ► With adequate nutrition, anabolic therapy may still be appropriate in select groups.