THE ROLE OF IGFS IN CATABOLISM

The hypercatabolic response to trauma, extensive surgery and sepsis is characterized by an increased metabolic rate, severe muscle wasting a nd a negative nitrogen balance. This process of 'autocannibalism' may be in part a consequence of a disordered growth hormone (GH)/insulin-l ike growth factor (IGF) axis. In this chapter the normal physiology of the GH/IGF axis is first briefly reviewed. This is followed by a disc ussion of the changes that accompany fasting and catabolic illness, th e effects of IGF-1 administration in health and disease and a comparis on of the effects of IGF-1, GH and insulin on catabolism. Although ini tial investigations of IGF-1 administration in animals and human volun teers have often been encouraging, studies in catabolic patients have so far proved disappointing. Combined treatment with GH, IGF-1 (and in sulin) or with IGF-I and its major binding protein, may prove more eff ective, especially when used in conjunction with nutritional supplemen ts such as glutamine.