Insulin-like growth factor-1 lowers protein oxidation in patients with thermal injury.
OBJECTIVE
The effect of insulin-like growth factor-1 (IGF-1) on energy expenditure and protein and glucose metabolism in a group of patients with thermal injury was determined.


BACKGROUND
Accelerated protein catabolism is a constant feature of the hypermetabolic response to thermal injury. Insulin-like growth factor-1 has been reported to minimize protein catabolism and normalize energy expenditure in animal models of thermal injury.


METHODS
To determine the efficacy of IGF-1 in human burn patients, resting energy expenditure (metabolic cart), whole body protein kinetics (N15 Lysine), and glucose disposal (glucose tolerance test) were assessed in eight burn patients before and after a 3-day infusion of IGF-1 (20 micrograms/kg/hr). All patients were fluid-resuscitated uneventfully and were without obvious infection at the time of study. Enteral nutrition was administered at a constant rate before and during the IGF-1 infusion.


RESULTS
Resting energy expenditure was not altered by IGF-1 (40.3 +/- 2.2 vs. 39.1 +/- 2.3 kcal/kg/day). However, glucose uptake was promoted, and protein oxidation decreased significantly (0.118 +/- 0.029 vs. 0.087 +/- 0.021 g/kg/d, p < 0.05) by IGF-1. In addition, insulin secretion, in response to a glucose challenge, was blunted.


CONCLUSIONS
Insulin-like growth factor-1 therapy has a beneficial effect in preserving lean body mass during severe stress conditions by minimizing the flux of amino acids toward oxidation.
Cioffi
W G
WG
U.S. Army Institute of Surgical Research, Fort Sam Houston, Texas.
Gore
D C
DC
Rue
L W
LW
Carrougher
G
G
Guler
H P
HP
McManus
W F
WF
Pruitt
B A
BA
D000328:Adult; D002056:Burns / Q000188:drug therapy / Q000378:metabolism*; D004734:Energy Metabolism / Q000187:drug effects*; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007262:Infusions, Intravenous; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology / Q000627:therapeutic use*; D008875:Middle Aged; D010084:Oxidation-Reduction; D011506:Proteins / Q000187:drug effects / Q000378:metabolism*
D011506:Proteins; D007334:Insulin-Like Growth Factor I; D005947:Glucose