The effect of insulin-like growth factor I on postburn hypermetabolism.

These studies were undertaken to examine the effects of insulin-like growth factor I (IGF-I) on the hypermetabolic state that follows major thermal injury. Male Sprague-Dawley rats weighing 275 to 325 gm were subjected to a 50% total body surface area, full-thickness scald burn. At the time of injury, osmotic pumps were surgically implanted and used to deliver IGF-I, 1000 micrograms/day, or an equivalent volume of placebo solution by constant infusion of 5 microliters/hr for 14 days. Metabolic rates were studied with oxygen-consumption measurements performed on days 3, 7, 10, and 14 after injury. Animal weight measurements were also performed at the above intervals, with serum total IFG-I levels measured at death. Total serum IGF-I levels were decreased significantly 14 days after injury compared with uninjured animals (p less than 0.05). Treatment with IGF-I resulted in a significant decrease in oxygen consumption and a significant increase in body weight compared with burned animals and those treated with placebo 10 and 14 days after injury (p less than 0.05). These data suggest that IGF-I causes a significant change in the metabolic response that follows severe thermal injury and point to a possible role for IGF-I in the treatment of patients after severe thermal injury.