PLASMA LEPTIN LEVELS IN TRAUMA PATIENTS - EFFECT OF ADJUVANT RECOMBINANT HUMAN GROWTH-HORMONE IN INTRAVENOUSLY FED MULTIPLE TRAUMA PATIENTS

Background: Leptin, the newly discovered ob gene product, is synthesiz ed primarily in adipose tissue and circulates to all parts of the body . Injury elicits significant metabolic changes, and it is not known ho w these changes affect the circulating leptin levels. Methods: Plasma leptin levels were measured in postabsorptive normal subjects (n = 14, 5 men and 9 women) and severely injured (injury severity score [ISS], 34 +/- 2), hypermetabolic (resting energy expenditure [REE]/basal ene rgy expenditure [BEE], 1.31 +/- 0.04), adult (39 +/- 4 years; n = 28, 18 men and 10 women) trauma patients within 48 to 60 hours after injur y when they were receiving no nitrogen or calories. The nutritional in fluence on plasma leptin in these patients was monitored during the su bsequent 7 days of total parenteral nutrition (TPN). During TPN the pa tients were randomized to receive or not to receive recombinant human growth hormone (rhGH) supplementation (0.15 mg/kg/d). Results: Trauma significantly lowered plasma leptin levels, both in women (56%) and in men (68%). Gender dimorphism in plasma leptin levels was seen in norm al subjects and in both fasted and fed trauma patients, and in all cas es female patients had significantly higher levels. Body mass index sh owed significantly positive correlations with plasma leptin both in no rmal and injured subjects. One day of TPN restored normal levels of le ptin, both in men and women. Adjuvant rhGH treatment did not show any significant changes over that seen with TPN alone. Conclusions: Decrea sed plasma leptin levels seen due to trauma may be partly related to t he fasting conditions, because 1 day of refeeding restored normalcy. L eptin metabolism in trauma patients seemed to be not altered during rh GH supplementation, suggesting a relatively minor metabolic role of le ptin.