Severe burn injury elicits the release of catabolic hormones that contribute to negative nitrogen balance, protein wasting, and impaired wound healing. Previous studies have shown that burn patients receiving recombinant human growth hormone (rhGH) therapy have an increase in the rate of skin donor site healing and a shorter hospital stay. The mechanism by which rhGH exerts its effects, however, is not clearly understood. This study examines the effects of rhGH on circulating levels of catabolic hormones and nonesterified fatty acids in pediatric burn patients. Patients with greater than 40% total body surface area burn were randomly assigned to receive placebo (n = 8) or 0.2 mg/kg/day rhGH (n = 6) throughout their hospitalization. All patients had early morning blood samples assessed for catecholamines (CAT), cortisol, insulin, glucagon, and free fatty acid (FFA) levels during a period of hypermetabolism. No differences could be demonstrated in age, burn size, postburn day of evaluation, resting energy expenditure per kilogram, respiratory rate, heart rate, respiratory quotient, serum cortisol, and serum glucose between placebo- and rhGH-treated patients. The rhGH-treated group did show a significant elevation (p less than 0.05) in insulin-like growth factor-1 (55.9 +/- 14.5 vs. 168 +/- 23.7 mU/mL), total catecholamines (1,817 +/- 177 vs. 1,117 +/- 137 pg/mL), norepinephrine (1,257 +/- 121 vs. 867 +/- 113 pg/mL), epinephrine (385 +/- 175 vs. 147 +/- 36 pg/mL), insulin (32.8 +/- 3.3 vs. 25.0 +/- 3.0 mU/mL), glucagon (215 +/- 18 vs. 158 +/- 22 pg/mL), and free fatty acids (0.74 +/- 0.01 vs. 0.59 +/- 0.04 mEq/L) compared with the placebo group (data expressed as mean +/- SE).(ABSTRACT TRUNCATED AT 250 WORDS)