Objectives: The aim of the study was to determine whether growth hormone (GH) treatment decreased net protein catabolism of lean tissues in patients receiving chronic glucocorticoid treatment.
Design: Whole body leucine kinetics were measured in post-absorptive conditions using a 1-14C-leucine infusion before and during GH administration (0.0125 mg/kg/day; 0.033 U/kg/day) for 7 days.
Patients: We studied four patients (age range 31-71 years) who had taken prednisone (mean +/- SEM 0.21 +/- 0.03 mg/kg/day, total dose 10-27.5 mg/day) for longer than 5 months for various lung diseases.
Results: During GH treatment leucine oxidation decreased (baseline 0.44 +/- 0.07 vs GH 0.37 +/- 0.05 mumol/kg lean body mass/min, P = 0.01) and non-oxidative leucine disposal increased (1.95 +/- 0.10 vs 2.05 +/- 0.09 mumol/kg lean body mass/min, P = 0.02) but leucine appearance was unaltered.
Conclusions: We conclude that GH decreased amino acid catabolism and improved protein synthesis without altering protein breakdown in patients receiving chronic glucocorticoid treatment. There may be a role for GH in mitigating the protein catabolic side-effects of prolonged glucocorticoid treatment.