ANABOLIC EFFECT OF BIOSYNTHETIC GROWTH-HORMONE IN CYSTIC-FIBROSIS PATIENTS

The purpose of this study was to determine whether GH treatment of cys tic fibrosis (CF) patients can result in an anabolic effect, i.e., inc reased weight gain, improved growth rate, nitrogen retention, and impr oved pulmonary function. Nine prepubertal endocrinologically normal CF patients (3 girls, 6 boys; chronological age (CA) 5.5-9.8 years, and bone age (BA) 4.5-9.0 years), received recombinant human growth hormon e (rhGH) 0.3 mg/kg/week subcutaneously for a period of 12 months (N = 8) or 9 months (N = 1). Normal glucose tolerance was determined before treatment. Pulmonary function studies and anthropometric measurements were done every 3 months. Thyroid status, somatomedin C (SmC), BA, an d routine chemistries were evaluated every 6 months. The pretreatment growth velocity averaged 5.7 +/- 0.3 (SE) cm/year and significantly in creased to 7.8 +/- 0.4 (SE) cm/year during therapy, (P < 0.01). Standa rd deviation scores (SDS) for height significantly increased during rh GH therapy as compared with pretreatment, (P < 0.05). Weight of the pa tients during rhGH therapy did not significantly change during or afte r rhGH therapy. After therapy, all patients showed a significant incre ase in arm muscle area (AMA) and a significant decrement in arm fat ar ea (AFA) (P < 0.01). Net nitrogen anabolism was negative in all subjec ts before therapy but became more positive in five patients during rhG H therapy. Three patients acheived positive nitrogen retention. SmC va lues significantly increased from a mean value of 0.62 +/- 0.1 (SE) U/ ml to 1.6 +/- 0.6 (SE) U/ml after therapy. BA advanced 1.0 +/- 0.1 SE per year after treatment. Of the seven patients able to perform adequa te pulmonary function testing, improvement occurred in FVC, FEV(1.0), and PEFR in 5, 5, and 4 patients, respectively, but these changes did not reach statistical significance. We conclude that biosynthetic rhGH therapy had a significant anabolic effect in CF patients as shown by increased growth velocity, SmC values, increased protein and decreased fat stores, and a positive or less negative net nitrogen retention in five of the patients. (C) 1996 Wiley-Liss, Inc.