Effect of growth hormone on exercise tolerance in children with cystic fibrosis


Medicine & Science in Sports & Exercise:
CLINICAL SCIENCES: Clinical Investigations

HÜTLER, M., D. SCHNABEL, D. STAAB, A. TACKE, U. WAHN, D. BÖNING, and R. BENEKE. Effect of growth hormone on exercise tolerance in children with cystic fibrosis. Med. Sci. Sports Exerc., Vol. 34, No. 4, pp. 567–572, 2002.

Purpose: The effect of growth hormone (GH) treatment on exercise tolerance in children with cystic fibrosis was investigated.

Methods: 10 prepubertal children (mean ± SD; age: 12.1 ± 1.7 yr; height: 137.4 ± 9.2 cm; body mass: 27.8 ± 4.2 kg; forced expiratory volume in 1 s (FEV1): 68 ± 22% predicted) were randomly assigned to either control period (CON, standard therapy) or recombinant human growth hormone (GH) period (additional GH treatment, 0.11-0.14 IU·kg−1, daily, s.c.) for the first 6 months, and then assigned to the other period for the next 6 months. At study entry and after each period, anthropometric data, pulmonary function, and exercise capacity (peak exercise capacity, V̇O2peak, and isokinetic muscle strength) were measured.

Results: Changes in height (+4.3 ± 1.0 cm), total body mass (+2.2 ± 0.8 kg), and lean body mass (LBM, +2.9 ± 0.7 kg) were significantly higher (P < 0.01) after GH treatment compared with CON. Pulmonary function did not significantly change in either of the periods. In contrast to CON, GH treatment improved absolute V̇O2peak (+19%, P < 0.01), peak ventilation (+14%, P < 0.01), and peak oxygen pulse (+18%, P < 0.01). Analysis of variance revealed that most of the changes (71%) in V̇O2peak could be explained by those in LBM and FEV1 (P = 0.001).

Conclusion: GH treatment clearly improved exercise tolerance, presumably resulting from the combined effects of GH on the muscular, cardiovascular, and pulmonary capacity.

Author Information

Sports Medicine, Free University Berlin, Berlin, GERMANY; Children’s Hospital, Campus Virchow, Humboldt University, Berlin, GERMANY; and 1. Children’s Hospital Clinic Buch, GERMANY

Submitted for publication March 2001.

Accepted for publication August 2001.

©2002The American College of Sports Medicine