Effect of growth hormone on exercise tolerance in children with cystic fibrosis.
OBJECTIVE
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, .VO(2peak), 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 .VO(2peak) (+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 .VO(2peak) could be explained by those in LBM and FEV1 (P = 0.001).


CONCLUSIONS
GH treatment clearly improved exercise tolerance, presumably resulting from the combined effects of GH on the muscular, cardiovascular, and pulmonary capacity.
Hütler
Matthias
M
Sports Medicine, Free University Berlin, Clayallee 225C, 14195 Berlin, Germany. huetler@zedat.fu-berlin.de
Schnabel
Dirk
D
Staab
Doris
D
Tacke
Albrecht
A
Wahn
Ulrich
U
Böning
Dieter
D
Beneke
Ralph
R
D000293:Adolescent; D015992:Body Mass Index; D002648:Child; D018592:Cross-Over Studies; D003550:Cystic Fibrosis / Q000188:drug therapy* / Q000503:physiopathology*; D017079:Exercise Tolerance; D005260:Female; D019382:Human Growth Hormone / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D011994:Recombinant Proteins / Q000627:therapeutic use; D016896:Treatment Outcome
D011994:Recombinant Proteins; D019382:Human Growth Hormone