Impact of GH substitution on exercise capacity and muscle strength in GH-deficient adults: a meta-analysis of blinded, placebo-controlled trials.
BACKGROUND
Several but not all trials suggest that GH replacement in GH-deficient adults improves aerobic exercise capacity, whereas its effect on muscle strength is more dubious. However, a denominator of these studies is a low sample size.


OBJECTIVE
We systematically reviewed and analysed all randomized, double-blind, placebo-controlled trials on the effects of GH administration on aerobic exercise capacity and muscle strength in GH-deficient adults.


METHODS
Fifteen trials were identified from four databases. We conducted an analysis of effects on aerobic exercise capacity, performed on either a treadmill or a bicycle ergometer, muscle strength assessed by a dynamometer, and muscle mass assessed by computerized tomography.


RESULTS
The total number of patients included was 306 and the duration of treatment ranged from 3 to 12 months. GH replacement significantly increased aerobic exercise capacity [8.9 ± 0.8%, (P < 0.001)] including VO(2) max [0.17 ± 0.02 l/min (P < 0.001)], as well as muscle volume [7.1 ± 1.6%, (P < 0.001)]. In contrast, muscle strength measured in 113 patients was not significantly increased [3.2 ± 2.2% (P = 0.15)].


CONCLUSIONS
GH replacement in GH-deficient adults is associated with a significant positive effect on aerobic exercise capacity and muscle mass.
Rubeck
K Z
KZ
Medical Department M and C, Aarhus University Hospital, Aarhus Sygehus, Aarhus, Denmark. kristine.rubeck@studmed
Bertelsen
S
S
Vestergaard
P
P
Jørgensen
J O L
JO
D000328:Adult; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D017079:Exercise Tolerance / Q000187:drug effects*; D019382:Human Growth Hormone / Q000008:administration & dosage / Q000172:deficiency / Q000627:therapeutic use*; D006801:Humans; D053580:Muscle Strength / Q000187:drug effects*; D010919:Placebos; D016032:Randomized Controlled Trials as Topic; D055815:Young Adult
D010919:Placebos; D019382:Human Growth Hormone