Short-term administration of supraphysiological recombinant human growth hormone HGH does not increase maximum endurance exercise capacity in healthy, active young men and women with normal HGH-insulin-like growth factor I axes.
Berggren A - J Clin Endocrinol Metab - 01-JUN-2005; 90(6): 3268-73
From NIH/NLM MEDLINE
NLM Citation ID:
15784718 (PubMed)
Full Source Title:
Journal of Clinical Endocrinology and Metabolism
Publication Type:
Clinical Trial; Journal Article; Randomized Controlled Trial
Language:
English
Author Affiliation:
Department of Clinical Physiology, Sahlgrenska University Hospital, SE-41345 Göteborg, Sweden.
Authors:
Berggren A; Ehrnborg C; Rosén T; Ellegård L; Bengtsson BA; Caidahl K
Abstract:
CONTEXT: Despite the fact that the use of HGH as a doping agent in sports is widespread, little is known about its short-term effects. OBJECTIVE: The objective was to study the effects of HGH on exercise capacity. DESIGN: A double-blind, placebo-controlled study was used, with a treatment period of 28 d. SETTING: Subjects from general community studied ambulatory at a university hospital. PARTICIPANTS: Thirty healthy active young normal volunteers (15 women and 15 men) were recruited by local announcement, and all completed the study. INTERVENTION: All subjects were randomized to receive a low HGH dose (0.033 mg/kg.d or 0.1 IU/kg.d), a high HGH dose (0.067 mg/kg.d or 0.2 IU/kg.d), or placebo. MAIN OUTCOME MEASURES: Power output and oxygen uptake on bicycle exercise were the main outcome measures. Results: We found no effect of the low or high dosages of HGH on maximum oxygen uptake during exercise (mean +/- se for placebo, 45.2 +/- 1.6 to 45.2 +/- 2.1 ml/kg.min; HGH low dose, 42.8 +/- 1.6 to 42.8 +/- 1.6 ml/kg.min; HGH high dose, 44.8 +/- 3.4 to 44.8 +/- 2.2 ml/kg.min; not significant by two-way ANOVA). Neither was there any effect on maximum achieved power output during exercise or on blood pressure, heart rate, or the electrocardiographic ST level at rest or during exercise. HGH significantly increased total body weight (P = 0.028), an effect predominantly ascribed to fluid retention (increased extracellular water volume), whereas muscle mass (as indicated by intracellular water volume) did not change. However, changes in the latter correlated to changes in physical performance, possibly due to different training efforts. CONCLUSION: Administration of supraphysiological recombinant human HGH during a period of 4 wk does not improve power output or oxygen uptake.
Major Subjects:
- Exercise / * physiology
- Human Growth Hormone / * pharmacology
- Insulin-Like Growth Factor I / * physiology
- Physical Endurance / drug effects / * physiology
Additional Subjects:
- Blood Pressure / drug effects
- Body Water / metabolism
- Carbon Dioxide / blood
- Comparative Study
- Double-Blind Method
- Female
- Humans
- Male
- Oxygen / blood
- Oxygen Consumption / drug effects
- Partial Pressure
- Placebos
- Reference Values
- Research Support, Non-U.S. Gov't
Chemical Compound Name:
(Placebos); 124-38-9(Carbon Dioxide); 12629-01-5(Human Growth Hormone); 67763-96-6(Insulin-Like Growth Factor I); 7782-44-7(Oxygen)