help button home button Endocrine Society JCEM
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
This version published online on June 23, 2009
Journal of Clinical Endocrinology & Metabolism , doi:10.1210/jc.2009-0407
This Article
Right arrow Author Manuscript (PDF)
Right arrow All Versions of this Article:
94/9/3265    most recent
Author Manuscript (PDF)
Right arrow Submit a related Letter to the Editor
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Copyright Permission
Google Scholar
Right arrow Articles by Goto, K.
Right arrow Articles by Kjaer, M.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Goto, K.
Right arrow Articles by Kjaer, M.
Related Collections
Right arrow Neuroendocrinology and Pituitary
Right arrow Pediatric Endocrinology
Right arrow Male Endocrinology

Submitted on February 23, 2009
Accepted on June 12, 2009

Growth Hormone Receptor Antagonist Treatment Reduces Exercise Performance in Young Males

Kazushige Goto*, Simon Doessing, Rie Harboe Nielsen, Allan Flyvbjerg, and Michael Kjaer

Institute of Sports Medicine, Bispebjerg Hospital, Copenhagen, Denmark; Faculty of Sport Sciences, Waseda University, Saitama, Japan; Medical Research Laboratories, Aarhus University Hospital, Aarhus, Denmark

* To whom correspondence should be addressed. E-mail: kgoto{at}aoni.waseda.jp.

Context: The effects of GH on exercise performance remain unclear.

Objective: To examine the effects of GH receptor (GHR) antagonist treatment on exercise performance.

Design: Subjects were treated with the GHR antagonist pegvisomant or placebo for 16 days. After the treatment period, they exercised to determine exercise performance, hormonal and metabolic responses.

Participants: 20 healthy males.

Intervention: Subjects were treated with the GHR antagonist (n=10, 10 mg/d) or placebo (n=10). After treatment period, they performed a maximal oxygen uptake (VO2max) test, and prolonged exercise test, consisting of 60 min submaximal cycling followed by exercise to fatigue at 90% of VO2max.

Main Outcome Measures: VO2max was measured before and after the treatment period. Hormonal and metabolic responses, and time to exhaustion during prolonged exercise were determined.

Results: Resting serum IGF-I concentration decreased by 20% in the GHR antagonist treated group (P < 0.05), whereas no change was observed in the placebo group. Conversely, resting serum GH concentration was significantly higher in the treatment group compared with the placebo group (P < 0.01). VO2max did not change significantly in either group after the treatment period. Time to exhaustion at 90% of VO2max was significantly shorter in the treatment group (P < 0.05). No significant differences were observed between the groups in terms of changes in serum free fatty acids, glycerol, VO2, or relative fat oxidation.

Conclusion: GH might be an important determinant of exercise capacity during prolonged exercise, but GHR antagonist did not alter fat metabolism during exercise.
Key words: pegvisomant • endurance exercise • fatigue






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Endocrinology Endocrine Reviews J. Clin. End. & Metab.
Molecular Endocrinology Recent Prog. Horm. Res. All Endocrine Journals
Copyright © 2009 by The Endocrine Society