Universität zu Köln

McDonnell, Adam C., Eiken, Ola, Frings-Meuthen, Petra, Rittweger, Joern and Mekjavic, Igor B. (2019). The LunHab project: Muscle and bone alterations in male participants following a 10 day lunar habitat simulation. Exp. Physiol., 104 (8). S. 1250 - 1262. HOBOKEN: WILEY. ISSN 1469-445X

Full text not available from this repository.

Abstract

New Findings What is the central question of this study?It is well established that muscle and bone atrophy in conditions of inactivity or unloading, but there is little information regarding the effect of a hypoxic environment on the time course of these deconditioning physiological systems. What is the main finding and its importance?The main finding is that a horizontal 10 day bed rest in normoxia results in typical muscle atrophy, which is not aggravated by hypoxia. Changes in bone mineral content or in metabolism were not detected after either normoxic or hypoxic bed rest. Musculoskeletal atrophy constitutes a typical adaptation to inactivity and unloading of weightbearing bones. The reduced-gravity environment in future Moon and Mars habitats is likely to be hypobaric hypoxic, and there is an urgent need to understand the effect of hypoxia on the process of inactivity-induced musculoskeletal atrophy. This was the principal aim of the present study. Eleven males participated in three 10 day interventions: (i) hypoxic ambulatory confinement; (ii) hypoxic bed rest; and (iii) normoxic bed rest. Before and after the interventions, the muscle strength (isometric maximal voluntary contraction), mass (lean mass, by dual-energy X-ray absorptiometry), cross-sectional area and total bone mineral content (determined with peripheral quantitative computed tomography) of the participants were measured. Blood and urine samples were collected before and on the 1st, 4th and 10th day of the intervention and analysed for biomarkers of bone resorption and formation. There was a significant reduction in thigh and lower leg muscle mass and volume after both normoxic and hypoxic bed rests. Muscle strength loss was proportionately greater than the loss in muscle mass for both thigh and lower leg. There was no indication of bone loss. Furthermore, the biomarkers of resorption and formation were not affected by any of the interventions. There was no significant effect of hypoxia on the musculoskeletal variables. Short-term normoxic (10 day) bed rest resulted in muscular deconditioning, but not in the loss of bone mineral content or changes in bone metabolism. Hypoxia did not modify these results.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code McDonnell, Adam C. UNSPECIFIED UNSPECIFIED UNSPECIFIED Eiken, Ola UNSPECIFIED UNSPECIFIED UNSPECIFIED Frings-Meuthen, Petra UNSPECIFIED UNSPECIFIED UNSPECIFIED Rittweger, Joern UNSPECIFIED UNSPECIFIED UNSPECIFIED Mekjavic, Igor B. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-145944
DOI:	10.1113/EP087482
Journal or Publication Title:	Exp. Physiol.
Volume:	104
Number:	8
Page Range:	S. 1250 - 1262
Date:	2019
Publisher:	WILEY
Place of Publication:	HOBOKEN
ISSN:	1469-445X
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language 10-DAY HYPOXIC CONFINEMENT; BED REST; SPACE-FLIGHT; SKELETAL-MUSCLE; BODY-COMPOSITION; NUTRITIONAL-STATUS; IN-VIVO; EXERCISE; ENERGY; METABOLISM Multiple languages Physiology Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/14594