Purpose: Chronic exposure to hypoxia can induce muscle wasting in unaccustomed individuals. Detailed assessment of the effects of hypoxia on muscle tissue adaptation in elite mountaineers has not been performed. This study aims to assess muscle volume after exposure to normobaric hypoxia.
Methods: Two professional mountaineers (A and B) participated in a 35-d intervention of graded normobaric hypoxia with the aim of 14 d exposure to 8% oxygen corresponding to 7112-m altitude. Volume of the shank, thigh, and hip muscles was assessed by magnetic resonance imaging pre- and postintervention. Dietary intake and physical activity were monitored throughout the study from food images and accelerometry analysis, together with blood analysis and anthropometric measurements.
Results: Hypoxia reduced total leg muscle volume by 3.3% ± 6.0% in A and by 9.4% ± 7.3% in B. A lost 288 g and B 642 g of muscle mass, whereas dietary intake only declined by ~23% in the last intervention week. Arterial oxygen saturation declined from 95% and 86% to 77% and 72% in A and B, respectively. In hypoxia, participants could not maintain their physical activity levels. Notably, muscle loss varied substantially across muscle groups amounting to 5.4% ± 3.0%, 8.3% ± 5.2%, and 4.1% ± 8.6% for hip, thigh, and shank muscles, respectively.
Conclusions: Our results indicate that hypoxia and resultant reductions in physical activity and caloric intake lead to substantial loss of muscle mass that was accentuated in proximal muscle as opposed to distal muscles. Surprisingly, thigh muscle wasting during this intervention is comparable with that observed during strict 56-d bed rest.
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http://dx.doi.org/10.1249/MSS.0000000000003060 | DOI Listing |
Zhongguo Zhen Jiu
January 2025
College of TCM, Chongqing Medical University, Chongqing Key Laboratory of TCM for Prevention and Treatment of Metabolic Diseases, Chongqing 410007, China.
Objective: To assess the impacts of electroacupuncture (EA) on the gait, oxidative stress, inflammatory reaction, and protein degradation in the rats of denervated skeletal muscle atrophy, and explore the potential mechanism of EA for alleviating denervated skeletal muscle atrophy.
Methods: Forty male SD rats, 8 weeks old, were randomly assigned to a sham-surgery group, a model group, an EA group, and a p38 MAPK inhibitor group, with 10 rats in each group. The right sciatic nerve was transected to establish a rat model of denervated skeletal muscle atrophy in the model group, the EA group and the p38 MAPK inhibitor group.
Int J Chron Obstruct Pulmon Dis
January 2025
Pulmonology Department, Erciyes University Faculty of Medicine, Kayseri, Türkiye.
Background/aim: Chronic obstructive pulmonary disease (COPD) is often complicated by sarcopenia, a condition of reduced muscle mass and function that adversely affects quality of life, lung function, and exacerbation rates. Ultrasonography could be an effective tool for detecting sarcopenia, notably by assessing diaphragmatic function, which may indicate muscle health in COPD patients. This study aims to evaluate the effectiveness of diaphragmatic ultrasound in detecting sarcopenia among COPD patients.
View Article and Find Full Text PDFJBJS Essent Surg Tech
January 2025
The Ohio State University College of Medicine, Columbus, Ohio.
Background: An all-inside endoscopic flexor hallucis longus (FHL) tendon transfer is indicated for the treatment of chronic, full-thickness Achilles tendon defects. The aim of this procedure is to restore function of the gastrocnemius-soleus complex while avoiding the wound complications associated with open procedures.
Description: This procedure can be performed through 2 endoscopic portals, a posteromedial portal (the working portal) and a posterolateral portal (the visualization portal).
Age Ageing
January 2025
School of Nursing, Jilin University, Changchun, China.
Background: Age-related changes in body composition such as muscle loss can lead to sarcopenia, which is closely associated with frailty. However, the effect of body fat accumulation on frailty in old age remains unclear. In particular, the association between the combination of these two conditions, known as sarcopenic obesity, and frailty in older adults is unclear.
View Article and Find Full Text PDFJ Neurol
January 2025
Department of Neurology, University Hospital Basel, University of Basel, Basel, Switzerland.
Background: With the approval of disease-modifying treatments for 5q-spinal muscular atrophy (SMA), there is an increasing need for biomarkers for disease course and therapeutic response monitoring. Radially sampled Averaged Magnetization Inversion Recovery Acquisitions (rAMIRA) MR-imaging enables spinal cord (SC) gray matter (GM) delineation and quantification in vivo. This study aims to assess SC GM atrophy in patients with 5q-SMA and its associations with clinical disability.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!