TO THE EDITOR: The authors of the Viewpoint (2) propose that a cut-off point for initiation of hypoxia-induced muscle wasting is ~5,000 km·h. Although they employ a valuable new metric, incorporating elevation and total exposure time, we previously suggested that it might be better to quantify the hypoxic stimuli by using “saturation hours” (4). This is particularly important given that both (d...

Muscular dystrophies comprise a large group of inherited disorders that lead to progressive muscle wasting. We wanted to investigate if targeting satellite cells can enhance muscle regeneration and thus increase muscle mass. We treated mice with hepatocyte growth factor and leukemia inhibitory factor under three conditions: normoxia, hypoxia and during myostatin deficiency. We found that hepato...

Maintenance of skeletal muscle mass is regulated by the balance between anabolic and catabolic processes. Mammalian target of rapamycin (mTOR) is an evolutionarily conserved serine/threonine kinase, and is known to play vital roles in protein synthesis. Recent findings have continued to refine our understanding of the function of mTOR in maintaining skeletal muscle mass. mTOR controls the anabo...

Background Cachexia is a debilitating complication of cancer characterized by progressive wasting and weakness skeletal muscles that reduces quality life can compromise survival. Many anticancer treatments, such as chemotherapy, also cause muscle wasting, which impairs the response to treatment. Given many patients present with cachexia at initiation treatment, we investigated whether cachectic...

BACKGROUND Reduced growth is common in children with sickle cell anemia, but few data exist on associations with long-term clinical course. Our objective was to determine the prevalence of malnutrition at enrollment into a hospital-based cohort and whether poor nutritional status predicted morbidity and mortality within an urban cohort of Tanzanian sickle cell anemia patients. DESIGN AND METH...

1. Differing patterns of protein metabolism are seen in wasting due to undernutrition and wasting due to chronic infection. 2. We investigated whole body energy and protein metabolism in nine subjects with pulmonary tuberculosis, six undernourished subjects (body mass index < 18.5 kg/m2) and seven control subjects from an Indian population. Fasting subjects were infused with L-[1-13C]leucine (2...

Remels AH, Gosker HR, Langen RC, Schols AM. The mechanisms of cachexia underlying muscle dysfunction in COPD. J Appl Physiol 114: 1253–1262, 2013. First published September 27, 2012; doi:10.1152/japplphysiol.00790.2012.—Pulmonary cachexia is a prevalent, debilitating, and well-recognized feature of COPD associated with increased mortality and loss of peripheral and respiratory muscle function. ...