Neuromuscular electrical stimulation may benefit COPD patients
MedWire News: Results from a Canadian study suggest that neuromuscular electrical stimulation (NMES) may reduce muscle atrophy in patients with severe chronic obstructive pulmonary disease (COPD).
Muscle wasting is common in patients with severe COPD and has a significant negative impact on daily functioning, explained lead researcher Isabelle Vivodtzev (Laval University, Quebec) at the American Thoracic Society International Conference in New Orleans, Louisiana, USA.
She added that general physical reconditioning is currently used to improve limb muscle function in COPD patients, but many patients with severe disease are unable to perform the necessary amount of exercise due to dyspnea, or do not show the expected gain in functional status or muscle function.
To investigate whether NMES can reduce muscle wasting in such patients, Vivodtzev and team studied 20 patients with severe COPD who had an FEV1 of less than 50% of the predicted value and a 6-minute walking distance of less than 400 meters. Of these, 12 were assigned to receive home-based NMES and eight were assigned to receive a sham procedure for 30 minutes, 5 days a week over 6 weeks.
At the end of the study period, mean quadricep and calf cross-sectional areas had both increased by 6% in patients who received NMES compared with respective mean losses of 1% and 2% in those who received the sham procedure.
NMES was associated with a significant reduction in levels of the atrogin-1 protein, which is involved in muscle protein degradation, and maintenance of p70S6K protein levels, which is involved in muscle protein synthesis. In contrast, atrogin-1 protein levels did not change and p70S6K protein levels fell in patients assigned to receive the sham procedure.
"NMES improved quadriceps and calf muscle mass. Improvements in quadriceps muscle mass were positively correlated with changes in the level of proteins involved in muscle signaling pathway," commented Vivodtzev.
"These results suggested that NMES training would increase the anabolism to catabolism ratio in muscle proteins of COPD patients and prevent muscle-wasting."
She concluded: "Because it has little impact on ventilatory requirements and dyspnea, NMES appears as a promising alternative to general physical reconditioning in advanced COPD and its feasibility has been confirmed in this population."
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By Mark Cowen