Ciavaglia Casey E, Guenette Jordan A, Langer Daniel, Webb Katherine A, Alberto Neder J, O'Donnell Denis E
Respiratory Investigation Unit, Department of Medicine, Queen's University & Kingston General Hospital, Kingston, Ontario, Canada;
Respiratory Investigation Unit, Department of Medicine, Queen's University & Kingston General Hospital, Kingston, Ontario, Canada; Department of Physical Therapy and UBC Centre for Heart Lung Innovation, University of British Columbia, Vancouver, British Columbia, Canada; and.
J Appl Physiol (1985). 2014 Dec 1;117(11):1292-301. doi: 10.1152/japplphysiol.00502.2014. Epub 2014 Oct 9.
In patients with combined obesity and chronic obstructive pulmonary disease (COPD), dyspnea intensity at matched work rates during weight-supported cycling and weight-bearing walking is similar, despite consistent metabolic differences between test modalities. The present study examined the influence of differences in activity of the diaphragm and abdominal muscles during cycling and walking on intensity and quality of dyspnea at matched ventilation in obese patients with COPD. We compared respiratory muscle activity patterns and dyspnea ratings during incremental cycle and treadmill exercise tests, where work rate was matched, in 12 obese (body mass index 36.6 ± 5.4 kg/m(2); mean ± SD) patients with moderate COPD. We used a multipair electrode-balloon catheter to compare electromyography of the diaphragm and esophageal, gastric, and transdiaphragmatic pressures during the two exercise tests. Ventilation, breathing pattern, operating lung volumes, global respiratory effort, and electrical activation of the diaphragm were similar across exercise modalities for a given work rate. The cycling position was associated with greater neuromuscular efficiency of the diaphragm (P < 0.01), greater diaphragm use (P < 0.01) measured by the ventilatory muscle recruitment index, and less expiratory muscle activity compared (P < 0.01) with treadmill walking. However, intensity and quality of dyspnea were similar between exercise modalities. In obese patients with COPD, altered respiratory muscle activity due to body position differences between cycling and walking did not modulate perceived dyspnea when indirect measures of respiratory neural drive were unchanged.
在合并肥胖和慢性阻塞性肺疾病（COPD）的患者中，尽管体重支持骑行和负重行走这两种测试方式在代谢方面存在持续差异，但在匹配的工作负荷下，呼吸困难强度相似。本研究探讨了肥胖COPD患者在骑行和行走过程中膈肌和腹肌活动差异对匹配通气时呼吸困难强度和性质的影响。我们比较了12例中度COPD肥胖患者（体重指数36.6±5.4kg/m²；均值±标准差）在递增式骑行和跑步机运动测试中的呼吸肌活动模式和呼吸困难评分，这两种测试的工作负荷是匹配的。我们使用多对电极-球囊导管比较了两种运动测试过程中膈肌的肌电图以及食管、胃和跨膈压。对于给定的工作负荷，不同运动方式下的通气、呼吸模式、工作肺容积、整体呼吸努力和膈肌的电激活情况相似。与跑步机行走相比，骑行姿势与更高的膈肌神经肌肉效率（P<0.01）、通过通气肌募集指数测量的更高的膈肌使用率（P<0.01）以及更低的呼气肌活动相关（P<0.01）。然而，不同运动方式下呼吸困难的强度和性质相似。在肥胖COPD患者中，当呼吸神经驱动的间接测量指标不变时，由于骑行和行走时身体姿势差异导致的呼吸肌活动改变并未调节所感知的呼吸困难。
