Bernard S, LeBlanc P, Whittom F, Carrier G, Jobin J, Belleau R, Maltais F
Unité de Recherche, Institut de Cardiologie et de Pneumologie de Québec, Université Laval, Ste-Foy, Québec, Canada.
Am J Respir Crit Care Med. 1998 Aug;158(2):629-34. doi: 10.1164/ajrccm.158.2.9711023.
Peripheral muscle weakness is commonly found in patients with chronic obstructive pulmonary disease (COPD) and may play a role in reducing exercise capacity. The purposes of this study were to evaluate, in patients with COPD: (1) the relationship between muscle strength and cross-sectional area (CSA), (2) the distribution of peripheral muscle weakness, and (3) the relationship between muscle strength and the severity of lung disease. Thirty-four patients with COPD and 16 normal subjects of similar age and body mass index were evaluated. Compared with normal subjects, the strength of three muscle groups (p < 0.05) and the right thigh muscle CSA, evaluated by computed tomography (83.4 +/- 16.4 versus 109.6 +/- 15.6 cm2, p < 0.0001), were reduced in COPD. The quadriceps strength/thigh muscle CSA ratio was similar for the two groups. The reduction in quadriceps strength was proportionally greater than that of the shoulder girdle muscles (p < 0.05). Similar observations were made whether or not patients had been exposed to systemic corticosteroids in the 6-mo period preceding the study, although there was a tendency for the quadriceps strength/thigh muscle CSA ratio to be lower in patients who had received corticosteroids. In COPD, quadriceps strength and muscle CSA correlated positively with the FEV1 expressed in percentage of predicted value (r = 0.55 and r = 0. 66, respectively, p < 0.0005). In summary, the strength/muscle cross-sectional area ratio was not different between the two groups, suggesting that weakness in COPD is due to muscle atrophy. In COPD, the distribution of peripheral muscle weakness and the correlation between quadriceps strength and the degree of airflow obstruction suggests that chronic inactivity and muscle deconditioning are important factors in the loss in muscle mass and strength.
外周肌肉无力在慢性阻塞性肺疾病（COPD）患者中很常见，可能在降低运动能力方面起作用。本研究的目的是评估COPD患者：（1）肌肉力量与横截面积（CSA）之间的关系，（2）外周肌肉无力的分布情况，以及（3）肌肉力量与肺部疾病严重程度之间的关系。对34例COPD患者和16例年龄及体重指数相似的正常受试者进行了评估。与正常受试者相比，COPD患者的三组肌肉力量（p<0.05）以及通过计算机断层扫描评估的右侧大腿肌肉CSA（83.4±16.4对109.6±15.6 cm²，p<0.0001）均降低。两组的股四头肌力量/大腿肌肉CSA比值相似。股四头肌力量的降低比例大于肩胛带肌肉（p<0.05）。无论患者在研究前6个月内是否接受过全身糖皮质激素治疗，均有类似观察结果，尽管接受糖皮质激素治疗的患者股四头肌力量/大腿肌肉CSA比值有降低趋势。在COPD患者中，股四头肌力量和肌肉CSA与预测值百分比表示的FEV1呈正相关（分别为r = 0.55和r = 0.66，p<0.0005）。总之，两组之间的力量/肌肉横截面积比值无差异，提示COPD患者的肌肉无力是由于肌肉萎缩所致。在COPD患者中，外周肌肉无力的分布以及股四头肌力量与气流阻塞程度之间的相关性表明，长期不活动和肌肉失健是肌肉质量和力量丧失的重要因素。
