Ju Chunrong, Liu Wei, Chen Rong-Chang
State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China.
Respir Care. 2014 Jul;59(7):1062-70. doi: 10.4187/respcare.02553. Epub 2013 Oct 15.
Patients with COPD have impaired respiratory muscle strength. Twitch mouth pressure (Ptw,m) in response to magnetic stimulation of the cervical nerve has been suggested to clinically reflect inspiratory muscle strength. However, studies on Ptw,m values and their relationship with disease severity are limited. Thus, we tested the Ptw,m values of subjects with COPD and investigated the relationship of these values with disease severity.
We recruited 75 COPD patients and 63 age-matched controls. All participants were tested for Ptw,m, sniff nasal pressure (SNIP), and maximum static inspiratory mouth pressure (PImax ); the BODE (body mass index, air flow obstruction, dyspnea, exercise capacity) index was evaluated for overall severity assessment and the 6-min walk distance (6MWD) was used to determine the exercise capacity of subjects with COPD.
Subjects with COPD had markedly lower Ptw,m values compared with the controls (10.00 ± 2.17 vs 13.66 ± 2.20 cm H2O for males, 8.83 ± 0.89 vs 11.81 ± 1.98 cm H2O for female; each with P < .001). The Ptw,m values decreased with increasing COPD severity, and similar trends were observed in the SNIP and PImax values. Regression correlation analysis showed that Ptw,m values were significantly correlated inversely with the BODE index (R = 0.65, P < .001) but positively correlated with 6MWD (R = 0.59, P < .001) in the COPD group; the SNIP values of subjects with COPD were also correlated inversely with their BODE index (R = 0.49, P < .001) but positively correlated with their 6MWD (R = 0.33, P < .005).
Ptw,m values are 26.8% lower in male subjects with COPD and 25.3% lower in female subjects with COPD compared with the controls. The Ptw,m values of subjects with COPD decrease with increasing disease severity. Ptw,m was better correlated with the BODE index and exercise capacity than SNIP and PImax , which suggests that Ptw,m more accurately reflects the overall severity and burden of COPD.
慢性阻塞性肺疾病（COPD）患者的呼吸肌力量受损。有人提出，对颈神经进行磁刺激时的抽搐口压（Ptw,m）在临床上可反映吸气肌力量。然而，关于Ptw,m值及其与疾病严重程度关系的研究有限。因此，我们测试了COPD患者的Ptw,m值，并研究了这些值与疾病严重程度的关系。
我们招募了75名COPD患者和63名年龄匹配的对照者。所有参与者均接受了Ptw,m、嗅鼻压（SNIP）和最大静态吸气口压（PImax）测试；评估了BODE（体重指数、气流阻塞、呼吸困难、运动能力）指数以进行整体严重程度评估，并使用6分钟步行距离（6MWD）来确定COPD患者的运动能力。
与对照组相比，COPD患者的Ptw,m值明显更低（男性分别为10.00±2.17 vs 13.66±2.20 cmH₂O，女性分别为8.83±0.89 vs 11.81±1.98 cmH₂O；P均<.001）。Ptw,m值随COPD严重程度增加而降低，SNIP和PImax值也观察到类似趋势。回归相关分析显示，在COPD组中，Ptw,m值与BODE指数呈显著负相关（R = 0.65，P <.001），但与6MWD呈正相关（R = 0.59，P <.001）；COPD患者的SNIP值也与其BODE指数呈负相关（R = 0.49，P <.001），但与6MWD呈正相关（R = 0.33，P <.005）。
与对照组相比，男性COPD患者的Ptw,m值低26.8%，女性COPD患者的Ptw,m值低25.3%。COPD患者的Ptw,m值随疾病严重程度增加而降低。与SNIP和PImax相比，Ptw,m与BODE指数和运动能力的相关性更好，这表明Ptw,m能更准确地反映COPD的整体严重程度和负担。
