Tanguay Sophie, Saey Didier, Marklund Sarah, Nyberg Andre, Gephine Sarah, Frykholm Erik, De Brandt Jana, Burtin Chris, Maltais François
Centre de Recherche, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec City, QC, Canada.
Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Section of Physiotherapy, Umeå, Sweden.
ERJ Open Res. 2023 Aug 29;9(4). doi: 10.1183/23120541.00313-2023. eCollection 2023 Jul.
The lack of reference values of lower-limb muscle function hinders the clinical recommendations of its measurement in patients with COPD. Therefore, this study aimed to develop reference equations to predict reference values for quadriceps strength, endurance and power and evaluate their construct validity in patients with COPD.
Quadriceps strength, endurance and power were assessed in 158 healthy individuals and 87 patients with COPD. In addition, patients with COPD performed a 6-min walk test (6MWT) and a 1-min sit-to-stand test (1STS). Multiple linear regressions were performed to develop reference equations. The proportion of patients with COPD with reduced quadriceps function was determined, and correlations between quadriceps strength, endurance and power expressed in percentage of predicted values and 6MWT and 1STS performance were used to document the construct validity of the reference equation.
Except for quadriceps isometric endurance, the proposed reference equations explained 50-70% of the variance of the quadriceps properties in healthy individuals. All quadriceps properties were systematically reduced in a large proportion of patients with COPD compared to healthy individuals. Correlation coefficients between quadriceps properties expressed in percentage of predicted values and 6MWT and 1STS performance ranged between 0.28 and 0.49 (all p<0.05).
In healthy individuals, age, sex, height and body mass index explained 50-70% of the variance of quadriceps strength, endurance and power. When expressed in percentage of predicted values, these quadriceps properties correlated with 6MWT and 1STS performance, suggesting construct validity of the reference values in patients with COPD.
下肢肌肉功能缺乏参考值阻碍了慢性阻塞性肺疾病（COPD）患者中其测量的临床推荐。因此，本研究旨在制定参考方程以预测股四头肌力量、耐力和功率的参考值，并评估其在COPD患者中的结构效度。
对158名健康个体和87名COPD患者进行股四头肌力量、耐力和功率评估。此外，COPD患者进行了6分钟步行试验（6MWT）和1分钟坐立试验（1STS）。进行多元线性回归以制定参考方程。确定股四头肌功能降低的COPD患者比例，并使用以预测值百分比表示的股四头肌力量、耐力和功率与6MWT和1STS表现之间的相关性来记录参考方程的结构效度。
除股四头肌等长耐力外，所提出的参考方程解释了健康个体中股四头肌特性方差的50 - 70%。与健康个体相比，大部分COPD患者的所有股四头肌特性均系统性降低。以预测值百分比表示的股四头肌特性与6MWT和1STS表现之间的相关系数在0.28至0.49之间（所有p<0.05）。
在健康个体中，年龄、性别、身高和体重指数解释了股四头肌力量、耐力和功率方差的50 - 70%。当以预测值百分比表示时，这些股四头肌特性与6MWT和1STS表现相关，表明这些参考值在COPD患者中的结构效度。
