Sovtic Aleksandar, Minic Predrag, Markovic-Sovtic Gordana, Trajkovic Goran Z
Department of Pulmonology, Mother and Child Health Institute of Serbia, Belgrade, Serbia.
School of Medicine, University of Belgrade, Belgrade, Serbia.
Front Pediatr. 2018 Sep 4;6:244. doi: 10.3389/fped.2018.00244. eCollection 2018.
Decreased respiratory muscle strength in patients with cystic fibrosis (CF) may cause progressive exercise intolerance during cardiopulmonary exercise testing (CPET), and may contribute to the development of chronic respiratory insufficiency. The aim of this study is to evaluate exercise tolerance during CPET of children and adults with clinically stable CF who exhibit different respiratory muscle strength. Sixty-nine clinically stable CF subjects aged 8-33 years underwent spirometry, body plethysmography, CPET, and respiratory muscle strength measurement. Respiratory muscle strength was measured using maximal inspiratory pressures (Pi) and maximal expiratory pressures (Pe). Participants were stratified into three groups according to Pi values:below normal (≤80% predicted), normal (81-100% predicted), and above normal (>100% predicted). A similar stratification of participants was made according to Pe values. The oxygen consumption on peak load (VO) was expressed relative to BM (VO/kg), relative to BM raised by the exponent of 0.67 (VO/kg) and as log-linear adjustment of VO (VO). Participants with low Pe values had a lower mean maximum load per kilogram/predicted (W; = 0.001) VO/kg ( = 0.006), VO/kg ( = 0.038) and VO ( = 0.001). There were no significant differences in exercise tolerance parameters with regard to Pi values. Stepwise multiple linear regressions confirmed that Pe ( = 24.88, β = 0.48, < 0.001) was the most powerful predictor of W. There were no statistically significant differences in age, lung function parameters, exacerbation score, or respiratory muscle strength according to gender. In subjects with clinically stable CF, expiratory muscle strength is associated with a decrease in exercise performance during CPET and can predict exercise intolerance. Increase in expiratory muscle strength by patient specific rehabilitation protocols would result in improvement of exercise tolerance.
囊性纤维化（CF）患者呼吸肌力量下降可能会在心肺运动试验（CPET）期间导致进行性运动不耐受，并可能促使慢性呼吸功能不全的发展。本研究的目的是评估临床稳定的CF儿童和成人在CPET期间的运动耐量，这些患者表现出不同的呼吸肌力量。69名年龄在8至33岁的临床稳定CF受试者接受了肺量计检查、体容积描记法、CPET和呼吸肌力量测量。使用最大吸气压力（Pi）和最大呼气压力（Pe）测量呼吸肌力量。参与者根据Pi值分为三组：低于正常（≤预测值的80%）、正常（预测值的81-100%）和高于正常（>预测值的100%）。根据Pe值对参与者进行了类似的分层。峰值负荷时的耗氧量（VO）相对于体重（VO/kg）、相对于体重的0.67指数增加量（VO/kg）以及作为VO的对数线性调整（VO）来表示。Pe值较低的参与者每千克/预测值的平均最大负荷（W； = 0.001）、VO/kg（ = 0.006）、VO/kg（ = 0.038）和VO（ = 0.001）较低。关于Pi值，运动耐量参数没有显著差异。逐步多元线性回归证实，Pe（ = 24.88，β = 0.48， < 0.001）是W的最有力预测指标。根据性别，在年龄、肺功能参数、加重评分或呼吸肌力量方面没有统计学上的显著差异。在临床稳定的CF受试者中，呼气肌力量与CPET期间运动表现的下降相关，并且可以预测运动不耐受。通过针对患者的康复方案增加呼气肌力量将导致运动耐量的改善。
