Division of Respirology, Department of Medicine, McMaster University, Hamilton, ON, Canada.
Firestone Institute for Respiratory Health, St Joseph's Healthcare, Hamilton, ON, Canada.
Physiol Rep. 2020 Apr;8(8):e14415. doi: 10.14814/phy2.14415.
The effort required to cycle and breathe intensify as power increases during incremental exercise. It is currently unclear how changes in FEV in the presence or absence of airflow limitation) impacts the intensity of dyspnea and leg effort. This is clinically important as the improvement in FEV is often the target for improving dyspnea.
To investigate the relationship between dyspnea (D), leg effort, power (P), and FEV with and without airflow limitation using direct psychophysical scaling performed during incremental exercise testing to symptom limited capacity.
Retrospective analysis of consecutive patients over the age of 35 referred for cardio-pulmonary exercise testing at McMaster University Medical Centre from 1988-2012.The modified Borg scale was used to measure dyspnea throughout incremental exercise testing.
38,788 patients were included in the analysis [Mean Age 58.6 years (SD ±11.8), Males 61%, BMI 28.1 kg/m (SD ±5.1), FEV was 2.7 L (SD ±0.85), 95% predicted (SD ±20.4), FVC 3.4 L (SD ± 1.0), 94% predicted (SD ±17.0)], and 10.9% had airflow limitation (AL, FEV /FVC < 70%). In a nonlinear regression analysis, the intensity of dyspnea increased in a positively accelerating manner with power and as the FEV % predicted decreased: Dyspnea = 0.06 * Power * FEV %Pred (r = .63). The intensity of leg effort increased with power and declining quadricep strength and FEV1% predicted: Leg Effort = 0.06 * Power * Quad *FEV %Pred (r = .73). There was no independent effect of AL on dyspnea of leg effort.
Power, quadriceps strength and FEV1 are the dominant factors contributing to dyspnea and leg effort, irrespective of the degree of airflow limitation.
在递增运动过程中，随着功率的增加，骑行和呼吸所需的努力也会增加。目前尚不清楚在存在或不存在气流受限的情况下，FEV 的变化如何影响呼吸困难和腿部用力的强度。这在临床上很重要，因为改善 FEV 通常是改善呼吸困难的目标。
使用递增运动测试至症状限制能力时直接进行心理物理标度来研究在存在或不存在气流受限的情况下，呼吸困难 (D)、腿部用力、功率 (P) 和 FEV 之间的关系。
对 1988 年至 2012 年期间在麦克马斯特大学医学中心进行心肺运动测试的年龄在 35 岁以上的连续患者进行回顾性分析。整个递增运动测试过程中使用改良的 Borg 量表来测量呼吸困难。
38788 例患者纳入分析[平均年龄 58.6 岁（SD ±11.8），男性 61%，BMI 28.1kg/m（SD ±5.1），FEV 为 2.7L（SD ±0.85），95%预计值（SD ±20.4），FVC 为 3.4L（SD ±1.0），94%预计值（SD ±17.0）]，10.9%存在气流受限（AL，FEV/FVC<70%）。在非线性回归分析中，呼吸困难的强度以正加速的方式随功率增加而增加，随着 FEV 预计值的降低而增加：呼吸困难=0.06功率FEV 预计值（r=.63）。腿部用力的强度随功率增加而增加，随着股四头肌力量和 FEV1 预计值的下降而增加：腿部用力=0.06功率股四头肌*FEV 预计值（r=.73）。AL 对呼吸困难和腿部用力没有独立影响。
功率、股四头肌力量和 FEV1 是导致呼吸困难和腿部用力的主要因素，与气流受限的程度无关。
