肺活量与用力肺活量差值预测慢性阻塞性肺疾病患者运动能力的研究

Difference between slow and forced vital capacity predicts exercise capacity in patients with chronic obstructive pulmonary disease

目的:探讨慢性阻塞性疾病(chronic obstructive pulmonary disease,COPD)患者慢肺活量(vital capacity,VC)与用力肺活量(forced vital capacity,FVC)的差值(VC-FVC)与运动能力的关系。方法:共97例COPD患者完成了常规肺功能和心肺运动试验,根据VC-FVC的结果分为两组:1组VC>FVC 77例,另1组VC≤FVC 20例,比较这两组的运动反应。结果:VC>FVC组的第1秒用力肺活量(FEV1)和最大摄氧量(peak VO2)均显著低于VC≤FVC组,VC-FVC与peak VO2有显著的负相关(r=-0.404,P<0.001),FEV1占预计值百分比(FEV1%)与peak VO2有显著的正相关(r=0.418,P<0.001),以peak VO2作为因变量进行多元逐步回归分析显示,VC-FVC、FEV1%和年龄与peak VO2相关,可解释peak VO235.9%的变化。结论:VC和FVC测定简单,其差值不仅可以反应COPD患者气体受限的程度,还可预测其运动能力。

Objective：A higher slow vital capacity （VC） compared with forced vital capacity （FVC） indicates small airway collapse and air trapping,whether a larger difference between VC and FVC （VC-FVC） could predict impaired exercise capacity in patients with chronic obstructive pulmonary disease （COPD） was investigated.Methods：Pulmonary function and incremental cardiopulmonary exercise responses were assessed in 97 COPD patients.Patients were then divided into two groups：one in which VC ＞ FVC （n =77） and the other in which VC ≤ FVC （n =20）.Results：Patients with VC ＞ FVC had lower FEV1 and peak oxygen uptake （VO2） compared with patients with VC ≤ FVC.There was a significant inverse correlation between VC-FVC and peak VO2/kg （r =-0.404,P ＜ 0.001）.There was also a direct correlation between FEV1 ％ pred and peak VO2/kg （r =0.418,P ＜ 0.001）.The results of the multivariate regression analysis with peak VO2 as the dependent variable showed that VC-FVC,FEV1 ％ pred and age were all significant independent predictors of peak VO2/kg,which may explain 35.9％ of the peak VO2/kg variance.Conclusion：The difference between VC and FVC is easily measured by spirometry,which can be used not only as an index of severity of airflow limitation,but also predict exercise capacity in COPD patients.