Relationship between the Inspiratory Capacity and Clinical Characters of Stable Chronic Obstructive Pulmonary Disease

Objective To explore the relationship between the inspiratory capacity(IC) and clinical characters of stable chronic obstructive pulmonary disease(COPD).Methods Between December 2009 and June 2010,84 patients with stable COPD were enrolled.Lung function(FEV1,IC,IC/TLC),6 minute walk-test(6MWT) and St George′s respiratory questionnaire(SGRQ) were examined.The relationship among FEV1,IC,IC/TLC,and the results of 6MWT and SGRQ by Pearson correlation analysis.Results There was no linear correlation between 6MWT and FEV1(r=0.14,P0.1),and 6MWT and FEV1≥60%(r=0.16,P0.1).There was positive correlation between 6MWT and IC(r=0.317,P0.01),and 6MWT and IC/TLC(r=0.274,P0.01).There was negative correlation between SGRQ and FEV1(r=-0.307,P0.01);and no linear correlation between SGRQ and IC(r=-0.001,P0.25),and SGRQ and IC/TLC(r=-0.003,P0.25).Conclusion In stable COPD patients,IC may be more accurate than FEV1 in refection of exercise tolerance while FEV1 may be more sensitive than IC in evaluation of dyspnea.