ObjectiveTo explore the difference in clinical characteristics and airway inflammation in COPD patients with different bronchodilator test results. MethodsA total of 237 COPD patients visited between January 2013 and December 2014 were recruited in the study. The ability to complete daily living questionnaire (ADL),modified Medicine Research Council (mMRC) score,6-minute walk distance,pulmonary function,and cell count in induced sputum were measured in the patients. They were divided into a positive group and a negative group according to the response to bronchodilator test and compared. ResultsThere were 58 cases (24.47%) in the positive group,and 179 cases (75.53%) in the negative group. There were no differences in the cumulative amount of smoking[(44.36±17.51) pack-years vs. (50.15±30.51) pack-years],duration of recurrent cough[(14.1±11.1) years vs. (15.5±11.4) years],history of allergic diseases (22.40% vs. 30.80%),or family history of allergic disease (5.17% vs. 2.23%) between two groups. In the positive group,FEV1%pred[(51.04±13.26)% vs. (44.10±14.66)%] and FVC%pred[(73.81±13.60)% vs. (64.33±15.17)%] were better than those of the negative group (both P<0.05). DLCO%pred[(44.66±13.92)% vs. (40.60±17.31)%] and RV/TLC[(51.80±10.57)% vs. (53.16±11.15)%] had no significant differences between two groups. 43.10% of the patients in the positive group and 61.46% in the negative group felt shortness of breath after walking (P<0.05). The positive group scored 22.6±3.8 points in activities of daily living assessment,1.5±0.9 points in mMRC,436.22±102.83 meters in 6-minute walking test,and 2.7±2.1 points in Borg scale score,which were all better than those in the negative group (all P<0.05). There was no significant difference in cell counting in induced sputum between two groups. ConclusionsA part of COPD patients have positive response to bronchodilator,with better lung function,better ADL score,better mMRC score,and farther 6-minute walking distance. It suggests that a positive bronchodilator response might be a clinical phenotype of COPD.