Analysis Of Lung Function Characteristics And Inflammatory Mediators In Patients With Chronic Obstructive Pulmonary Disease With Different Bronchodilator Responsiveness

Objective: To compare the clinical features,lung function characteristics and expression levels of inflammatory mediators in patients with chronic obstructive pulmonary disease(COPD)with different volume diastolic responsiveness and different flow diastolic responsiveness.To explore the clinical significance of different bronchodilator responsiveness in patients with COPD.Methods: A total of 128 COPD patients in the respiratory department of the Second Hospital of Hebei Medical University admitted from January 2022 to December 2022 were collected.According to whether these patients meet the positive criteria of flow responses(FEV1-BDR),we divided them into FEV1-BDR positive group and FEV1-BDR negative group.According to whether these patients meet the positive criteria of volume responses(FVC-BDR),we divided them into FVC-BDR positive group and FVC-BDR negative group.To compare the clinical features,lung function indexes and expression levels of IL-4 and IFN-γ of FEV1-BDR-positive group and FEV1-BDR-negative group,FVC-BDR-positive group and FVC-BDR-negative group,respectively.Results:1.After inhalation of bronchodilators,FEV1 increased from(1.10±0.42)L to(1.26±0.48)L on average,FVC increased from(2.43±0.69)L to(2.73±0.75)L on average in COPD patients,and the difference was statistically significant(P<0.01).The mean difference of FVC change(296 ml)was significantly higher than that of FEV1 change(155 ml)(P<0.01).The FEV1 change rate was 13.9%,the FVC change rate was 15.2%,and there were no statistically differences in the change rates(P>0.05).The FEV1-BDR positivity rate was 35.2%(45/128),the FVC-BDR positivity rate was 48.4%(62/128).2.After inhalation of bronchodilators,the improvement of FEV1 and FVC were significantly different.As the GOLD stage was more severe,the improvement of FEV1 and FEV1-BDR positivity rate gradually decreased,but the improvement of FVC and FVC-BDR positivity rate gradually increased.In patients of the same severe GOLD stage,the improvement of FVC were significantly higher than FEV1.3.Compared with the FVC-BDR-negative group,m MRC grades were higher,number of exacerbations in the past year were more,FEV1,FEV1%pred before inhalation of bronchodilator were worse,DLCO%pred was lower,RV/TLC%pred was higher,Fe NO and IFN-γ were higher in the FVC-BDRpositive group(P<0.05).There were no significant differences in MMEF%pred,MEF25%pred,MEF50%pred,R5%pred,R20%pred,X5,and IL-4 between the FVC-BDR-positive group and the FVC-BDR-negative group(P>0.05).4.There were no significant differences between age,sex,BMI,smoking index,allergy,m MRC,number of exacerbations in the past year,MMEF%pred,MEF25%pred,MEF50%pred,DLCO%pred,RV/TLC%pred,R5%pred,R20%pred,X5,Fe NO,IL-4 and IFN-γ between the FEV1-BDR-positive group and the FEV1-BDR-negative group(P>0.05).Compared with the FEV1-BDRpositive group,FEV1,FVC before inhalation of bronchodilators were lower in FEV1-BDR-negative group(P<0.05).5.ΔFVC% was negatively correlated with MMEF%pred,MEF50%pred and MEF25%pred,and the correlation coefficients were-0.270,-0.258,-0.253(P <0.05).ΔFVC% was positively correlated with RV/TLC%pred and the correlation coefficient was 0.222(P<0.05).ΔFVC% was negatively correlated with DLCO%pred and the correlation coefficient was-0.207(P<0.05).ΔFEV1%was negatively correlated with MMEF%pred,MEF50%pred and MEF25%pred,and the correlation coefficients were-0.254,-0.219,-0.253(P < 0.05).ΔFVC%was positively correlated with Fe NO(r=0.255,P<0.01),ΔFEV1% is not correlated with Fe NO(r=0.082,P>0.05).ΔFEV1% and ΔFVC% were positively correlated with IFN-γ,and the correlation coefficients were 0.319 and 0.609(P<0.05).Conclusions:After inhalation of bronchodilators,volume diastolic responsiveness was more pronounced than flow diastolic responsiveness in COPD patients. Moreover,COPD patients with different volume diastolic response had different clinical features,lung function characteristics and airway inflammation levels,which were manifested as COPDFVC-BDR-positive patients had more severe dyspnea,higher risk of acute exacerbation,worse lung ventilation function,heavier lung hyperinflation,worse lung diffusion function,and more serious inflammatory response.And FVC-BDR positivity may be a unique phenotype in COPD patients.