Analysis of the Differences in Small Airway Function and FeNO Changes between Clinical Control of Asthma and Cough-variant Asthma
Objective:To explore the differences in small airway function and fractional exhaled nitric oxide(FeNO)changes between clinically controlled asthma(CCA)and cough-variant asthma(CVA),and to analyze the value of different indexes in the diagnosis of CVA.Method:A retrospective analysis was performed on the case data of 51 patients with CCA and 51 patients with CVA in Xiamen Haicang Hospital between January 2021 and December 2023.The pulmonary ventilation function index[forced vital capacity as a percentage of predicted value(FVC%pred),forced expiratory volume in the first second as a percentage of predicted value(FEV1%pred),peak expiratory flow as a percentage of predicted value(PEF%pred)],small airway function indexes[forced expiratory flow at 25%-75%of vital capacity as a percentage of predicted value(FEF25%-75%%pred),forced expiratory flow after 50%of vital capacity as a percentage of predicted value(FEF50%%pred),forced expiratory flow after 75%of vital capacity as a percentage of predicted value(FEF75%%pred)]and FeNO were compared between two groups.The relationship between FeNO and airway function indexes was analyzed by Pearson correlation analysis.The value of FeNO and small airway function indexes in the diagnosis of CVA was analyzed by receiver operating characteristic(ROC)curves.Result:Compared with CCA group,FEV1%pred,PEF%pred,FEF25%-75%%pred、FEF50%%pred、FEF75%%pred were lower,while FeNO was higher in CVA group(P<0.05).The results of Pearson correlation analysis showed that airway function indexes were negatively correlated with FeNO(P<0.05).The results of ROC curves analysis showed that AUC values of FEF25%-75%%pred、FEF50%%pred、FEF75%%pred and FeNO in the diagnosis of CVA were 0.824,0.836,0.790 and 0.793,all showing certain diagnosis value(P<0.001),but there was no significant difference in AUC among all indexes(P>0.05).Conclusion:Compared with CCA patients,small airway function is worse,and FeNO is higher in CVA patients.FEF25%-75%%pred,FEF50%%pred,FEF75%%pred and FeNO all have certain value in the diagnosis of CVA.
Small airway functionFractional exhaled nitric oxideClinically controlled asthmaCough-variant asthma