Correlation between exhaled nitric oxide and lung function, ACQ7 scores in patients with bronchial asthma

Abstract

Objective To investigate the correlation between fraction of exhaled nitric oxide (FeNO),lung function and the level of bronchial asthma (asthma) control,looking for appropriate methods in airway inflammation monitoring and management in asthmatics.Methods A total of 65 diagnosed asthmatic out-patients since March 2010 to June 2011 according to GINA 2008 criterions were enrolled in this investigation.The patients were asked to complete FeNO measurement,while pulmonary functions,recording FEV1,FEV1％ pred,FVC,FEV1/FVC,PEF,FEF25/75,FEF25/75％,and collecting induced sputum,recording percent of induced sputum eosnophils cell (EOS％).Asthma Control Questionnaire(ACQ7) and Asthma Control Test (ACT) were also required to finished.Results Multiple linear regression analysis showed that FeNO values were affected mainly by age,FEF25/75,FEF25/75 ％,and daytime symptoms,having no significant correlation with body mass index (BMI),allergies or other factors,and also there was no significant correlation with FEV1,FEV1 ％,ACQ7 scores,ACT scores ( P ＞ 0.05 for all),but FeNO values were significant positive correlation to induced sputum EOS％ ( r =0.327,P =0.022).There were significantly negatively correlations between ACQ7 and FEV1,FEV1 ％ (respectively r =-0.491,P =0.000,r =-0.469,P =0.012).Conclusions FeNO can objectively reflect the airway eosinophilic inflammation levels.The younger,the more obvious daytime symptoms,and the higher airway resistance,the higher FeNO levels.FeNO combining with lung function may fully reflect the disease status and the level of asthma control. Key words: Asthma; Fraction of exhaled nitric oxide; Lung function; ACQ7 ; Airway inflammation