Lack of Association between Inhaled Corticosteroid Use Based on the Exhaled Nitric Oxide and Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Abstract

Background: Fractional exhaled nitric oxide (FeNO) is known to useful biomarker fordetecting eosinophilic airway inflammation. However, there is a lack of evidence regardingthe role of FeNO in chronic obstructive pulmonary disease (COPD). We aimedto assess whether elevated FeNO and its impact on treatment change into an inhaledcorticosteroid (ICS)-containing regimen and association with acute exacerbation (AE)in patients with COPD. Methods: We retrospectively analyzed 107 COPD patients without a history of asthmafrom March 2016 to December 2019. The patients whose FeNO value was more than50 parts per billion (ppb) were defined into the high FeNO group. Multivariable analysiswith logistic regression was used to identify factors associated with AE in COPD. Results: The median FeNO value was 32 ppb (interquartile range, 19 to 45) and 34(20.0%) patients were classified as high FeNO group (median 74 ppb). In the high FeNOgroup, changes in inhaler treatment into an ICS-containing regimen occurred in 23 of34 patients after the measurement of FeNO. In multivariate analysis, high FeNO was nota contributing factor for AE, but only the high blood eosinophil count (≥300 cells/μL)was associated with AE (adjusted odds ratio, 2.63; 95% confidence interval, 1.01 to 6.91;p=0.049). Conclusion: High FeNO value had a significant impact on the prescription of ICSs inCOPD patients, but it did not show a significant association with AE either on its own orwith changes in treatment.