The Relationship of Fractional Exhaled Nitric Oxide in Patients with AECOPD

Abstract

Objective

To identify the relationship between patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and their fractional-exhaled nitric oxide (FeNO) levels.

Methods

Patients diagnosed with AECOPD in the respiratory department of Beijing Chaoyang Hospital from June 2017 to August 2019 were recorded. The demographic data, FeNO value, peripheral blood eosinophil count, number of acute exacerbations in the past year, pulmonary function test, use of inhaled glucocorticoids (ICS) and other data were collected and analyzed. FeNO was measured again three months after discharge, the participants were assessed to determine if the stable period criteria were met.

Results

A total of 214 patients met the requirements of this study. 25ppb for FeNO was used as the cutoff for further analysis. The proportion of males, number of acute exacerbations in the past year, number of ICS users, leukocyte count and eosinophil count in the high FeNO-level group was significantly higher than that in the low-level group (P < 0.05). The results showed that the number of acute exacerbations in the past year, number of ICS users, and eosinophil count were statistically significant in the model (P < 0.05). The study also showed that the level of FeNO in the acute exacerbation phase was significantly higher than that in the stable phase. The ROC curve that the area under the curve used by FeNO to predict ICS used is 0.631 (95% CI: 0.526–0.736), and the corresponding P value is 0.022.

Conclusion

FeNO is closely related to activated T2 inflammation and eosinophil count in COPD patients. The FeNO levels can be used as an index to evaluate the severity of COPD and predict the recovery of activity after ICS treatment. FeNO can predict the use of ICS and is a beneficial supplement to eosinophils.

Keywords:

• fractional exhaled nitric oxide
• chronic obstructive pulmonary disease
• acute exacerbation
• airway inflammation

Ethical Statement

The study was conducted in accordance with the Declaration of Helsinki (as revised in 2013). The study was approved by the Ethics Committee of Beijing ChaoYang Hospital (NO.: NCT05059873). Informed consent was waived by our Ethics Committee because of the retrospective nature of our study. Our research involves patient data information, which is kept confidential under ethical regulations.

Acknowledgments

The source of support for the study was no help from others. The research was carried out without funding.

Disclosure

The authors declare that there are no conflicts of interest regarding the publication of this article.