Exhaled nitric oxide in relation to asthma control: A real-life survey.

Background: Asthma is characterised by chronic airway inflammation, a complex cascade of events, mostly sustained by eosinophil recruitment and activation. Fractional exhaled nitric oxide (FeNO) is a surrogate marker of airway inflammation closely associated with bronchial eosinophilia. FeNO is used to define asthma phenotype, to assess eosinophilic inflammatory severity and to predict corticosteroid responsiveness. Objective: The aim of this study was to investigate whether FeNO may be associated with some clinical and functional factors in asthmatics evaluated in a real life setting. Methods: Globally 363 patients (150 males, mean age 46.3 years) with asthma were consecutively evaluated. The following parameters were assessed: history, including comorbidities, physical examination, body mass index (BMI), lung function, asthma control grade, asthma control test (ACT), and FeNO. Results: FeNO values were significantly higher in patients with poorly controlled asthma (p < 0.01), asthma symptoms (p=0.015), wheezing (p < 0.001), rhinitis diagnosis, (p=0.049) and rhinitis symptoms (p=0.019), but lower in patients with GERD (p=0.024) and pneumonia history (p=0.048). FeNO values increased in patients with the lowest corticosteroid dose (p=0.031). FeNO values > 25 ppb were associated with poorly controlled asthma (OR 3.71), asthma signs (OR 3.5) and symptoms (OR 1.79). A FeNO value cut-off of 29.9 ppb was fairly predictive of (AUC 0.7) poorly controlled asthma. Conclusions: FeNO assessment in clinical practice may be a useful tool for monitoring asthmatics as it is associated with several clinical factors, including asthma control. (C) 2015 SEICAP. Published by Elsevier Espana, S.L.U. All rights reserved.