Alcazar-Navarrete, BernardinoRuiz Rodriguez, OliverioConde Baena, PabloRomero Palacios, Pedro JoseAgusti, Alvar2023-02-122023-02-122018-01-010903-1936http://hdl.handle.net/10668/19116Preventing the occurrence of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) is a major therapeutic goal. We hypothesise that persistently increased levels of exhaled nitric oxide (FeNO) during follow-up can identify a group of COPD patients at higher risk of AECOPD.To test this hypothesis, we measured FeNO levels (HypAir FeNO (R), Medisoft; Sorinnes, Belgium) prospectively in 226 clinically stable COPD outpatients at recruitment and during follow-up (at 6 and 12 months). Patients were stratified according to the number of visits with FeNO >= 20 ppb.FeNO was = 20 ppb.FeNO was = 20 ppb in clinically stable COPD outpatients are associated with a significantly higher risk of AECOPD.enObstructive pulmonary-diseaseEosinophilic airway inflammationBlood eosinophilsOverlap syndromeAsthmaMortalityLiferesearch articleopen access10.1183/13993003.01457-20171399-3003https://erj.ersjournals.com/content/erj/51/1/1701457.full.pdf424355100016