Short term exacerbation risk and exhaled nitric oxide in COPD Romero Linares, Alejandro Alvarez Muro, Lucía Hammadi, A Hoyas-Sánchez, Clara Jiménez Antón, A Almansa López, Angel Casares Martín Moreno, Laura Sánchez Álvarez, Esther Murillo Rodriguez, A Gómez Mora, M Gómez-Pontes Cabrera, T Romero Palacios, Pedro José Alcázar Navarrete, Bernardino Introduction: Exacerbations of chronic obstructive pulmonary disease (COPD) significantly impact morbidity and healthcare utilization. Identifying biomarkers predictive of exacerbation risk can optimize management strategies. We evaluated the role of baseline fractional exhaled nitric oxide (FENO) as a predictor of moderate and severe exacerbations over 90 days. Methods: A prospective cohort study included COPD patients attending pulmonology clinics. Patients were stratified based on baseline FENO levels: FENO <20 ppb and FENO ≥20 ppb. The primary outcome was time-tofirst exacerbation, analysed using Kaplan-Meier survival curves and Cox proportional hazards models. Secondary outcomes included differences in baseline characteristics and hazard ratios (HR) for severe exacerbations. Results: A total of 322 patients were included (220 with FENO <20 ppb, 102 with FENO ≥20 ppb). Kaplan-Meier analysis showed significantly shorter survival time without moderate/severe exacerbations in those with high FENO. Cox regression demonstrated a 3.01-fold increased risk of moderate/severe exacerbations in high FENO (HR: 3.01, 95 % CI: 1.83–4.93; p < 0.001). For severe exacerbations, those patients exhibited a non-significant trend toward increased risk (HR: 2.49, 95 % CI: 0.91–6.86; p = 0.058). Conclusion: Elevated FENO (≥20 ppb) is associated with increased short-term risk of moderate and severe COPD exacerbations. These findings highlight FENO as a potential biomarker for early risk stratification and tailored interventions in COPD patients 2025-05-20T10:24:18Z 2025-05-20T10:24:18Z 2025-04-29 journal article Respiratory Medicine 243 (2025) 108134 https://hdl.handle.net/10481/104159 10.1016/j.rmed.2025.108134 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional Elsevier