Short term exacerbation risk and exhaled nitric oxide in COPD

Abstract

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