Feno predicts short term risk of moderate/severe copd exacerbations

Abstract

<b>Introduction:</b> raised T2 biomarkers (either blood eosinophil count or FeNO) in COPD are associated to an increased risk of future moderate and severe COPD exacerbations. However, it is unknown if increased FeNO levels are associated with an increased risk of short-term COPD exacerbations <b>Methods:</b> an observational, prospective, multicentric study was performed in respiratory outpatient clinics in Spain. Adult patients with previous COPD diagnosis were included. FeNO was measured at baseline visit at a 50 mL/s flow with a chemiluminescence NO analyzer (HypAir FeNO ®), and study population was divided in two groups according to high (≥20 ppb) or normal FeNO levels. Moderate and severe exacerbations at 3 months from baseline visit were recorded. A Kaplan- Meier and Cox regression analysis were carried out to determine differences among study groups. Statistical significance was set a p value &lt;0.05 <b>Results:</b> 322 patients were invited to participate and 303 were finally included, mostly male (89.1%) with a mean age 71 years-old and moderate airflow limitation (FEV1 56%). 28% of the entire population were active smokers and 59% were receiving an ICS containing-regimen. 96 patients (31%) showed an increased FeNO at baseline. During 3 month follow up, those with high FeNO showed an increased risk for moderate/severe COPD exacerbations (HR 2.76, 95% CI 1.66-4.57, p&lt;0.001) and a shorter time to first event. Multivariate analysis showed that baseline FeNO was associated with an increased risk for 3-month exacerbations, with an increased risk of 3% per each 1 ppb. <b>Conclusions:</b> COPD patients with raised FeNO have an increased risk for short term exacerbations