Background: Chronic rhinosinusitis (CRS) is a common disease of the upper airways causing nasal obstruction, loss of smell, facial pain and poor quality of life. Studies on CRS in COPD are scarce.

Aims: To study the impact of CRS in COPD in terms of risk of exacerbations.  

Methods: We identified patients with COPD, aged ? 30 years, registered in the Swedish National Airway Register between January 2017 and August 2020. Patients were stratified for the absence or presence of CRS, defined as ?2 prescriptions of nasal corticosteroids within one year before inclusion, and followed until January 2021 for moderate (prescription of oral corticosteroids) and severe (hospital admission for respiratory cause) exacerbations in national registries. A sensitivity analysis excluding patients with allergic rhinosinusitis (defined as additional prescription of antihistamins) was done.

Results: Of the 45350 eligible COPD patients, 2539 (5.6%) had CRS. Patients with and without CRS respectively had similar age (71±9 vs 72±9 years), sex (male: 41% vs. 44%), BMI (28±13 vs. 27±13), CAT score (14±8 vs 13±7) and FEV1 % pred. (62±18 vs 60±18), while those with CRS were less often active smokers (28% vs 38%). Patients with CRS had an elevated hazard ratio (HR) for moderate exacerbations (HR 1.74; (95% CI:1.61-1.88), but not for severe exacerbations (HR 1.01, 95% CI: 0.95?1.08), adjusted for age, sex, smoking and FEV1. Most CRS patients (n=1622 (64%)) did not use antihistamins and those patients had similar results.

Conclusion: In this nationwide cohort study, CRS was associated with a higher risk of moderate exacerbations in COPD and should be considered in the management of COPD.