Chronic rhinosinusitis associated with chronic bronchitis in a five-year follow-up: the Telemark study

BACKGROUND: Chronic rhinosinusitis (CRS) is associated with generalised airway inflammation. Few studies have addressed the relationship between CRS and chronic bronchitis (CB). METHODS: This prospective study over a five-year period aims to investigate the risk of developing CB in subjects reporting CRS at the beginning of the study. A random sample of 7393 adult subjects from Telemark County, Norway, answered a comprehensive respiratory questionnaire in 2013 and then 5 years later in 2018. Subjects reporting CB in 2013 were excluded from the analyses. New cases of CB in 2018 were analysed in relation to having CRS in 2013 or not. RESULTS: The prevalence of new-onset CB in 2018 in the group that reported CRS in 2013 was 11.8%. There was a significant increase in the odds of having CB in 2018 in subjects who reported CRS in 2013 (OR 3.8, 95% CI 2.65–5.40), adjusted for age, sex, BMI, smoking and asthma. CONCLUSION: In this large population sample, CRS was associated with increased odds of developing CB during a five-year follow-up. Physicians should be aware of chronic bronchitis in patients with CRS.