Cover illustration for the thesis
Cover illustration: Matilda Östman-Wernerson

Joel Bergqvist – Rhinosinusitis beyond the upper airways


On June 8, Joel Bergqvist defended his thesis for Doctor of Philosophy in Medical Science at the Institute of Clinical Sciences, Sahlgrenska Academy, in the research subject of Otorhinolaryngology

The title of the thesis: Rhinosinusitis beyond the upper airways – Epidemiological aspects

Link directly to the doctoral thesis in GUPEA


Rhinosinusitis (RS) is a prevalent, multi-factorial disease, including several subgroups of disease with different characteristics and pathophysiology. RS symptoms for more than 12 weeks are defined as chronic rhinosinusitis (CRS). The underlying mechanisms likely involve multiple and distinct physiological processes that ultimately result in the inflammation of the sino-nasal mucosa. The potential relationship between upper- and lower-airway diseases would justify the concept of “global airway disease” – a field of increasing interest in research during the last decade. However, there is still much to uncover and a need systematically to investigate the natural history of CRS and the impact of risk factors and comorbidities. This thesis is based on four large, population-based studies from randomly selected population cohorts investigating CRS and the wider definition of non-infections rhinitis (NIR) and their relationship with the lower airways and the esophagus.

Methods and results: Papers I, III and IV are single-center cohorts from Sweden and Norway. Paper II is a multi-center study from 26 centers in Europe and Australia. In Paper I (n=3,612 participants, age 25-75), we found an increased risk of developing NIR among subjects with COPD based on spirometry (OR 1.44, 95% CI 1.05-1.97). Smoking, atopy and occupational exposure to gas, fumes and dust were also risk factors for developing NIR. In Paper II (n=5,901), NIR was strongly associated with COPD at early follow-up (mean age 43) and weaker at later follow-up (mean age 54). Age was a protective factor and female gender was associated with an increased risk of NIR. Paper III is a five-year follow-up in a cohort from Telemark, Norway (n=7,393, age 16-50 at baseline). CRS was associated with an increased risk of developing chronic bronchitis (CB) (OR 3.8, 95% CI 2.65-5.40). Smoking and asthma were also more common among subjects with CRS. Paper IV investigates nocturnal gastroesophageal reflux (nGER) as a potential extra-respiratory comorbidity in CRS. Here, CRS was associated with nGER and the frequency of CRS increased stepwise with increasing numbers of nGER events.

Conclusion: There are several links between chronic upper- and lower-airway diseases. In this thesis, the odds ratio for developing NIR increased among subjects with COPD. The association between NIR and COPD was shown to be age dependent, where the association was more robust at a younger age. Furthermore, the risk of developing CB increased among subjects with CRS and CRS was also associated with nGER in a dose-dependent manner.

The results of this thesis strengthen the evidence on the global airway concept in RS and COPD/CB and highlight the need to evaluate concomitant inflammatory diseases as comorbidities in CRS.

Illustration of the overlap between different chronic upper- and lower-airway diseases.
Illustration of the overlap between rhinosinusitis, nocturnal gastroesophageal reflux, chronic obstructive pulmonary disease, and chronic bronchitis based on findings in this thesis.
MORE INFORMATION about the dissertation

Tid: June 8, 2023, 09:00-11:30 Location: Hjärtats aula, Sahlgrenska Universitetssjukhuset, Vita stråket 12, Göteborg

Supervisor: Johan Hellgren
Co-Supervisors: Anders Andersson, Mogens Bove och Linus Schiöler
Opponent: Wenche Moe Thorstensen, University of Science and Technology, Trondheim, Norway
Examining committee: Helen Seeman-Lodding, Johan Knutsson och Jesper Magnusson