Affiliation:
1. Department of Otorhinolaryngology University of Eastern Finland Joensuu Kuopio Finland
2. Deparment of Allergology Inflammation Center Skin and Allergy Hospital Helsinki University Hospital and University of Helsinki Hospital District of Helsinki and Uusimaa Helsinki Finland
3. Department of Otorhinolaryngology Kuopio University Hospital Wellbeing Services County of North Savo Kuopio Finland
4. Department of Public Health University of Helsinki Helsinki Finland
5. Haartman Institute University of Helsinki Helsinki Finland
Abstract
AbstractBackgroundOur population‐based study has previously shown that being born in winter or spring was associated with adult‐onset asthma. The aim was to study if season of birth (SOB) is associated with airway allergy and related diseases: NSAID exacerbated respiratory disease (N‐ERD), asthma, allergic rhinitis (AR), nonallergic rhinitis (NAR), chronic rhinosinusitis with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP) in Finland.MethodsA randomly sampled retrospective registry‐based follow‐up data (n = 74,868) of patients visiting Hospital District of Helsinki and Uusimaa (HUS) in Finland was used. The birth date, sex, visit date and comorbidities were collected from electronic health record data during visits from 2005 to 2019.ResultsThe mean (SD, range) age of the sample was 34.53 (25.47, 0–102) years, with 48.7 % being men. We divided the whole population in four groups based on the season they were born (SOB‐groups). When observing these four SOB‐groups, the proportion of those having asthma was 43.1%, 42.1%, 41.1%, 42.7%, in winter, spring, summer, and autumn SOB‐groups, respectively. The proportion of those having AR was 12.6%, 12.0%, 10.7%, 12.1%, respectively. When having summer as a reference, being born in any other time of year was significantly associated with AR and, being born in autumn or winter was associated with asthma. No significant association was observed in CRS or N‐ERD or NAR groups in adjusted models.ConclusionsThe study suggests that early life immunological events may have a role a role in pathogenesis of asthma and AR. As no association was observed between SOB and CRSsNP, CRSwNP, N‐ERD or NAR, further studies on this are warranted.