Being born in autumn or winter is linked to a higher risk of asthma and allergic rhinitis in Finland, according to a recent registry-based study.
A recent study conducted by researchers from the University of Eastern Finland, the University of Helsinki, and Helsinki University Hospital reveals that the season of birth can influence the likelihood of developing allergic rhinitis and asthma in Finland. Specifically, births occurring in autumn or winter show a notable connection with these conditions, while being born in the summer correlates with the lowest instances of asthma and allergic rhinitis.
According to Sanna Salmi, a Professor of Otorhinolaryngology at the University of Eastern Finland, “When we used summer as a comparison, it was evident that being born in any other season had a significant relation to allergic rhinitis. Additionally, those born in autumn or winter had a higher chance of developing asthma. However, we did not find any significant link between the season of birth and chronic rhinosinusitis or NSAID-exacerbated respiratory disease.”
The link between the season of birth and related respiratory allergies may be affected by factors such as changes in light levels, variations in vitamin D metabolism, the presence of certain plants, and air pollution, all of which can influence allergenicity and immune responses, potentially increasing the risk of allergic rhinitis. Previous studies in Finland have indicated that individuals born during winter or spring have a greater risk of facing asthma as adults.
The current study analyzed registry follow-up data of 74,868 patients who sought care in the Hospital District of Helsinki and Uusimaa (HUS) from 2005 to 2019. The collected data included birth dates, gender, dates of hospital visits, and other health conditions. Among the different seasonal birth groups, asthma was found in 43.1% of the winter group, 42.1% in spring, 41.1% in summer, and 42.7% in autumn. Furthermore, allergic rhinitis figures were 12.6% in winter, 12.0% in spring, 10.7% in summer, and 12.1% in autumn.
Published in Clinical and Translational Allergy, the research aimed to determine if the season of birth has a relationship with various airway allergies and related conditions, including NSAID-exacerbated respiratory disease, asthma, allergic rhinitis, nonallergic rhinitis, chronic rhinosinusitis with nasal polyps, and chronic rhinosinusitis without nasal polyps in Finland.
Professor Salmi adds, “Our findings may indicate that the development of chronic rhinosinusitis and NSAID-exacerbated respiratory disease is less influenced by these early life factors; nonetheless, additional studies with larger groups are necessary to validate this.”
