LAUSR

Background: The coexistence of asthma and allergic rhinitis (AR) and its distinct association with obesity have been reported. However, few studies have differentiated the two types of AR, i.e., perennial (PAR) and seasonal AR (SAR), with regard to their associations with asthma and obesity. The aim of this study was to evaluate the coexistence of current wheeze and two types of AR and the impact of body mass index (BMI) on these two conditions in Japanese young adults. Methods: First-year students from Hokkaido University were enrolled into this study from 2011 to 2016. A questionnaire survey including the prevalence of current wheeze, PAR, and SAR every year for 11,917 nonsmoking young adults was conducted. The difference in the impact of current wheeze and BMI on these two types of AR was separately evaluated. Results: Although both PAR and SAR were significantly associated with current wheeze, the impact of these two AR types on current wheeze was different (OR for PAR = 2.46 vs. OR for SAR = 1.29). When we classified all of the subjects into 4 groups with or/and without the two types of AR, the prevalence of current wheeze was significantly higher in subjects with PAR than in those without PAR (p < 0.001). However, the prevalence of current wheeze did not differ between subjects with or without SAR. Multinomial regression analyses showed that the association of wheeze with PAR and/or SAR was stronger compared to that of wheeze with SAR without PAR. The prevalence of PAR was not associated with BMI. Contrarily, a low BMI was significantly associated with a high SAR prevalence (p < 0.05). Conclusion: Comparisons between PAR and SAR showed that the conditions are differentially associated with current wheeze and BMI.