Supplementary Material for: Associations of Current Wheeze and Body Mass Index with Perennial and Seasonal Allergic Rhinitis in Young Adults

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.

研究背景：已有研究证实哮喘与变应性鼻炎（allergic rhinitis, AR）可共存，且二者均与肥胖存在明确关联。但目前鲜有研究区分常年性变应性鼻炎（perennial AR, PAR）与季节性变应性鼻炎（seasonal AR, SAR）两种亚型，探讨其分别与哮喘及肥胖的关联。本研究旨在评估日本青年群体中当前喘息症状与两种亚型AR的共存情况，以及体重指数（body mass index, BMI）对这两类疾病的影响。
研究方法：本研究于2011年至2016年间纳入北海道大学一年级学生作为研究对象。针对11917名非吸烟青年群体，每年开展问卷调查，收集当前喘息症状、PAR及SAR的患病数据。本研究分别评估了当前喘息症状与BMI对两种亚型AR的影响差异。
研究结果：尽管PAR与SAR均与当前喘息症状存在显著关联，但两种AR亚型对当前喘息症状的影响存在显著差异（PAR的比值比（Odds Ratio, OR）为2.46，SAR的OR为1.29）。当将所有研究对象按是否合并两种AR亚型分为4组时，合并PAR的群体其当前喘息症状患病率显著高于未合并PAR的群体（p < 0.001）；然而，合并与未合并SAR的群体之间，当前喘息症状患病率并无统计学差异。多项分类回归分析结果显示，与仅合并SAR（未合并PAR）的群体相比，同时合并PAR和/或SAR的群体，其喘息症状与AR的关联强度更高。PAR患病率与BMI无显著关联；与之相反，低BMI与SAR患病率升高显著相关（p < 0.05）。
研究结论：对PAR与SAR的对比分析表明，两种AR亚型分别与当前喘息症状及BMI存在不同的关联模式。