Ohfuji Satoko, Miyake Yoshihiro, Arakawa Masashi, Tanaka Keiko, Sasaki Satoshi
Department of Public Health, Osaka City University Graduate School of Medicine, Osaka, Japan.
Pediatr Allergy Immunol. 2009 Jun;20(4):377-84. doi: 10.1111/j.1399-3038.2008.00804.x. Epub 2008 Aug 24.
A number of epidemiological studies have reported an inverse association between increasing sibship size and allergic disorders. The present cross-sectional study assessed the association between the number of siblings and the prevalence of allergic disorders during the past 12 months in Japanese schoolchildren. Study subjects were 22,750 children aged 6-15 yr in Okinawa. The outcomes were based on diagnostic criteria from the International Study of Asthma and Allergies in Childhood. Adjustment was made for age, gender, maternal age at childbirth, duration of breastfeeding, region of residence, smoking in the household, paternal and maternal history of asthma, atopic eczema, and allergic rhinitis, and paternal and maternal educational level. Significant exposure-response associations were observed between increasing total sibship size and all outcomes under investigation. Having two or more older siblings was significantly inversely related to the prevalence of atopic eczema and allergic rhinoconjunctivitis, but not wheeze or asthma. Having two or more younger siblings was independently associated with a decreased prevalence of atopic eczema, but not wheeze, asthma, or allergic rhinoconjunctivitis. The inverse relationships between sibship size and the prevalence of allergic disorders under study were weakened with advancing age, although the interactions between age groups were not statistically significant. No significant interactions were found in the association of having three or more siblings with allergic disorders between children with a positive or negative parental allergic history. These results are likely to support the in utero programming hypothesis because it is probable that the in utero environment would change with parity, although our observations could not refute the hygiene hypothesis.
多项流行病学研究报告称，同胞数量增加与过敏性疾病之间存在负相关。本横断面研究评估了日本学龄儿童的兄弟姐妹数量与过去12个月内过敏性疾病患病率之间的关联。研究对象为冲绳县22750名6至15岁的儿童。研究结果基于儿童哮喘和过敏国际研究的诊断标准。对年龄、性别、母亲分娩时的年龄、母乳喂养时间、居住地区、家庭吸烟情况、父母的哮喘、特应性皮炎和过敏性鼻炎病史以及父母的教育水平进行了调整。在总同胞数量增加与所有调查结果之间观察到显著的暴露-反应关联。有两个或更多哥哥姐姐与特应性皮炎和过敏性鼻结膜炎的患病率显著负相关，但与喘息或哮喘无关。有两个或更多弟弟妹妹与特应性皮炎患病率降低独立相关，但与喘息、哮喘或过敏性鼻结膜炎无关。尽管年龄组之间的相互作用无统计学意义，但随着年龄增长，同胞数量与所研究的过敏性疾病患病率之间的负相关关系减弱。在父母有或无过敏性病史的儿童中，有三个或更多兄弟姐妹与过敏性疾病的关联未发现显著的相互作用。这些结果可能支持子宫内编程假说，因为子宫内环境可能会随着生育次数而改变，尽管我们的观察结果不能反驳卫生假说。
