National Centre for Epidemiology and Population Health, The Australian National University, Canberra, Australia.
Pediatr Allergy Immunol. 2011 May;22(3):327-33. doi: 10.1111/j.1399-3038.2010.01099.x. Epub 2010 Sep 30.
Observations of increasing allergy prevalence with decreasing distance from the Equator and positive associations with ambient ultraviolet radiation have contributed to a growing interest in the possible role of vitamin D in the etiology of allergy. The aims of this study were to describe any latitudinal variation in the prevalence of childhood allergy in Australia and to evaluate, in parallel, the individual associations between ultraviolet radiation (UVR)- and vitamin D-related measures and hayfever asthma and both conditions. Participants were population-based controls who took part in a multicenter case-control study, aged 18-61 yr and resident in one of four study regions ranging in latitude from 27°S to 43°S. Data were derived from a self-administered questionnaire, interview and examination by a research officer and biologic sampling. Latitude and longitude coordinates were geocoded from participants' residential locations and climatic data were linked to postcodes of current residence. Stored serum was analyzed for 25-hydroxyvitamin D concentrations and silicone rubber casts of the skin were used as an objective measure of cumulative actinic damage. There was an inverse latitude gradient for asthma (a 9% decrease per increasing degree of latitude); however, this pattern did not persist after adjusting for average daily temperature. There was no association between any of the UVR- or vitamin D-related measures and childhood asthma, but greater time in the sun in winter between the ages 6-15 yr was associated with an increase in the odds of having hayfever [adjusted odds ratios (OR) 1.29; 95% CI 1.01-1.63]. Oral supplementation with cod liver oil in childhood increased the odds of a history of having both asthma and hayfever (2.87; 1.00-8.32). Further investigation of the possible role of early vitamin D supplementation in the development of allergy is warranted. Our results also suggest that solar exposure during childhood may be important in allergic sensitization. Plausible explanations, including biologic mechanisms, exist for both observations.
随着距赤道距离的缩短，过敏症的发病率呈上升趋势，且与环境紫外线辐射呈正相关，这使得人们对维生素 D 在过敏发病机制中的可能作用产生了浓厚的兴趣。本研究的目的是描述澳大利亚儿童过敏症发病率的纬度变化，并同时评估紫外线辐射（UVR）和维生素 D 相关指标与花粉热哮喘以及这两种疾病之间的个体关联。参与者为参与多中心病例对照研究的基于人群的对照者，年龄为 18-61 岁，居住在纬度范围从 27°S 至 43°S 的四个研究区域之一。数据来自自我管理的问卷调查、研究人员进行的访谈和检查以及生物样本采集。从参与者的居住地址获取纬度和经度坐标，并将气候数据与当前居住的邮政编码相关联。分析储存的血清 25-羟维生素 D 浓度，使用皮肤硅橡胶铸型作为累积光损伤的客观测量指标。哮喘存在与纬度的负相关梯度（纬度每增加 1 度，哮喘发病率降低 9%）；但是，在调整平均每日温度后，这种模式并不存在。任何 UVR 或维生素 D 相关指标与儿童哮喘均无关联，但是 6-15 岁期间冬季晒太阳时间增加与花粉热的患病几率增加相关（校正比值比 [OR] 1.29；95%置信区间 [CI] 1.01-1.63）。儿童时期口服鱼肝油补充剂增加了同时患有哮喘和花粉热的病史的几率（2.87；1.00-8.32）。有必要进一步研究早期维生素 D 补充在过敏发展中的可能作用。我们的研究结果还表明，儿童时期的太阳暴露可能在过敏致敏中很重要。这两种观察结果都存在合理的解释，包括生物学机制。
