Burr M L, Emberlin J C, Treu R, Cheng S, Pearce N E
Centre for Applied Public Health Medicine, University of Wales College of Medicine, Cardiff, UK.
Clin Exp Allergy. 2003 Dec;33(12):1675-80. doi: 10.1111/j.1365-2222.2003.01816.x.
Although pollens are major allergens associated with allergic rhinoconjunctivitis and asthma, there is little information about the relative prevalence of these conditions in populations with different pollen exposures.
The purpose of this study was to investigate the relationship between pollen exposure and allergic symptoms among children in different countries.
An ecological analysis was conducted to see whether pollen exposure (pollen counts, and duration and severity of pollen seasons) is associated with symptoms of allergic rhinoconjunctivitis, asthma and atopic eczema in 28 centres within 11 countries (nine being in Europe). Data on the prevalence of symptoms in 13-14-year olds were based on the responses to the written questionnaires from the International Study of Asthma and Allergies in Childhood (ISAAC). The analysis was adjusted for gross national product and mean annual relative humidity.
There was little relationship between pollen exposure and symptom prevalence, except for a significant inverse association between grass pollen counts and lifetime prevalence of the symptoms of allergic rhinitis (P=0.03). Almost all the regression coefficients were negative. The associations were even weaker and all non-significant when the analyses were conducted within countries, using a random intercept fixed slope model, but there was still no evidence of a positive association between pollen exposure and symptoms.
There is a weak but consistent tendency for the prevalence of allergic symptoms to be inversely associated with pollen exposure. This finding accords with evidence from several countries, suggesting that the prevalence of hayfever and asthma tends to be lower in rural than in urban areas, and lowest among people living on farms. Exposure to allergenic pollen in early life does not appear to increase the risk of acquiring symptoms of respiratory allergy, and may even give some protection against them.
尽管花粉是与变应性鼻结膜炎和哮喘相关的主要变应原，但关于不同花粉暴露人群中这些疾病的相对患病率的信息却很少。
本研究旨在调查不同国家儿童中花粉暴露与变应性症状之间的关系。
进行了一项生态学分析，以观察花粉暴露（花粉计数、花粉季节的持续时间和严重程度）是否与11个国家（9个在欧洲）的28个中心的变应性鼻结膜炎、哮喘和特应性皮炎症状相关。13 - 14岁儿童症状患病率的数据基于对儿童哮喘和变应性疾病国际研究（ISAAC）书面问卷的回答。分析针对国民生产总值和年平均相对湿度进行了校正。
花粉暴露与症状患病率之间几乎没有关系，除了草花粉计数与变应性鼻炎症状的终生患病率之间存在显著的负相关（P = 0.03）。几乎所有回归系数均为负值。当使用随机截距固定斜率模型在各国国内进行分析时，关联甚至更弱且均无统计学意义，但仍没有证据表明花粉暴露与症状之间存在正相关。
变应性症状的患病率与花粉暴露呈负相关，这种趋势虽弱但一致。这一发现与几个国家的证据相符，表明花粉症和哮喘的患病率在农村地区往往低于城市地区，在农场生活的人群中最低。早年暴露于致敏花粉似乎不会增加出现呼吸道变应性症状的风险，甚至可能提供一定的保护作用。
