School of Forestry and Environmental Studies, Yale University, New Haven, CT 06511, USA.
Epidemiology. 2012 Jan;23(1):55-63. doi: 10.1097/EDE.0b013e31823b66b8.
Previous studies on the associations between ambient pollen exposures and daily respiratory symptoms have produced inconsistent results. We investigated these relationships in a cohort of asthmatic children using pollen exposure models to estimate individual ambient exposures.
Daily symptoms of wheeze, night symptoms, shortness of breath, chest tightness, persistent cough, and rescue medication use were recorded in a cohort of 430 children with asthma (age 4-12 years) in Connecticut, Massachusetts, and New York. Daily ambient exposures to tree, grass, weed, and total pollen were estimated using mixed-effects models. We stratified analyses by use of asthma maintenance medication and sensitization to grass or weed pollens. Separate logistic regression analyses using generalized estimating equations were performed for each symptom outcome and pollen type. We adjusted analyses for maximum daily temperature, maximum 8-hour average ozone, fine particles (PM2.5), season, and antibiotic use.
Associations were observed among children sensitized to specific pollens; these associations varied by use of asthma maintenance medication. Exposures to even relatively low levels of weed pollen (6-9 grains/m(3)) were associated with increased shortness of breath, chest tightness, rescue medication use, wheeze, and persistent cough, compared with lower exposure among sensitized children on maintenance medication. Grass pollen exposures ≥ 2 grains/m(3) were associated with wheeze, night symptoms, shortness of breath, and persistent cough compared with lower exposure among sensitized children who did not take maintenance medication.
Even low-level pollen exposure was associated with daily asthmatic symptoms.
以往关于环境花粉暴露与每日呼吸道症状之间关联的研究结果并不一致。我们使用花粉暴露模型来评估个体环境暴露情况，对康涅狄格州、马萨诸塞州和纽约的 430 名哮喘儿童进行了一项队列研究，调查了这些关系。
康涅狄格州、马萨诸塞州和纽约的 430 名哮喘儿童（4-12 岁）每天记录气喘、夜间症状、呼吸急促、胸闷、持续咳嗽和使用急救药物的情况。使用混合效应模型估计每日树木、草、杂草和总花粉的环境暴露情况。我们根据使用哮喘维持药物和对草或杂草花粉的敏感性对分析进行分层。使用广义估计方程分别对每个症状结果和花粉类型进行逻辑回归分析。我们调整了分析，以考虑每日最高温度、最大 8 小时平均臭氧、细颗粒物（PM2.5）、季节和抗生素使用情况。
在对特定花粉敏感的儿童中观察到了关联；这些关联因使用哮喘维持药物而有所不同。与使用维持药物的过敏儿童的较低暴露相比，即使是相对较低水平的杂草花粉（6-9 粒/m3）暴露也与呼吸急促、胸闷、急救药物使用、气喘和持续咳嗽有关。与未服用维持药物的过敏儿童的较低暴露相比，草花粉暴露≥2 粒/m3与气喘、夜间症状、呼吸急促和持续咳嗽有关。
即使是低水平的花粉暴露也与每日哮喘症状有关。
