Background

Studies have reported protective and adverse associations between microbial exposure and childhood asthma. However, among children with asthma the relationships between endotoxin and exercise-induced bronchospasm (EIB) is less clear.

Objective

We investigated the association between exposure to endotoxin in house dust with atopy and EIB in children with asthma.

Methods

A cross-sectional survey was conducted among schoolchildren (aged 7–17 years) in the province of Saskatchewan, Canada. A subpopulation with asthma (n = 116) were identified from 335 participants using a validated asthma algorithm. We determined atopy among the asthma subpopulation by skin prick testing (SPT) while EIB was evaluated using exercise challenge testing (ECT). Dust samples were collected from mattress and play area floors, and endotoxin was measured in dust extracts. Logistic regression analyses were used to explore associations between endotoxin with atopy and EIB.

Results

Among the 116 children with asthma, 99 completed SPT and all had completed ECT. Of these, 71/99 (71.7%) were atopic and 26/116 (22.4%) had EIB. Exposure to high play area endotoxin concentration [adjusted odds ratio (aOR) = 0.15, 95% CI: 0.03–0.85] and load (aOR = 0.11, 95% CI: 0.02–0.73) were negatively associated with atopy. In contrast, EIB was positively associated with high mattress endotoxin concentration (aOR = 6.01, 95% CI: 1.20–30.13).

Conclusion

Indoor microbial endotoxin exposure has varied associations with atopy and exercise-induced bronchospasm among children with asthma.

中文翻译：

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哮喘儿童房尘中的内毒素与特应性与运动诱发的支气管痉挛之间的关系

背景

研究报告了微生物暴露与儿童哮喘之间的保护性和不良关联。然而，在哮喘患儿中，内毒素与运动诱发的支气管痉挛（EIB）之间的关系尚不清楚。

客观的

我们调查了哮喘儿童暴露于房尘中的特应性内毒素与EIB之间的关系。

方法

在加拿大萨斯喀彻温省的学龄儿童（7-17岁）中进行了横断面调查。 使用经过验证的哮喘算法从335名参与者中识别出一个哮喘亚群（n = 116）。我们通过皮肤点刺试验（SPT）确定了哮喘亚群中的特应性疾病，而EIB是通过运动激发试验（ECT）进行评估的。从床垫和游乐区地板上收集灰尘样品，并测量灰尘提取物中的内毒素。Logistic回归分析用于探讨特应性内毒素与EIB之间的关系。

结果

在116名哮喘儿童中，有99名完成了SPT，并且全部完成了ECT。其中，特应性过敏的占71/99（71.7％），EIB占26/116（22.4％）。暴露于高运动区域内毒素浓度[调整比值比（aOR）= 0.15，95％CI：0.03-0.85]和负荷（aOR = 0.11，95％CI：0.02-0.73）与过敏症呈负相关。相反，EIB与高床垫内毒素浓度呈正相关（aOR = 6.01，95％CI：1.20–30.13）。

结论

在哮喘儿童中，室内微生物内毒素暴露与特应性和运动诱发的支气管痉挛有多种关联。