Department of Environmental and Occupational Medicine, School of Public Health, Aarhus University, Bartholins Allé 2, bg 1260, 8000 Aarhus C, Denmark.
Occup Environ Med. 2012 Feb;69(2):99-106. doi: 10.1136/oem.2011.065169. Epub 2011 Oct 28.
To test the hypotheses that current endotoxin exposure is inversely associated with allergic sensitisation and positively associated with non-allergic respiratory diseases in four occupationally exposed populations using a standardised analytical approach.
Data were pooled from four epidemiological studies including 3883 Dutch and Danish employees in veterinary medicine, agriculture and power plants using biofuel. Endotoxin exposure was estimated by quantitative job-exposure matrices specific for the study populations. Dose-response relationships between exposure, IgE-mediated sensitisation to common allergens and self-reported health symptoms were assessed using logistic regression and generalised additive modelling. Adjustments were made for study, age, sex, atopic predisposition, smoking habit and farm childhood. Heterogeneity was assessed by analysis stratified by study.
Current endotoxin exposure was dose-dependently associated with a reduced prevalence of allergic sensitisation (ORs of 0.92, 0.81 and 0.66 for low mediate, high mediate and high exposure) and hay fever (ORs of 1.16, 0.81 and 0.58). Endotoxin exposure was a risk factor for organic dust toxic syndrome, and levels above 100 EU/m(3) significantly increased the risk of chronic bronchitis (p<0.0001). Stratification by farm childhood showed no effect modification except for allergic sensitisation. Only among workers without a farm childhood, endotoxin exposure was inversely associated with allergic sensitisation. Heterogeneity was primarily present for biofuel workers.
Occupational endotoxin exposure has a protective effect on allergic sensitisation and hay fever but increases the risk for organic dust toxic syndrome and chronic bronchitis. Endotoxin's protective effects are most clearly observed among agricultural workers.
使用标准化分析方法，检验以下假设：在四个职业暴露人群中，当前内毒素暴露与过敏致敏呈负相关，与非过敏性呼吸道疾病呈正相关。
数据来自四项包括兽医、农业和生物燃料发电厂的流行病学研究，共包括 3883 名荷兰和丹麦员工。通过针对研究人群的定量职业暴露矩阵来估计内毒素暴露。使用逻辑回归和广义加性模型评估暴露与 IgE 介导的常见过敏原致敏和自我报告健康症状之间的剂量反应关系。调整了研究、年龄、性别、特应性倾向、吸烟习惯和农场童年等因素。通过按研究分层进行分析来评估异质性。
当前内毒素暴露与过敏致敏（低、中、高暴露的比值比分别为 0.92、0.81 和 0.66）和花粉热（比值比分别为 1.16、0.81 和 0.58）的患病率呈剂量依赖性相关。内毒素暴露是有机粉尘毒性综合征的危险因素，暴露水平高于 100 EU/m³时显著增加慢性支气管炎的风险（p<0.0001）。按农场童年分层，除过敏致敏外，无效应修饰。仅在没有农场童年的工人中，内毒素暴露与过敏致敏呈负相关。异质性主要存在于生物燃料工人中。
职业内毒素暴露对过敏致敏和花粉热具有保护作用，但增加了有机粉尘毒性综合征和慢性支气管炎的风险。内毒素的保护作用在农业工人中最为明显。
