Nitrogen dioxide exposure and airway responsiveness in individuals with asthma
Nitrogen dioxide exposure and airway responsiveness in individuals with asthma
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DOI：
10.3109/08958378.2014.979960
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发表时间：
2015-01-01
影响因子：
2.1
通讯作者：
Brown, James S.
中科院分区：
文献类型：
--
作者：
Brown, James S.
对照人体暴露研究评估吸入二氧化氮（NO2）对气道对支气管收缩剂的固有反应性的影响，结果好坏参半。总的来说，现有的荟萃分析显示，NO2对哮喘患者气道反应性的影响具有统计学意义。然而，没有荟萃分析对气道反应性变化的临床相关性、原始论文中方法学偏差的可能性以及反应的分布进行全面评估。本文提供的分析表明，有统计学意义的一部分（即70%的哮喘患者在休息时暴露于NO2）在暴露于200至300 ppb NO2 30分钟和暴露于100 ppb NO2 60分钟后，气道反应性增加。气道反应性变化的分布呈对数正态分布，中位数变化为0.75 （NO2引起的激发剂量除以过滤空气暴露引起的激发剂量），几何标准差为1.88。约有四分之一的暴露个体由于二氧化氮暴露而出现临床相关的诱发剂量减少。经历反应性增加的比例在排除个体研究后具有统计学意义和稳健性。结果显示，在运动期间暴露于二氧化氮的个体气道反应性变化很小。
Controlled human exposure studies evaluating the effect of inhaled nitrogen dioxide (NO2) on the inherent responsiveness of the airways to challenge by broncho-constricting agents have had mixed results. In general, existing meta-analyses show statistically significant effects of NO2 on the airway responsiveness of individuals with asthma. However, no meta-analysis has provided a comprehensive assessment of the clinical relevance of changes in airway responsiveness, the potential for methodological biases in the original papers, and the distribution of responses. This paper provides analyses showing that a statistically significant fraction (i.e. 70% of individuals with asthma exposed to NO2 at rest) experience increases in airway responsiveness following 30-min exposures to NO2 in the range of 200 to 300 ppb and following 60-min exposures to 100 ppb. The distribution of changes in airway responsiveness is log-normally distributed with a median change of 0.75 (provocative dose following NO2 divided by provocative dose following filtered air exposure) and geometric standard deviation of 1.88. About a quarter of the exposed individuals experience a clinically relevant reduction in their provocative dose due to NO2 relative to air exposure. The fraction experiencing an increase in responsiveness was statistically significant and robust to exclusion of individual studies. Results showed minimal change in airway responsiveness for individuals exposed to NO2 during exercise.