哮喘联盟

   摘要
   背景：尽管已有研究显示在健康儿童中环境空气污染与肺功能降低有关，目前仍尚缺污染对哮喘患者影响的纵向研究。
   目的：本文旨在研究纵向哮喘研究中的污染效应及药物控制后的效应改变。
   方法：本研究纳入参与为期4年的临床试验的哮喘儿童1003例，检查肺功能和乙酰胆碱反应性（PC20）与臭氧、一氧化碳（CO）、二氧化氮、二氧化硫浓度的联系。进一步研究布地奈德和奈多罗米是否改变污染效应。每日污染物浓度与居住地邮编相关联。运用线性混合模型评估个体污染物浓度与FEV1、最大肺活量（FVC）占预计值百分比，、FEV1/FVC比值以及经季节性和其他混杂因素校正后的PC20之间的关系。
   结果：数日及一周平均CO浓度与使用支气管扩张剂后的FEV1占预计值百分比负相关（每四分位数间距变化分别为： -0.33 [95% CI, -0.49 to -0.16] and -0.41 [95% CI, -0.62 to -0.21]），也与FVC负相关（-0.19 [95% CI, -0.25 to -0.07] and -0.25 [95% CI, -0.43 to -0.07]）。长期4个月平均CO浓度与支气管扩张剂使用前的FEV1占预计值百分比(-0.36 [95% CI, -0.62 to -0.10] ）及FVC（-0.21 [95% CI, -0.42 to -0.01]）负相关。4个月平均CO浓度及臭氧浓度与 FEV1/FVC比值负相关 (P < .05)。4个月平均二氧化氮浓度增加与使用支气管扩张剂后的FEV1占预计值百分比及FVC占预计值百分比降低有关。长期SO2暴露与PC20降低相关（每四分位间距百分比变化，-6% [95% CI, -11% to -1.5%])。治疗增加了短期CO对PC20的负效应。
   结论：空气污染对于哮喘儿童肺功能及PC20具有不良影响。应用控制药物不能有效保护CO对PC20的效应，反而使之恶化。本临床试验设计运用排除适应症混杂的治疗，评估污染效应变化。
 

（杨冬 审校）
JAllergyClinImmunol. 2015Jun29.pii:S0091-6749(15)00769-1.doi:10.1016/j.jaci.2015.05.028. [Epub ahead of print]

 

Ambient air pollution, lung function, and airway responsiveness in asthmatic children.
 

Ierodiakonou D1, Zanobetti A2, Coull BA3, Melly S2, Postma DS4, Boezen HM5, Vonk JM5, Williams PV6, Shapiro GG6, McKone EF7, Hallstrand TS8, Koenig JQ9, Schildcrout JS10, Lumley T11, Fuhlbrigge AN12, Koutrakis P2,Schwartz J2, Weiss ST12, Gold DR13; Childhood Asthma Management Program Research Group.
 

Abstract
BACKGROUND:Although ambient air pollution has been linked to reduced lung function in healthy children, longitudinal analyses of pollution effects in asthmatic patients are lacking.
OBJECTIVE:We sought to investigate pollution effects in a longitudinal asthma study and effect modification by controller medications.
METHODS:We examined associations of lung function and methacholine responsiveness (PC20) with ozone, carbon monoxide (CO), nitrogen dioxide, and sulfur dioxide concentrations in 1003 asthmatic children participating in a 4-year clinical trial. We further investigated whether budesonide and nedocromil modified pollution effects. Daily pollutant concentrations were linked to ZIP/postal code of residence. Linear mixed models tested associations of within-subject pollutant concentrations with FEV1 and forced vital capacity (FVC) percent predicted, FEV1/FVC ratio, and PC20, adjusting for seasonality and confounders.
RESULTS:Same-day and 1-week average CO concentrations were negatively associated with postbronchodilator percent predicted FEV1 (change per interquartile range, -0.33 [95% CI, -0.49 to -0.16] and -0.41 [95% CI, -0.62 to -0.21], respectively) and FVC (-0.19 [95% CI, -0.25 to -0.07] and -0.25 [95% CI, -0.43 to -0.07], respectively). Longer-term 4-month CO averages were negatively associated with prebronchodilator percent predicted FEV1 and FVC (-0.36 [95% CI, -0.62 to -0.10] and -0.21 [95% CI, -0.42 to -0.01], respectively). Four-month averaged CO and ozone concentrations were negatively associated with FEV1/FVC ratio (P < .05). Increased 4-month average nitrogen dioxide concentrations were associated with reduced postbronchodilator FEV1 and FVC percent predicted. Long-term exposures to sulfur dioxide were associated with reduced PC20 (percent change per interquartile range, -6% [95% CI, -11% to -1.5%]). Treatment augmented the negative short-term CO effect on PC20.
CONCLUSIONS:Air pollution adversely influences lung function and PC20 in asthmatic children. Treatment with controller medications might not protect but rather worsens the effects of CO on PC20. This clinical trial design evaluates modification of pollution effects by treatment without confounding by indication.
 

JAllergyClinImmunol. 2015Jun29.pii:S0091-6749(15)00769-1.doi:10.1016/j.jaci.2015.05.028. [Epub ahead of print]