Clinical trial of air cleaners to improve indoor air quality and COPD health

描述（由申请人提供）：慢性阻塞性肺疾病（COPD）是一种以肺损伤和炎症为特征的进行性疾病。戒烟可以减缓疾病进展；然而，并非所有人都能从戒烟中受益，许多人尽管戒烟了，但仍有气道炎症和严重的呼吸道疾病。目前，目前的治疗策略侧重于通过药物控制疾病和避免加剧疾病的因素。虽然室外空气污染已知对慢性阻塞性肺病的发病率和死亡率有不利影响，但室内环境尤其令人担忧，因为大多数人大部分时间都在室内度过，而且就个人而言，与室外空气不同，室内空气是可以改变的；因此，策略可以强调减少患者家中的污染物暴露。重要的是，我们的研究小组最近的证据表明，在患有慢性阻塞性肺病的前吸烟者家中，室内空气污染物浓度（颗粒物（PM）和二氧化氮（NO2））的增加与呼吸系统疾病有关，包括呼吸系统症状的增加、生活质量的下降、病情恶化的风险和医疗保健利用的增加。我们的小组已经证明，使用带有HEPA过滤器的便携式空气净化器的家庭干预措施成功地降低了PM浓度，并且在空气净化器中添加一个额外的碳过滤器可以降低二氧化氮浓度。我们还表明，空气净化器干预策略可改善其他慢性呼吸道疾病（包括哮喘儿童）的呼吸道症状，但尚不清楚它是否对成人COPD患者有效。关于在COPD患者家中放置便携式空气净化器以减少室内污染物和改善COPD健康的有效性的类似研究尚未开展。为了弥合从流行病学证据到可以为临床实践提供信息的研究之间的差距，我们提出了一项家庭干预研究，以测试有针对性地降低COPD前吸烟者家中室内污染物浓度是否会改善呼吸健康。这些目标将通过一项随机对照试验（n=120）来实现，每组60名患有慢性阻塞性肺病的前吸烟者接受HEPA和碳过滤器空气净化器或假空气净化器的安置。我们的目的是确定空气净化器干预是否会改善呼吸系统症状、生活质量、肺功能和降低恶化风险（具体目标#1）；以及它是否与已知与COPD长期预后相关的中期结果指标相关，包括气道（诱导痰）和全身（血清和尿液）炎症和氧化应激标志物（Specific Aim #2）。我们的研究目标是建立在一个完善的基础设施的研究人员与互补的专业领域。我们预计这项研究的结果将为旨在降低COPD发病率的临床实践指南和卫生保健政策提供信息。随着慢性阻塞性肺病成为美国第三大死亡原因，制定降低发病率的策略是一项重要的公共卫生优先事项。

DESCRIPTION (provided by applicant): Chronic obstructive pulmonary disease (COPD) is a progressive disease characterized by lung injury and inflammation. Smoking cessation can slow disease progress; however, not all people benefit from quitting and many continue to have airway inflammation and significant respiratory morbidity despite abstinence from smoking. At present, the current therapeutic strategy focuses on control of illness through medications and avoidance of factors that exacerbate the disease. Although outdoor air pollution has known adverse effects on COPD morbidity and mortality, the indoor environment is of particular concern as most people spend the majority of their time indoors and at the individual level, indoor air, unlike the outdoor air, can be modified; thus strategies can emphasize reduction of pollutant exposure in the patient's home. Importantly, recent evidence from our research group shows that increased indoor air pollutant concentrations (particulate matter (PM) and nitrogen dioxide (NO2)) in homes of formers smokers with COPD are associated with respiratory morbidity, including increased respiratory symptoms, worse quality of life and increased risk of exacerbations and health care utilization. Our group has shown that home interventions that use portable air cleaners with HEPA filters successfully reduce PM concentrations and an additional carbon filter in the air cleaner may reduce NO2 concentrations. We have also shown that air cleaner intervention strategies improve respiratory symptoms in other chronic respiratory diseases, including in children with asthma, however it remains unclear whether it will work for adults with COPD. Similar studies of the efficacy of placement of portable air cleaners in homes of individuals with COPD to reduce in indoor pollutants and improve COPD health have not been conducted. In order to bridge this gap from epidemiologic evidence to research that can inform clinical practice, we propose a home intervention study to test whether targeted reductions of indoor pollutant concentrations in homes of former smokers with COPD will improve respiratory health. These aims will be accomplished using a randomized controlled trial (n=120), with 60 former smokers with COPD in each group receiving either placement of HEPA and carbon filter air cleaners or sham air cleaners in homes. We aim to determine whether an air cleaner intervention will improve respiratory symptoms, quality of life, lung function and reduce risk of exacerbations (Specific Aim #1); and whether it will be associated with intermediate outcome measures known to be linked with long term outcomes in COPD, including airway (induced sputum) and systemic (serum and urine) markers of inflammation and oxidative stress (Specific Aim #2). Our study aims build upon a well- established infrastructure of investigators with complementary areas of expertise. We anticipate that results from this study will inform clinical practice guidelines and health care policies aimed at reducing COPD morbidity. With COPD being the third leading cause of death in the US, developing strategies to reduce morbidity is an important public health priority.