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

描述(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展性疾病。戒烟可以减缓疾病的进展；然而，并不是所有的人都能从戒烟中受益，尽管戒烟，但许多人仍然患有呼吸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，避免加剧疾病的因素。虽然室外空气污染对COPD发病率和死亡率有已知的不利影响，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，而且在个人层面上，室内空气与室外空气不同，可以进行修改；因此，策略可以强调减少患者家中的污染物暴露。重要的是，我们研究小组最近的证据表明，患有COPD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))增加与呼吸道发病率有关，包括呼吸道症状增加、生活质量下降、病情恶化的风险和医疗保健利用率增加。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可以成功地降低PM浓度，并且在空气净化器中增加一个碳过滤器可能会降低NO2浓度。我们还表明，空气净化器干预策略改善了其他慢性呼吸道疾病的呼吸道症状，包括患有哮喘的儿童，但尚不清楚它是否适用于患有COPD的成年人。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健康的效果还没有进行过类似的研究。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的这一差距，我们提出了一项家庭干预研究，以测试有针对性地降低患有COPD的前吸烟者家中的室内污染物浓度是否会改善呼吸健康。这些目标将通过随机对照试验来实现(n=120)，每组60名患有COPD的前吸烟者要么接受HEPA和碳过滤器空气过滤器，要么在家里安装假空气过滤器。我们的目标是确定空气净化器干预是否将改善呼吸道症状、生活质量、肺功能并降低病情恶化的风险(具体目标1)；以及它是否与已知与慢性阻塞性肺疾病长期结果有关的中期结果措施有关，包括呼吸道(诱导痰)和全身(血清和尿液)炎症和氧化应激标志(具体目标2)。我们的研究旨在建立一个完善的基础设施，由具有互补专业知识的调查人员组成。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参考。由于慢性阻塞性肺病是美国第三大死因，制定降低发病率的策略是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.