摘要目的 探讨大气NO2对慢性阻塞性肺疾病患者肺功能和呼出气NO水平的短期影响.方法 采用定组研究的设计,在北京招募稳定期慢性阻塞性肺疾病患者,纳入标准为在北京居住时间超过1年,年龄在60~85岁之间的患者,排除患有哮喘、支气管扩张、肺癌等除慢阻肺以外的其他呼吸系统疾病以及有职业暴露和胸部创伤手术史的患者,共招募研究对象33例.于2013年12月至2014年10月期间,对患者肺功能和呼出气NO进行重复测量,由于研究对象到医院就诊的频次不同,本研究共采集患者肺功能数据170人次,采集呼出气NO数据215人次.同时收集测量前累积滞后(lag)1 d至7 d研究对象住所附近的北京市环境监测站点大气NO2数据;采用线性混合效应模型评价大气NO2对研究对象肺功能和呼出气NO的短期影响.结果 研究对象的用力肺活量(FVC)、第一秒用力呼气肺容量(FEV1)、最大呼气峰流速(PEF)及呼出气NO值分别为(3.26±0.83)L、(1.66±0.61)L、(4.13±1.77)L/s和(48.99±14.30)μg/m3.大气NO2暴露浓度为(70.3±34.2)μg/m3,四分位数间距(IQR)为39.0μg/m3.大气NO2短期暴露可引起患者FVC水平的下降,其效应在lag 2 d时最大,大气NO2浓度每增加一个IQR(39μg/m3),可引起研究对象FVC水平下降1.84%(95%CI:-3.20%~-0.48%);分层分析发现,较高浓度大气NO2(≥58.0μg/m3)暴露对FVC影响的效应估计值为-2.32%(95%CI:-4.15%~-0.48%);本研究未发现大气NO2对患者呼出气NO水平有影响.结论 大气NO2短期暴露可使慢性阻塞性肺疾病患者肺功能降低.

abstractsObjectives To investigate the effect of short-term exposure to ambient NO2 has influence on lung function and fractional exhaled nitric oxide (FeNO) in chronic obstructive pulmonary disease (COPD) patients. Methods A panel of doctor-diagnosed stable COPD patients (n=33) were recruited and repeatedly measured for lung function and FeNO from December 2013 to October 2014. The patients who lived in Beijing for more than one year and aged between 60 and 85 years old were included in the study. We excluded patients with asthma, bronchial tensor, lung cancer and other respiratory disorders other than chronic obstructive pulmonary disease and occupational exposure and chest trauma surgery patients. Because the frequency of each subject visiting to the hospital was different,a total of 170 times of lung function measurements and 215 times of FeNO measurements were conducted. At the same time, the atmospheric NO2 data of Beijing environmental monitoring station near the residence of each patient during the study period were collected from 1 day to 7 days lag before the measurement. Effects of short-term NO2 exposure on lung function and FeNO in COPD patients were estimated by linear mixed-effects models. Results The subjects' forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow (PEF), and exhaled NO of subjects were (3.26±0.83) L, (1.66±0.61) L, (4.13±1.77) L/s, and (48.99±14.30) μg/m3, respectively. The concentration of NO2 was (70.3±34.2) μg/m3 and the interquartile range (IQR) was 39.0 μg/m3. Short-term exposure to NO2 resulted in a significant decrease in FVC among COPD patients' which was most obvious in 2 days lag. Every quartile range increased in NO2 (39 μg/m3, 2 day) would cause a 1.84% (95%CI: -3.20%- -0.48%) reduction in FVC. The effects of exposure to higher concentration of NO2 (≥58.0 μg/m3) on FVC estimate was -2.32 % (95%CI: -4.15%- -0.48%)(P=0.02). No significant relevance of FeNO and NO2 was observed in this study. Conclusions Short term exposure to ambient NO2 may bring down pulmonary function in COPD patients.