Prevalence and risk factors of small airway dysfunction, and association with smoking, in China: findings from a national cross-sectional study.
影响因子： 25.094 PMID： 32598906 期刊年卷： Lancet Respir Med 2020 11;8(11) DOI： 10.1016/S2213-2600(20)30155-7 作者列表: Xiao D, Chen Z, Wu S, ……
BACKGROUND:Small airway dysfunction is a common but neglected respiratory abnormality. Little is known about its prevalence, risk factors, and prognostic factors in China or anywhere else in the world. We aimed to estimate the prevalence of small airway dysfunction using spirometry before and after bronchodilation, both overall and in specific population subgroups; assess its association with a range of lifestyle and environmental factors (particularly smoking); and estimate the burden of small airway dysfunction in China.
METHODS:From June, 2012, to May, 2015, the nationally representative China Pulmonary Health study invited 57 779 adults to participate using a multistage stratified sampling method from ten provinces (or equivalent), and 50 479 patients with valid lung function testing results were included in the analysis. We diagnosed small airway dysfunction on the basis of at least two of the following three indicators of lung function being less than 65% of predicted: maximal mid-expiratory flow, forced expiratory flow (FEF) 50%, and FEF 75%. Small airway dysfunction was further categorised into pre-small airway dysfunction (defined as having normal FEV and FEV/forced vital capacity [FVC] ratio before bronchodilator inhalation), and post-small airway dysfunction (defined as having normal FEV and FEV/FVC ratio both before and after bronchodilator inhalation). Logistic regression yielded adjusted odds ratios (ORs) for small airway dysfunction associated with smoking and other lifestyle and environmental factors. We further estimated the total number of cases of small airway dysfunction in China by applying present study findings to national census data.
FINDINGS:Overall the prevalence of small airway dysfunction was 43·5% (95% CI 40·7-46·3), pre-small airway dysfunction was 25·5% (23·6-27·5), and post-small airway dysfunction was 11·3% (10·3-12·5). After multifactor regression analysis, the risk of small airway dysfunction was significantly associated with age, gender, urbanisation, education level, cigarette smoking, passive smoking, biomass use, exposure to high particulate matter with a diameter less than 2·5 μm (PM) concentrations, history of chronic cough during childhood, history of childhood pneumonia or bronchitis, parental history of respiratory diseases, and increase of body-mass index (BMI) by 5 kg/m. The ORs for small airway dysfunction and pre-small airway dysfunction were similar, whereas larger effect sizes were generally seen for post-small airway dysfunction than for either small airway dysfunction or pre-small airway dysfunction. For post-small airway dysfunction, cigarette smoking, exposure to PM, and increase of BMI by 5 kg/m were significantly associated with increased risk, among preventable risk factors. There was also a dose-response association between cigarette smoking and post-small airway dysfunction among men, but not among women. We estimate that, in 2015, 426 (95% CI 411-468) million adults had small airway dysfunction, 253 (238-278) million had pre-small airway dysfunction, and 111 (104-126) million had post-small airway dysfunction in China.
INTERPRETATION:In China, spirometry-defined small airway dysfunction is highly prevalent, with cigarette smoking being a major modifiable risk factor, along with PM exposure and increase of BMI by 5 kg/m. Our findings emphasise the urgent need to develop and implement effective primary and secondary prevention strategies to reduce the burden of this condition in the general population.
中国小气道功能障碍的患病率和危险因素，以及与吸烟的关系:一项全国性横断面研究的发现
背景:小气道功能障碍是一种常见但被忽视的呼吸异常。目前对其在中国或世界其他地方的患病率、风险因素和预后因素知之甚少。我们的目的是评估小气道功能障碍的患病率，使用肺量测定前和后的支气管舒张，包括整体和特定人群亚组;评估其与一系列生活方式和环境因素(特别是吸烟)的关系;并评估我国小气道功能障碍的负担。
方法:2012年6月至2015年5月，在全国具有代表性的《中国肺健康》研究中，采用多阶段分层抽样的方法，从10个省(或同等)邀请57 779名成人参与研究，纳入50 479例肺功能检测结果有效的患者进行分析。我们诊断小气道功能障碍的基础是肺功能以下三个指标中至少两个小于预测值的65%:最大呼气中期流量、用力呼气流量(FEF) 50%和FEF 75%。进一步将小气道功能障碍分为前小气道功能障碍(吸入支气管扩张剂前、后FEV和FEV/FVC比值均正常)和后小气道功能障碍(吸入支气管扩张剂前后FEV和FEV/FVC比值均正常)。Logistic回归得出了与吸烟、其他生活方式和环境因素相关的小气道功能障碍的校正优势比(ORs)。我们将本研究结果应用于全国人口普查数据，进一步估算我国小气道功能障碍病例总数。
结果:小气道功能障碍发生率为43.5 % (95% CI 40·7 ~ 46·3)，前小气道功能障碍发生率为25·5%(23·6 ~ 27·5)，后小气道功能障碍发生率为11·3%(10·3 ~ 12·5)。经多因素回归分析，小气道功能障碍的风险与年龄、性别、城市化程度、文化程度、吸烟、被动吸烟、生物质利用、暴露于直径小于2.5 μm的高颗粒物(PM)、儿童期慢性咳嗽史、儿童肺炎或支气管炎史，父母有呼吸道疾病史，体重指数(BMI)增加5kg /m。小气道功能障碍和小气道前功能障碍的or相似，但小气道后功能障碍的效应量通常大于小气道功能障碍和小气道前功能障碍。对于小气道功能障碍后，在可预防的危险因素中，吸烟、暴露于PM和BMI增加5 kg/m与风险增加显著相关。在男性中，吸烟和小气道后功能障碍之间也存在剂量反应关系，但在女性中没有。我们估计，2015年，中国有426万人(95% CI 411- 4.68)患有小气道功能障碍，253万人(238- 2.78)患有小气道功能障碍，111万人(104- 1.26)患有小气道功能障碍。
解释:在中国，肺气量测定定义的小气道功能障碍非常普遍，吸烟是一个主要的可改变的危险因素，与PM暴露和BMI增加5公斤/米。我们的研究结果强调了迫切需要制定和实施有效的一级和二级预防策略，以减少一般人群中的这一疾病负担。