Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
Section of Occupational and Environmental Medicine, School of Public Health and Community Medicine.
Ann Am Thorac Soc. 2024 Dec;21(12):1678-1687. doi: 10.1513/AnnalsATS.202402-122OC.
Chronic obstructive pulmonary disease (COPD) includes respiratory symptoms and chronic airflow limitation (CAL). In some cases, emphysema and impaired diffusing capacity of the lung for carbon monoxide (Dl) are present, but characteristics and symptoms vary with smoking exposure. To study the prevalence of CAL, emphysema, and impaired Dl in relation to smoking and respiratory symptoms in a middle-aged population. We investigated 28,746 randomly invited individuals (52% women) aged 50-64 years across six Swedish sites. We performed spirometry, Dl testing, and high-resolution computed tomography and asked for smoking habits and respiratory symptoms. CAL was defined as post-bronchodilator forced expiratory volume in 1 second divided by forced vital capacity (FEV/FVC) < 0.7. The overall prevalence was 8.8% for CAL, 5.7% for impaired Dl (Dl < LLN), and 8.8% for emphysema, with a higher prevalence in current smokers than in ex-smokers and never-smokers. The proportion of never-smokers among those with CAL, emphysema, and impaired Dl was 32%, 19%, and 31%, respectively. Regardless of smoking habits, the prevalence of respiratory symptoms was higher among people with CAL and impaired Dl than those with normal lung function. Asthma prevalence in never-smokers with CAL was 14%. In this group, asthma was associated with lower FEV and more respiratory symptoms. In this large population-based study of middle-aged people, CAL and impaired Dl were associated with common respiratory symptoms. Self-reported asthma was not associated with CAL in never-smokers. Our findings suggest that CAL in never-smokers signifies a separate clinical phenotype that may be monitored and, possibly, treated differently from smoking-related COPD.
慢性阻塞性肺疾病（COPD）包括呼吸系统症状和慢性气流受限（CAL）。在某些情况下，还存在肺气肿和一氧化碳弥散量降低（Dl），但特征和症状因吸烟暴露而异。 为了研究吸烟与呼吸系统症状相关的中年人群中 CAL、肺气肿和 Dl 降低的患病率。我们调查了六个瑞典地点随机邀请的 28746 名（52%为女性）年龄在 50-64 岁的个体。我们进行了肺活量测定、Dl 测试和高分辨率计算机断层扫描，并询问了吸烟习惯和呼吸系统症状。CAL 定义为支气管扩张剂后 1 秒用力呼气量与用力肺活量（FEV/FVC）之比<0.7。CAL 的总体患病率为 8.8%，Dl 降低（Dl<LLN）为 5.7%，肺气肿为 8.8%，当前吸烟者的患病率高于戒烟者和从不吸烟者。CAL、肺气肿和 Dl 患者中从不吸烟者的比例分别为 32%、19%和 31%。无论吸烟习惯如何，CAL 和 Dl 降低的患者呼吸系统症状的患病率均高于肺功能正常者。CAL 患者中从不吸烟者的哮喘患病率为 14%。在这组人群中，哮喘与较低的 FEV 和更多的呼吸系统症状相关。在这项针对中年人群的大型基于人群的研究中，CAL 和 Dl 降低与常见的呼吸系统症状相关。在从不吸烟者中，CAL 与哮喘无相关性。我们的研究结果表明，从不吸烟者的 CAL 表示一种单独的临床表型，可能需要进行不同的监测和治疗，与吸烟相关的 COPD 不同。
