美国哥伦比亚大学医学中心R. Graham Barr团队分析了老年人气道发育不协调与慢性阻塞性肺病的相关性。2020年6月9日，相关论文发表在《美国医学会杂志》上。

吸烟是慢性阻塞性肺病（COPD）的主要危险因素，但很多COPD风险仍无法解释。

为了确定气道发育不协调（通过CT评估的气道树径与肺部大小不匹配）是否与老年人中发生的COPD以及COPD肺功能下降有关，研究组在美国和加拿大进行了一项基于2个社区样本的回顾性队列研究。主要结果为COPD，定义为支气管扩张后一秒用力呼气量与肺活量之比（FEV1:FVC）小于0.70，且伴有呼吸症状。次要结果为纵向肺功能。

在MESA队列中，2531名动脉粥样硬化患者的平均年龄为69岁，女性占52.7%，其中有237名（9.4%）患COPD，气道与肺的平均比率为0.033，FEV1平均下降33 mL/y。在2294名未患COPD的参与者中，中位6.2年间有98名（4.3%）发生COPD。气道-肺部比率最低四分位数的参与者COPD发生率显著高于最高四分位数的参与者，分别为每1000人年9.8例和1.2例；但FEV1下降无显著差异，分别下降31和33 mL/y。

在CanCOLD队列中，1272名阻塞性肺病参与者的平均年龄为67岁，其中女性占44.3%。中位3.1年间，752名患者中有113名（15.0％）发生COPD，FEV1平均下降36 mL/y。气道-肺部比率最低四分位数的参与者COPD发生率显著高于最高四分位数的参与者，分别为每1000人年80.6例和24.2例，但FEV1下降并没有显著差异，分别为34和36 mL/y。

在SPIROMICS队列中，接受中位随访2.1年的1206名参与者的平均年龄为65岁，女性占44.9%，气道-肺部比率最低四分位数的参与者平均FEV1下降了37 mL/y，与MESA参与者相比无显著差异，但最高四分位数的参与者下降了55 mL/y，显著快于MESA参与者。

总之，在老年人中，气道发育不协调与COPD显著相关，相对于肺部大小而言，气道树径越小，COPD风险越大。

附：英文原文

Title: Association of Dysanapsis With Chronic Obstructive Pulmonary Disease Among Older Adults

Author: Benjamin M. Smith, Miranda Kirby, Eric A. Hoffman, Richard A. Kronmal, Shawn D. Aaron, Norrina B. Allen, Alain Bertoni, Harvey O. Coxson, Chris Cooper, David J. Couper, Gerard Criner, Mark T. Dransfield, MeiLan K. Han, Nadia N. Hansel, David R. Jacobs, Joel D. Kaufman, Ching-Long Lin, Ani Manichaikul, Fernando J. Martinez, Erin D. Michos, Elizabeth C. Oelsner, Robert Paine, Karol E. Watson, Andrea Benedetti, Wan C. Tan, Jean Bourbeau, Prescott G. Woodruff, R. Graham Barr

Issue&Volume: 2020/06/09

Abstract: Importance  Smoking is a major risk factor for chronic obstructive pulmonary disease (COPD), yet much of COPD risk remains unexplained.

Objective  To determine whether dysanapsis, a mismatch of airway tree caliber to lung size, assessed by computed tomography (CT), is associated with incident COPD among older adults and lung function decline in COPD.

Design, Setting, and Participants  A retrospective cohort study of 2 community-based samples: the Multi-Ethnic Study of Atherosclerosis (MESA) Lung Study, which involved 2531 participants (6 US sites, 2010-2018) and the Canadian Cohort of Obstructive Lung Disease (CanCOLD), which involved 1272 participants (9 Canadian sites, 2010-2018), and a case-control study of COPD: the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS), which involved 2726 participants (12 US sites, 2011-2016).

Exposures  Dysanapsis was quantified on CT as the geometric mean of airway lumen diameters measured at 19 standard anatomic locations divided by the cube root of lung volume (airway to lung ratio).

Main Outcomes and Measures  Primary outcome was COPD defined by postbronchodilator ratio of forced expired volume in the first second to vital capacity (FEV1:FVC) less than 0.70 with respiratory symptoms. Secondary outcome was longitudinal lung function. All analyses were adjusted for demographics and standard COPD risk factors (primary and secondhand tobacco smoke exposures, occupational and environmental pollutants, and asthma).

Results  In the MESA Lung sample (mean [SD] age, 69 years [9 years]; 1334 women [52.7%]), 237 of 2531 participants (9.4%) had prevalent COPD, the mean (SD) airway to lung ratio was 0.033 (0.004), and the mean (SD) FEV1 decline was 33 mL/y (31 mL/y). Of 2294 MESA Lung participants without prevalent COPD, 98 (4.3%) had incident COPD at a median of 6.2 years. Compared with participants in the highest quartile of airway to lung ratio, those in the lowest had a significantly higher COPD incidence (9.8 vs 1.2 cases per 1000 person-years; rate ratio [RR], 8.12; 95% CI, 3.81 to 17.27; rate difference, 8.6 cases per 1000 person-years; 95% CI, 7.1 to 9.2; P<.001) but no significant difference in FEV1 decline (31 vs 33 mL/y; difference, 2 mL/y; 95% CI, 2 to 5; P=.30). Among CanCOLD participants (mean [SD] age, 67 years [10 years]; 564 women [44.3%]), 113 of 752 (15.0%) had incident COPD at a median of 3.1 years and the mean (SD) FEV1 decline was 36 mL/y (75 mL/y). The COPD incidence in the lowest airway to lung quartile was significantly higher than in the highest quartile (80.6 vs 24.2 cases per 1000 person-years; RR, 3.33; 95% CI, 1.89 to 5.85; rate difference, 56.4 cases per 1000 person-years; 95% CI, 38.0 to 66.8; P<.001), but the FEV1 decline did not differ significantly (34 vs 36 mL/y; difference, 1 mL/y; 95% CI, 15 to 16; P=.97). Among 1206 SPIROMICS participants (mean [SD] age, 65 years [8 years]; 542 women [44.9%]) with COPD who were followed up for a median 2.1 years, those in the lowest airway to lung ratio quartile had a mean FEV1 decline of 37 mL/y (15 mL/y), which did not differ significantly from the decline in MESA Lung participants (P=.98), whereas those in highest quartile had significantly faster decline than participants in MESA Lung (55 mL/y [16 mL/y ]; difference, 17 mL/y; 95% CI, 32 to 3; P=.004).

Conclusions and Relevance  Among older adults, dysanapsis was significantly associated with COPD, with lower airway tree caliber relative to lung size associated with greater COPD risk. Dysanapsis appears to be a risk factor associated with COPD.

DOI: 10.1001/jama.2020.6918

Source: https://jamanetwork.com/journals/jama/article-abstract/2766866