Association Between Expiratory Central Airway Collapse and Respiratory Outcomes Among Smokers
- PMID: 26836732
- PMCID: PMC5173387
- DOI: 10.1001/jama.2015.19431
Association Between Expiratory Central Airway Collapse and Respiratory Outcomes Among Smokers
Abstract
Importance: Central airway collapse greater than 50% of luminal area during exhalation (expiratory central airway collapse [ECAC]) is associated with cigarette smoking and chronic obstructive pulmonary disease (COPD). However, its prevalence and clinical significance are unknown.
Objective: To determine whether ECAC is associated with respiratory morbidity in smokers independent of underlying lung disease.
Design, setting, and participants: Analysis of paired inspiratory-expiratory computed tomography images from a large multicenter study (COPDGene) of current and former smokers from 21 clinical centers across the United States. Participants were enrolled from January 2008 to June 2011 and followed up longitudinally until October 2014. Images were initially screened using a quantitative method to detect at least a 30% reduction in minor axis tracheal diameter from inspiration to end-expiration. From this sample of screen-positive scans, cross-sectional area of the trachea was measured manually at 3 predetermined levels (aortic arch, carina, and bronchus intermedius) to confirm ECAC (>50% reduction in cross-sectional area).
Exposures: Expiratory central airway collapse.
Main outcomes and measures: The primary outcome was baseline respiratory quality of life (St George's Respiratory Questionnaire [SGRQ] scale 0 to 100; 100 represents worst health status; minimum clinically important difference [MCID], 4 units). Secondary outcomes were baseline measures of dyspnea (modified Medical Research Council [mMRC] scale 0 to 4; 4 represents worse dyspnea; MCID, 0.7 units), baseline 6-minute walk distance (MCID, 30 m), and exacerbation frequency (events per 100 person-years) on longitudinal follow-up.
Results: The study included 8820 participants with and without COPD (mean age, 59.7 [SD, 6.9] years; 4667 [56.7%] men; 4559 [51.7%] active smokers). The prevalence of ECAC was 5% (443 cases). Patients with ECAC compared with those without ECAC had worse SGRQ scores (30.9 vs 26.5 units; P < .001; absolute difference, 4.4 [95% CI, 2.2-6.6]) and mMRC scale scores (median, 2 [interquartile range [IQR], 0-3]) vs 1 [IQR, 0-3]; P < .001]), but no significant difference in 6-minute walk distance (399 vs 417 m; absolute difference, 18 m [95% CI, 6-30]; P = .30), after adjustment for age, sex, race, body mass index, forced expiratory volume in the first second, pack-years of smoking, and emphysema. On follow-up (median, 4.3 [IQR, 3.2-4.9] years), participants with ECAC had increased frequency of total exacerbations (58 vs 35 events per 100 person-years; incidence rate ratio [IRR], 1.49 [95% CI, 1.29-1.72]; P < .001) and severe exacerbations requiring hospitalization (17 vs 10 events per 100 person-years; IRR, 1.83 [95% CI, 1.51-2.21]; P < .001).
Conclusions and relevance: In a cross-sectional analysis of current and former smokers, the presence of ECAC was associated with worse respiratory quality of life. Further studies are needed to assess long-term associations with clinical outcomes.
Conflict of interest statement
Dr. Terry, Dr. Nath and Mr. Zach have no conflicts of interest. Dr. Tschirren is an employee and shareholder at VIDA Diagnostics. Dr. Bolding, Mr. Stinson, Ms. Wilson, Dr. Everett, Dr. Putcha and Dr. Soler have no conflicts of interest.
Figures
![Figure 1](https://cdn.statically.io/img/www.ncbi.nlm.nih.gov/pmc/articles/instance/5173387/bin/nihms834152f1.gif)
Similar articles
-
Paratracheal Paraseptal Emphysema and Expiratory Central Airway Collapse in Smokers.Ann Am Thorac Soc. 2018 Apr;15(4):479-484. doi: 10.1513/AnnalsATS.201709-713OC. Ann Am Thorac Soc. 2018. PMID: 29298081 Free PMC article.
-
Association of Long-term Ambient Ozone Exposure With Respiratory Morbidity in Smokers.JAMA Intern Med. 2020 Jan 1;180(1):106-115. doi: 10.1001/jamainternmed.2019.5498. JAMA Intern Med. 2020. PMID: 31816012 Free PMC article.
-
Expiratory central airway collapse in stable COPD and during exacerbations.Respir Res. 2017 Aug 25;18(1):163. doi: 10.1186/s12931-017-0646-2. Respir Res. 2017. PMID: 28841915 Free PMC article.
-
Quantitative computed tomography measurements to evaluate airway disease in chronic obstructive pulmonary disease: Relationship to physiological measurements, clinical index and visual assessment of airway disease.Eur J Radiol. 2016 Nov;85(11):2144-2151. doi: 10.1016/j.ejrad.2016.09.010. Epub 2016 Sep 13. Eur J Radiol. 2016. PMID: 27776670 Free PMC article. Review.
-
Umeclidinium bromide versus placebo for people with chronic obstructive pulmonary disease (COPD).Cochrane Database Syst Rev. 2017 Jun 20;6(6):CD011897. doi: 10.1002/14651858.CD011897.pub2. Cochrane Database Syst Rev. 2017. PMID: 28631387 Free PMC article. Review.
Cited by
-
Tracheobronchomalacia: an unusual cause of debilitating dyspnoea and its surgical management.BMJ Case Rep. 2023 Nov 17;16(11):e254229. doi: 10.1136/bcr-2022-254229. BMJ Case Rep. 2023. PMID: 37977838
-
The utility of quantitative computed tomography in cohort studies of chronic obstructive pulmonary disease: a narrative review.J Thorac Dis. 2023 Oct 31;15(10):5784-5800. doi: 10.21037/jtd-23-1421. Epub 2023 Oct 27. J Thorac Dis. 2023. PMID: 37969311 Free PMC article. Review.
-
Gender differences in association between expiratory dynamic airway collapse and severity of obstructive sleep apnea.Eur Radiol. 2024 Jun;34(6):3730-3741. doi: 10.1007/s00330-023-10322-x. Epub 2023 Nov 14. Eur Radiol. 2024. PMID: 37962598 Free PMC article.
-
Phenotypes, Etiotypes, and Endotypes of Exacerbations of Chronic Obstructive Pulmonary Disease.Am J Respir Crit Care Med. 2023 Nov 15;208(10):1026-1041. doi: 10.1164/rccm.202209-1748SO. Am J Respir Crit Care Med. 2023. PMID: 37560988 Review.
-
Sex matters: the frequently overlooked importance of considering sex in computational models.Front Physiol. 2023 Jul 13;14:1186646. doi: 10.3389/fphys.2023.1186646. eCollection 2023. Front Physiol. 2023. PMID: 37520817 Free PMC article. Review.
References
-
- Murgu S, Colt H. Tracheobronchomalacia and excessive dynamic airway collapse. Clin Chest Med. 2013;34(3):527–555. - PubMed
-
- Jokinen K, Palva T, Sutinen S, Nuutinen J. Acquired tracheobronchomalacia. Ann Clin Res. 1977;9(2):52–57. - PubMed
-
- Kandaswamy C, Balasubramanian V. Review of adult tracheomalacia and its relationship with chronic obstructive pulmonary disease. Curr Opin Pulm Med. 2009;15(2):113–119. - PubMed
-
- Sverzellati N, Rastelli A, Chetta A, et al. Airway malacia in chronic obstructive pulmonary disease: prevalence, morphology and relationship with emphysema, bronchiectasis and bronchial wall thickening. Eur Radiol. 2009;19(7):1669–1678. - PubMed
-
- Hogg JC, Macklem PT, Thurlbeck WM. Site and nature of airway obstruction in chronic obstructive lung disease. N Engl J Med. 1968;278(25):1355–1360. - PubMed
Publication types
MeSH terms
Grants and funding
LinkOut - more resources
Full Text Sources
Other Literature Sources
Medical