Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2018 Oct 11;13(10):e0205273.
doi: 10.1371/journal.pone.0205273. eCollection 2018.

Quantitative computed tomography phenotypes, spirometric parameters, and episodes of exacerbation in heavy smokers: An analysis from South America

Marcelo Cardoso Barros  1 , Bruno Hochhegger  2 , Stephan Altmayer  2 , Guilherme Watte  2 , Matheus Zanon  2 , Ana Paula Sartori  2 , Daniela Cavalet Blanco  1 , Gabriel Sartori Pacini  2 , Jose Miguel Chatkin  1
Affiliations

Quantitative computed tomography phenotypes, spirometric parameters, and episodes of exacerbation in heavy smokers: An analysis from South America

Marcelo Cardoso Barros et al. PLoS One. .

Abstract

Objective: To evaluate the quantitative computed tomography (QCT) phenotypes, airflow limitations, and exacerbation-like episodes in heavy smokers in Southern Brazil.

Methods: We enrolled 172 smokers with a smoking history ≥30 pack-years who underwent pulmonary function tests (PFTs) and CT scan for lung cancer screening. Patients were classified regarding airflow limitation (FEV1/FVC <0.7 forced expiratory volume in 1 second/forced vital capacity) and the presence of emphysema on the QCT. The QCT were analyzed in specialized software and patients were classified in two disease-predominant phenotypes: emphysema-predominant (EP) and non-emphysema-predominant (NEP). EP was determined as ≥6% of percent low-attenuation areas (LAA%) with less than -950 Hounsfield units. NEP was defined as having a total LAA% of less than 6%.

Results: Most of our patients were classified in the EP phenotype. The EP group had significantly worse predicted FEV1 (60.6 ±22.9 vs. 89.7 ±15.9, p <0.001), higher rates of airflow limitation (85.7% vs. 15%; p <0.001), and had more exacerbation-like episodes (25.8% vs. 8.3%, p <0.001) compared to the NEP group. Smoking history, ethnicity, and BMI did not differ between the groups. The total LAA% was the QCT parameter with the strongest correlation to FEV1 (r = -0.669) and FEV1/FVC (r = -0.787).

Conclusions: Heavy smokers with the EP phenotype on QCT were more likely to have airflow limitation, worse predicted FEV1, and a higher rate of exacerbation-like episodes than those with the NEP phenotype. Approximately 23% of patients with no airflow limitation on PFTs were classified in EP phenotype.

PubMed Disclaimer

Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Flow diagram showing the inclusion criteria of the study population.
Fig 2
Fig 2. CT scan of a patient with FEV1/FVC = 73.4, but a total low-attenuation area of 18%.
(A) Axial CT image demonstrating areas of emphysematous changes (arrowheads). (B) Axial MINIP reconstruction of the same patient shows a predominantly diffuse pattern of low-attenuation (C) Colored reconstruction of a coronal image demonstrating multiple low-attenuation areas in blue.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. From the Global Strategy for the Diagnosis, Management and Prevention of COPD, Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017. Available from: http://goldcopd.org/.
    1. Agusti A, Vestbo J. Current controversies and future perspectives in chronic obstructive pulmonary disease. Am J Respir Crit Care Med. 2011;184(5):507–13. 10.1164/rccm.201103-0405PP - DOI - PubMed
    1. Agusti A, Calverley PM, Celli B, Coxson HO, Edwards LD, Lomas DA, et al. Characterisation of COPD heterogeneity in the ECLIPSE cohort. Respir Res. 2010;11:122 10.1186/1465-9921-11-122 - DOI - PMC - PubMed
    1. Regan EA, Lynch DA, Curran-Everett D, Curtis JL, Austin JH, Grenier PA, et al. Clinical and radiologic disease in smokers with normal spirometry. JAMA Intern Med. 2015;175(9):1539–49. 10.1001/jamainternmed.2015.2735 - DOI - PMC - PubMed
    1. Klein JS, Gamsu G, Webb WR, Golden JA, Müller NL. High-resolution CT diagnosis of emphysema in symptomatic patients with normal chest radiographs and isolated low diffusing capacity. Radiology. 1992;182(3):817–21. 10.1148/radiology.182.3.1535900 - DOI - PubMed