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. 2013 Apr 16;8(4):e61783.
doi: 10.1371/journal.pone.0061783. Print 2013.

CT air trapping is independently associated with lung function reduction over time

Onno M Mets  1 , Pim A de Jong, Bram van Ginneken, Cas L J J Kruitwagen, Mathias Prokop, Matthijs Oudkerk, Jan-Willem J Lammers, Pieter Zanen
Affiliations

CT air trapping is independently associated with lung function reduction over time

Onno M Mets et al. PLoS One. .

Abstract

Purpose: We aimed to study the association between lung function decline and quantitative computed tomography (CT) air trapping.

Materials and methods: Current and former heavy smokers in a lung cancer screening trial underwent volumetric low-dose CT in inspiration and expiration. Spirometry was obtained at baseline and after 3 years. The expiratory to inspiratory ratio of mean lung density (E/I-ratioMLD) was used to quantify air trapping. CT emphysema was defined as voxels in inspiratory CT below -950 Hounsfield Unit. Linear mixed modeling was used to determine the association between CT air trapping and lung function.

Results: We included 985 subjects with a mean age of 61.3 years. Independent of CT emphysema, CT air trapping was significantly associated with a reduction in forced expiratory volume in one second (FEV1) and the ratio of FEV1 over the forced vital capacity (FEV1/FVC); FEV1 declines with 33 mL per percent increase in CT air trapping, while FEV1/FVC declines 0.58% per percent increase (both p<0.001). CT air trapping further elicits accelerated loss of FEV1/FVC (additional 0.24% reduction per percent increase; p = 0.014).

Conclusion: In a lung cancer screening cohort, quantitatively assessed air trapping on low-dose CT is independently associated with reduced lung function and accelerated decline of FEV1/FVC.

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Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1
Figure 1. The effect of increase in CT air trapping extent on FEV1.
The effect of increasing extent of CT air trapping (25th percentile, stars; 50th percentile, squares; 75th percentile, triangles) on FEV1 is shown in a current (left panel) and former smoker (right panel) with fixed values for age/length/packyears (mean of the study population) and CT emphysema (median of the study population). It is seen that more extensive CT air trapping leads to a reduction in FEV1.
Figure 2
Figure 2. The effect of increase in CT air trapping extent on FEV1/FVC.
The effect of increasing extent of CT air trapping (25th percentile, star; 50th percentile, square; 75th percentile, triangle) on FEV1/FVC is shown in a current (left panel) and former smoker (right panel) with fixed values for age/length/packyears (mean of the study population) and CT emphysema (median of the study population). It is seen that more extensive CT air trapping leads to a reduction in FEV1/FVC, and the diverging course illustrates the association between CT air trapping and accelerated decline.
See this image and copyright information in PMC

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References

    1. Mathers CD, Loncar D (2006) Projections of global mortality and burden of disease from 2002 to 2030. PLoS Med 3(11): e442. - PMC - PubMed
    1. Murray CJ, Lopez AD (1997) Alternative projections of mortality and disability by cause 1990–2020: Global Burden of Disease Study. Lancet 349(9064): 1498–1504. - PubMed
    1. Rabe KF, Hurd S, Anzueto A, Barnes PJ, Buist SA, et al. (2007) Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: GOLD executive summary. Am J Respir Crit Care Med 176(6): 532–555. - PubMed
    1. Fletcher C, Peto R (1977) The natural history of chronic airflow obstruction. Br Med J 1(6077): 1645–1648. - PMC - PubMed
    1. Fiore MC, Baker TB (2011) Clinical practice. Treating smokers in the health care setting. N Engl J Med 365(13): 1222–1231. - PMC - PubMed

Publication types

Grants and funding

The NELSON-trial was sponsored by: Netherlands Organisation for Health Research and Development (ZonMw); Dutch Cancer Society Koningin Wilhelmina Fonds (KWF); Stichting Centraal Fonds Reserves van Voormalig Vrijwillige Ziekenfondsverzekeringen (RvvZ); Siemens Germany; Roche Diagnostics; Rotterdam Oncologic Thoracic Steering committee (ROTS); G.Ph.Verhagen Trust, Flemish League Against Cancer, Foundation Against Cancer and Erasmus Trust Fund. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.