%0 Journal Article
%T CT Air Trapping Is Independently Associated with Lung Function Reduction over Time
%A Onno M. Mets
%A Pim A. de Jong
%A Bram van Ginneken
%A Cas L. J. J. Kruitwagen
%A Mathias Prokop
%A Matthijs Oudkerk
%A Jan-Willem J. Lammers
%A Pieter Zanen
%J PLOS ONE
%D 2013
%I Public Library of Science (PLoS)
%R 10.1371/journal.pone.0061783
%X 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.
%U http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0061783