Rate of progression of CT-quantified emphysema in male current and ex-smokers: a follow-up study

BACKGROUND: Little is known about the factors associated with CT-quantified emphysema progression in heavy smokers. The objective of this study was to investigate the effect of length of smoking cessation and clinical / demographical factors on the rate of emphysema progression and FEV1-decline in male heavy smokers. METHODS: 3,670 male smokers with mean (SD) 40.8 (17.9) packyears underwent chest CT scans and pulmonary function tests at baseline and after 1 and 3 years follow-up. Smoking status (quitted >=5, >=1-=5 group was used as reference. RESULTS: Median (Q1-Q3) emphysema severity,5 years' showed significantly lower rates of progression of emphysema compared to current smokers, 1.07\% and 1.12\% per year, respectively (p5 years had a yearly decline of 57.5 ml (p5 years significantly slows the rate of emphysema progression and lung function decline.Trial registration: Registered at www.trialregister.nl with trial number ISRCTN63545820