@article {Shaker1883, author = {Saher B. Shaker and Asger Dirksen and Pechin Lo and Lene T. Skovgaard and Marleen de Bruijne and Jesper H. Pedersen}, title = {Decline in lung density is accelerated in active smokers}, volume = {38}, number = {Suppl 55}, elocation-id = {1883}, year = {2011}, publisher = {European Respiratory Society}, abstract = {Background: Emphysema is associated with rapid decline in lung density; however, this decline may be influenced by other factors including smoking habits.Objective: To compare the annual decline in lung density between current and ex-smokers with or without airflow obstruction (AFO).Material and methods: As part of the Danish Lung Cancer Screening Trial, 2,052 current or ex-smokers aged 50-70 years were screened annually for 5 years (2005-2009) with low dose CT. At annual screening rounds, smoking habits were recorded; carbon monoxide level in exhaled breath was measured; and spirometry was performed. CT lung density was measured as the volume-adjusted 15th percentile density (PD15). The influence of sex, age, smoking and AFO on PD15 was analysed in a mixed effects model with random intercept and random slope of time effect. Former smoking men with less than 30 pack-years and with no AFO at entry were chosen as reference group.Results: Data were analysed for all subjects throughout the study although censored after they changed their smoking habit. At study entry, 1075 subjects did not have AFO and 843 subjects had AFO based on GOLD spirometry criteria. For the reference group, PD15 was (mean{\textpm}SE) 72.4{\textpm}0.8 g/L, and was higher in women (17.0{\textpm}0.6 g/L); and in active smokers (10.5{\textpm}0.7 g/L); and lower in subjects with AFO ({\textendash}3.4{\textpm}0.6 g/L). Annual decline in PD15 for the reference group was {\textendash}0.38{\textpm}0.08 g/L/yr and was higher in women, with additional (0.30{\textpm}0.07 g/L/yr), current smokers with additional (0.53{\textpm}0.08 g/L/yr) and for subjects with AFO with additional (0.34{\textpm}0.07 g/L/yr).Conclusion: Active smoking, female sex and the presence of airflow obstruction are associated with accelerated decline in lung density.}, issn = {0903-1936}, URL = {https://erj.ersjournals.com/content/38/Suppl_55/1883}, eprint = {https://erj.ersjournals.com/content}, journal = {European Respiratory Journal} }