title: Prevalence and correlates of pulmonary emphysema in smokers and former smokers. A densitometric study of participants in the ITALUNG trial.
abstract: We assessed with computed tomography (CT) densitometry the prevalence of emphysema in 266 (175 men and 91 women; mean age 64 +/- 4 years) smokers and former smokers enrolled in the ITALUNG trial of lung cancer screening with low-dose thin-slice CT. Whole-lung volume and the relative area at -950 Hounsfield units (RA(950)) and mean lung attenuation (MLA) in 1 of every 10 slices (mean, 24 slices per subject) were measured. Lung volume, MLA and RA950 significantly correlated each other and with age. Average RA950 >6.8% qualifying for emphysema was present in 71 (26.6%) of 266 subjects, with a higher prevalence in men than in women (30.3% vs 19.8%; p = 0.003). Only in smokers was a weak (r = 0.18; p = 0.05) correlation between RA950 and packs/year observed. In multiple regression analysis, the variability of RA950 (R2 = 0.24) or MLA (R2 = 0.34) was significantly, but weakly explained by age, lung volume and packs/year. Other factors besides smoking may also have a significant role in the etiopathogenesis of pulmonary emphysema.
authors.affiliation: Dipartimento Area Critica, Università di Firenze, Firenze, Italy.
authors.forename: Gianna
authors.initials: G
authors.lastname: Camiciottoli
authors.forename: Edoardo
authors.initials: E
authors.lastname: Cavigli
authors.forename: Luca
authors.initials: L
authors.lastname: Grassi
authors.forename: Stefano
authors.initials: S
authors.lastname: Diciotti
authors.forename: Ilaria
authors.initials: I
authors.lastname: Orlandi
authors.forename: Marco
authors.initials: M
authors.lastname: Zappa
authors.forename: Giulia
authors.initials: G
authors.lastname: Picozzi
authors.forename: Andrea Lopes
authors.initials: AL
authors.lastname: Pegna
authors.forename: Eugenio
authors.initials: E
authors.lastname: Paci
authors.forename: Fabio
authors.initials: F
authors.lastname: Falaschi
authors.forename: Mario
authors.initials: M
authors.lastname: Mascalchi
mesh_terms: D015502:Absorptiometry, Photon / Q000706:statistics & numerical data*; D015984:Causality; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology*; D016540:Smoking Cessation / Q000706:statistics & numerical data*; D013223:Statistics as Topic; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*