Low-dose CT measurements of airway dimensions and emphysema associated with airflow limitation in heavy smokers: a cross sectional study

Table 1 Clinical and demographic characteristics of heavy smokers from thegeneral population cohort

N	492
Age, years	59.4 ± 5.2
Pack-years smoking	34.0 (28.0 - 45.6)
Current smoking,%	59.1
FEV₁, liter	3.45 ± 0.76
FEV₁,%predicted	98.2 ± 19.7
FEV₁/FVC,%	70.0 ± 10.7
Emphysema; Perc15, HU	−920 (−930 to −907)
Emphysema;%LAA −950 HU	2.5 (1.3 - 4.3)
Emphysema; >5%LAA −950 HU,%	19.7
Lung volume on CT, liter	6.5 ± 1.4
Chronic Mucus Hypersecretion,%	29.7
Cough,%	32.7
Dyspnea,%	28.4
Wheezing,%	25.3
No respiratory symptoms,%	48.6

Mean ± standard deviation shown for continuous data and median(interquartile range) for non-parametric distribution.
Definition of abbreviations: HU = Hounsfield Units; Perc15= the threshold density value where 15% of all voxels has a lowerdensity; %LAA −950 HU = percentage low attenuation areas <−950 HU; >5%LAA −950 HU,% = percentage of thepopulation having >5% low attenuation areas < −950HU.

ISSN: 1465-993X