Annual changes in lung function and computed tomography parameters in current and former smokers (n = 53).

p* intra-group;p† inter-group. Data are expressed as medians (25th and 75th percentiles). Abbreviations: CT-TLV, total lung volume measured by computed tomography; Current, current smokers; D, index of low attenuation cluster analysis; FEV1, forced expiratory volume in one second; Former, former smokers; LAA%, ratio (%) of low attenuation area; LAN; number of low attenuation clusters.