Figures & data
Figure 1. CONSORT diagram for the Thoracic Imaging Network of Canada (TINCan) cohort study. Of the 266 enrolled, 172 ex-smokers with and without COPD completed the baseline visit (Visit 1), while 90 ex-smokers completed the follow-up visit (Visit 2) and were included in the analysis.
Table 1. Participant demographics at baseline and three-year follow-up for ex-smokers with and without COPD.
Table 2. Participant demographics at baseline and three-year follow-up for ex-smokers with COPD according to GOLD grade.
Figure 2. Arrows showing progression in severity at follow-up for all participants (n = 90), including ex-smokers without COPD (n = 40) and ex-smokers with COPD (n = 50) within GOLD grade severity subgroups. Of the 40 ex-smoker participants at baseline, two transitioned to GOLD I at follow-up and one transitioned to GOLD II. Of the 24 GOLD II participants, five transitioned to GOLD III. Of the 10 GOLD III participants, two transitioned to GOLD IV.
Figure 3. Baseline and three-year follow-up CT imaging for representative ex-smokers with and without COPD. P37 is a 70-year-old female ex-smoker without COPD, with follow-up time = 31 months (baseline/follow-up: FEV1%pred = 93%/93%; RA950 = 1%/1%; TAC = 306/297). P10 is a 75-year-old male ex-smoker with GOLD I COPD, with follow-up time = 33 months (baseline/follow-up: FEV1%pred = 92%/84%; RA950 = 7%/8%; TAC = 265/231). P74 is an 83-year-old male ex-smoker with GOLD II COPD, with follow-up time = 28 months (baseline/follow-up: FEV1%pred = 57%/52%; RA950 = 20%/23%; TAC = 258/191). P78 is a 67-year-old female ex-smoker with GOLD III COPD, with follow-up time = 26 months (baseline/follow-up: FEV1%pred = 37%/33%; RA950 = 33%/37%; TAC = 206/174). Left: Coronal CT reconstruction with RA950 shown in yellow. Right: Three-dimensional reconstruction of the segmented airway tree.
Table 3. Pulmonary function, exercise capacity, quality-of-life, and imaging measurements at baseline and three-year follow-up for ex-smokers with and without COPD.
Table 4. Pulmonary function, exercise capacity, quality-of-life, and imaging measurements at baseline and three-year follow-up for ex-smokers with COPD according to GOLD grade.
Table 5. Pulmonary function, exercise capacity, quality-of-life, and imaging measurements at baseline and three-year follow-up for ex-smokers with and without COPD who did not progress in GOLD grade.
Figure 4. Schematic showing decreased TAC in ex-smokers with COPD. Schematic also shows decreased airway WA% and increased LA and VDP in ex-smokers without COPD (ES), as well as decreased airway WA, WA%, and WT%, and increased LA and VDP in ex-smokers with COPD.
Figure 5. Scatter plots showing Spearman (ρ) and Pearson (r) correlations in all ex-smokers at baseline, three-year follow-up, and the longitudinal change between baseline and follow-up (Δ). TAC was correlated with FEV1 (baseline: ρ = 0.38, p < 0.001; follow-up ρ = 0.48, p < 0.001). ΔTAC was correlated with ΔFEV1 (r = 0.38, p < 0.001). TAC was correlated with VDP (baseline: ρ = –0.30, p = 0.005; follow-up: ρ = –0.33, p = 0.002). ΔTAC was correlated with ΔVDP (ρ = –0.37, p < 0.001).
Table 6. Multivariable linear regression models.
Table 7. Correlations for potential predictor variables in linear regression models.
Supplemental Material
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Data generated or analyzed during the study are available from the corresponding author upon request.