Table 1.
Baseline characteristics at the initial visit
| Total | Emphysema (−) | Emphysema (+) | P-value | |
|---|---|---|---|---|
| N | 628 | 543 | 85 | |
| Age (years), median (Q1, Q3) | 48 (40, 56) | 48 (40, 56) | 49 (42.5, 56) | 0.16 |
| Male sex | 474 (75.5%) | 403 (74.2%) | 71 (83.5%) | 0.08 |
| Height (cm) | 166.8±8.5 | 166.7±8.7 | 168.0±7.1 | 0.12 |
| Body weight (kg) | 67.1±10.9 | 66.8±10.9 | 69.0±10.3 | 0.10 |
| BMI | 24.0±3.0 | 24.0±2.9 | 24.4±3.3 | 0.21 |
| Current smoker | 271 (43.2%) | 241 (44.4%) | 30 (35.3%) | 0.13 |
| Noncurrent smoker | ||||
| Ex-smoker | 150 (23.9%) | 121 (22.3%) | 29 (34.1%) | 0.71 |
| Never smoker | 207 (33.0%) | 181 (33.3%) | 26 (30.6%) | |
| Pack years, median (Q1,Q3) | 10.0 (0, 22.5) | 10.0 (0, 22.5) | 8.5 (0, 20) | 0.87 |
| FU duration (years) | 3.1±1.4 | 3.1±1.4 | 3.2±1.4 | 0.87 |
| PFT | ||||
| FVC (L) | 4.02±0.84 | 4.00±0.84 | 4.18±0.82 | 0.06 |
| FVC (% predicted) | 98.0±11.0 | 97.7±10.8 | 99.9±12.1 | 0.08 |
| FEV1 (L) | 3.26±0.69 | 3.24±0.68 | 3.38±0.70 | 0.09 |
| FEV1 (% predicted) | 105.7±12.4 | 105.3±12.5 | 107.9±12.2 | 0.08 |
| FEV1/FVC (%) | 81.2±5.5 | 81.3±5.5 | 80.7±5.5 | 0.37 |
| %LAA−950, median (Q1, Q3) | 1.8 (0.6, 7.0) | 1.3 (0.5, 4.3) | 13.3 (11.2, 17.3) | <0.001 |
Note: %LAA−950 is the percentage of low-attenuation area below −950 Hounsfield units measured by computed tomography quantification.
Abbreviations: N, Number; Q1, first quartile; Q3, third quartile; BMI, body mass index; FU, follow-up; PFT, pulmonary function test; FVC, forced vital capacity; FEV1, forced expiratory volume in 1 second.