Demographic and pulmonary function characteristics
| Variable | Old n=21 | Old+ILA n=15 | P value |
| Age (years) | 67±6 | 70±9 | 0.2 |
| Gender, male (%) | 3 (14) | 12 (80) | 0.0001 |
| Smoke, former (%) | 8 (38) | 12 (80) | 0.01 |
| FVC (% predicted) | 104±33 | 99.8±13 | 0.7 |
| FEV1 (% predicted) | 103±20 | 105±20 | 0.7 |
| DLCO (% predicted) | 113±21 | 105±15 | 0.2 |
DLCO, diffusion capacity for carbon monoxide; FEV1, forced expiratory lung volume in the first second; FVC, forced vital capacity; ILA, interstitial lung abnormalities.