Baseline characteristics in patients with idiopathic pulmonary fibrosis with or without concomitant pulmonary emphysema
| Characteristic | IPF with emphysema (n=29) | IPF alone (n=33) | P value |
| Age, years | 74±6 | 76±8 | 0.20 |
| Male, n (%) | 28 (97%) | 20 (60%) | |
| Body mass index | 21.9±3.2 (n=25) | 22.7±4.3 (n=29) | 0.40 |
| Smoking status | |||
| Smokers, n (%) | 29 (100%) | 14 (42%) | <0.001 |
| Pack-years | 59±68 | 12±20 | <0.001 |
| Comorbidity | |||
| Lung cancer, n (%) | 2 (7%) | 1 (3%) | 0.59 |
| Any cancer, n (%) | 5 (17%) | 3 (9%) | 0.33 |
| Diabetes mellitus, n (%) | 6 (21%) | 10 (30%) | 0.38 |
| Chronic heart failure, n (%) | 6 (21%) | 13 (39%) | 0.11 |
| Chronic renal failure, n (%) | 0 (0%) | 2 (6%) | 0.59 |
| Chronic respiratory infection, n (%) | 1 (3%) | 1 (3%) | 0.93 |
| Laboratory data | |||
| KL-6 in serum (U/mL) | 1266±697 (n=24) | 1255±817 (n=26) | 0.74 |
| Albumin in serum (g/mL) | 3.7±0.5 (n=20) | 3.7±0.3 (n=23) | 0.64 |
| Pulmonary functions | n=20 | n=17 | |
| FVC (L) | 2.26±0.68 | 1.54±0.61 | 0.045 |
| FVC, %predicted | 69.4±20.3 | 56.8±22.4 | 0.002 |
| FEV1 (L) | 1.9±0.5 | 1.3±0.4 | 0.001 |
| FEV1/FVC (%) | 85.9±7.6 | 89.3±9.2 | 0.11 |
| Thoracic CT | |||
| CT pattern (2018 IPF guideline) | |||
| Definite/probable/ indeterminate/alternative | 21/7/0/1 | 14/19/0/0 | 0.08 |
| Low-attenuation area score | 5.8±2.0 | 0.0±0.0 | < 0.001 |
| Treatment, n (%) | |||
| Prednisolone | 7 (24%) | 8 (24%) | 0.99 |
| Antifibrotic agents | 6 (20%) | 3 (9%) | 0.13 |
FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; IPF, interstitial pulmonary fibrosis; KL-6, Krebs von Lungen-6.