Table 1.
Clinical characteristics of study population at baseline
| Variables | Total | No-PH | Bo-PH | PH | p-value* |
|---|---|---|---|---|---|
| mPAP ≤20 | 20 < mPAP < 25 | mPAP ≥25 | |||
| Subjects, N (%) | 80 | 56 | 18 | 6 | – |
| Mean age (years) | 71.2 ± 10.3 | 70.7 ± 11.0 | 76.7 ± 6.46 | 73.4 ± 5.32 | 0.916 |
| BMI (kg/m2) | 22.5 ± 3.99 | 21.9 ± 3.38 | 21.4 ± 2.99 | 22.7 ± 4.11 | 0.182 |
| Smoking status, current/former/never | 6/40/34 | 5/25/26 | 1/10/7 | 0/5/1 | 0.352 |
| Underlying disease | |||||
| IPF, N (%) | 23 (28.8) | 17 (30.3) | 2 (11.1) | 4 (66.7) | 0.030 |
| CPFE, N (%) | 8 (10.0) | 5 (8.9) | 2(11.1) | 1 (16.7) | 0.822 |
| CTD-ILD, N (%) | 15 (18.8) | 11 (19.6) | 4 (22.2) | 0 (0) | 0.459 |
| Other ILD, N (%) | 34 (42.5) | 23 (41.1) | 10 (55.6) | 1 (16.7) | 0.230 |
| KL-6 (U/ml) | 1030(628, 1569) | 968 (660, 1448) | 965 (420, 1575) | 1280(909, 1526) | 0.521 |
| PaO2(mmHg) | 75.4 ± 9.2 | 76.7 ± 9.3 | 73.0 ± 9.0 | 73.1 ± 9.9 | 0.117 |
| VC, % predicted (%) | 74.6 ± 22.9 | 72.7 ± 22.5 | 67.9 ± 23.8 | 79.3 ± 19.0 | 0.436 |
| FEV1, % predicted (%) | 90.3 ± 25.3 | 87.8 ± 26.1 | 84.5 ± 18.1 | 93.5 ± 24.5 | 0.637 |
| TLC, % predicted (%) | 76.9 ± 17.7 | 76.0 ± 16.2 | 74.3 ± 21.2 | 78.6 ± 14.4 | 0.966 |
| DLco, % predicted (%) | 50.5 ± 22.6 | 52.5 ± 24.2 | 48.2 ± 24.3 | 41.3 ± 22.6 | 0.530 |
| 6MWD (m) | 342.0 ± 130.1 | 383.8 ± 101.6 | 235.2 ± 95.3 | 169.2 ± 140.0 | < 0.0001 |
| ΔSpO2(%) | 7.60 ± 4.06 | 7.31 ± 4.00 | 10.0 ± 4.14 | 9.80 ± 2.28 | 0.024 |
| RVSP (mmHg) | 30 (24, 35) | 28 (22.5, 33) | 33 (30, 38) | 48.5 (38.8, 52.3) | < 0.0001 |
| mPAP(mmHg) | 16.5 (14, 21) | 15 (13, 17) | 21 (21, 22) | 27.5 (25.5, 28.8) | < 0.0001 |
| PVR (dynes・sec・cm−5) | 195 (152, 287) | 180 (145, 210) | 281 (211, 317) | 378 (320, 494) | < 0.0001 |
| Cardiac index(l/min/m2) | 2.54 (2.27, 2.76) | 2.51 (2.21, 2.71) | 2.71 (2.54, 3.01) | 2.64 (2.17, 2.74) | 0.035 |
| PAWP (mmHg) | 6.23 ± 2.68 | 5.93 ± 2.62 | 7.46 ± 2.96 | 4.60 ± 1.82 | 0.056 |
Data are presented as mean ± standard deviation or median (interquartile range). *p-value is comparison among the three groups (No-PH, Bo-PH, and PH groups). Definition of abbreviations: PH, pulmonary hypertension; BMI, body mass index; IPF, idiopathic pulmonary fibrosis; CPFE, combined pulmonary fibrosis and emphysema; ILD, interstitial lung disease; CTD-ILD, connective tissue disease associated with ILD; KL-6, krebsvon den lungen-6; PaO2, partial pressure of oxygen; VC, vital capacity; FEV1, forced expiratory volume in 1 s;TLC, total lung capacity; DLco, diffusing capacity for carbon monoxide; 6MWD, 6-min walk distance; SpO2, oxygen saturation as measured by pulse oximeter;ΔSpO2, initial SpO2–lowest SpO2on 6-min walk test; RVSP, right ventricular systolic pressure; mPAP, mean pulmonary artery pressure; PVR, pulmonary vascular resistance; PAWP, pulmonary arterial wedge pressure