Table 1.
Demographics and clinical characteristics of the enrolled patients.
| Variables | All | PPF | Non-PPF | T/U/χ2 | p-value |
|---|---|---|---|---|---|
| N | 307 | 94 | 213 | ||
| Age, years | 58.6 ± 11.3 | 60.3 ± 11.8 | 57.8 ± 11.0 | 1.785 | 0.194 |
| Female, n (%) | 198 (64.5) | 54 (57.4) | 144 (67.6) | 2.939 | 0.086 |
| Smoking status, n (%) | 3.414 | 0.181 | |||
| Current | 35 (11.4) | 15 (16.0) | 20 (9.4) | ||
| Former | 44 (14.3) | 15 (16.0) | 29 (13.6) | ||
| Never | 228 (74.3) | 64 (68.1) | 164 (77.0) | ||
| BMI, Kg/m2, n (%) | 211 | 70 | 141 | 2.239 | 0.326 |
| <18.5 | 6 (2.8) | 3 (4.3) | 3 (2.1) | ||
| 18.5–24.9 | 110 (52.1) | 40 (57.1) | 70 (49.6) | ||
| ≥25.0 | 95 (45.0) | 27 (38.6) | 68 (48.2) | ||
| ILD onset, n (%) | 12.025 | 0.001 | |||
| Acute/subacute | 128 (41.7) | 53 (56.4) | 75 (35.2) | ||
| Chronic | 179 (58.3) | 41 (43.6) | 138 (64.8) | ||
| Cough, n (%) | 254 (82.7) | 80 (85.1) | 174 (81.7) | 0.533 | 0.465 |
| Dyspnea, n (%) | 251 (81.8) | 85 (90.4) | 166 (77.9) | 6.823 | 0.009 |
| PAH, n (%) | 18 (6.1) | 7 (7.7) | 11 (5.4) | 0.565 | 0.452 |
| PaO2 / FiO2, mmHg (IQR) | 280.7 (241.5–312.0) | 251.4 (220.3–293.4) | 291.4 (247.4–319.8) | 448.000 | 0.041 |
| CPI (SD) | 37.2 ± 16.7 | 43.2 ± 17.0 | 34.4 ± 15.9 | −3.816 | 0.835 |
| Pulmonary functions (SD) | |||||
| FVC, L | 2.39 ± 0.77 | 2.27 ± 0.81 | 2.44 ± 0.75 | 1.559 | 0.375 |
| FVC, % pred. | 80.44 ± 20.78 | 64.25 ± 16.73 | 82.00 ± 20.28 | 6.439 | 0.013 |
| DLCO SB, % pred. | 59.54 ± 18.66 | 41.42 ± 13.29 | 62.74 ± 18.41 | 8.740 | 0.022 |
| Fever, n (%) | 81 (26.4) | 29 (30.9) | 52 (24.4) | 1.392 | 0.238 |
| Proximal musculature weakness, n (%) | 29 (9.4) | 7 (7.4) | 22 (10.3) | 0.633 | 0.426 |
| Dysphagia, n (%) | 7 (2.3) | 0 (0.0) | 7 (3.3) | 3.161 | 0.075 |
| Skin rash, n (%) | 59 (19.2) | 17 (18.1) | 42 (19.7) | 0.112 | 0.738 |
| Gottron’s sign, n (%) | 23 (7.5) | 7 (7.4) | 16 (7.5) | 0.000 | 0.984 |
| Mechanic’s hands, n (%) | 38 (12.4) | 7 (7.5) | 31 (14.6) | 2.939 | 0.086 |
| Photosensitivity, n (%) | 22 (7.2) | 3 (3.2) | 19 (8.9) | 3.217 | 0.093 |
| Fingertip hardening, n (%) | 9 (2.9) | 3 (3.2) | 6 (2.8) | 0.032 | 1.000 |
| Joint pain, n (%) | 81 (26.4) | 22 (23.4) | 59 (27.7) | 0.619 | 0.431 |
| Joint swelling, n (%) | 18 (5.9) | 5 (5.3) | 13 (6.1) | 0.073 | 0.788 |
| Morning stiffness, n (%) | 23 (7.5) | 8 (8.5) | 15 (7.0) | 0.203 | 0.652 |
| Raynaud’s phenomenon, n (%) | 12 (3.9) | 5 (5.3) | 7 (3.3) | 0.717 | 0.397 |
| Vasculitis, n (%) | 3 (1.0) | 2 (2.1) | 1 (0.5) | 1.853 | 0.223 |
| Dry eye, n (%) | 56 (18.2) | 27 (28.7) | 29 (13.6) | 9.982 | 0.002 |
| Dry mouth, n (%) | 74 (24.1) | 34 (36.2) | 40 (18.8) | 10.782 | 0.001 |
| Rampant caries, n (%) | 15 (4.9) | 10 (10.6) | 5 (2.3) | 9.647 | 0.002 |
| Hair loss, n (%) | 14 (4.6) | 6 (6.4) | 8 (3.8) | 1.034 | 0.309 |
| Mouth ulcers, n (%) | 10 (3.3) | 5 (5.3) | 5 (2.3) | 1.828 | 0.176 |
| Gastroesophageal reflux, n (%) | 16 (5.2) | 4 (4.3) | 12 (5.6) | 0.251 | 0.783 |
Data was presented as mean ± SD or n (%). MSA, myositis-specific antibodies; IP, interstitial pneumonia; PPF, progressive pulmonary fibrosis; BMI, body mass index; ILD, interstitial lung disease; PAH, pulmonary hypertension; CPI, composite physiologic index; FVC, forced vital capacity; DLCO, diffusing capacity of the lung for carbon monoxide; SD, standard deviation.