Pulmonary function after mean 16.2 years of disease duration in patients with JMCTD and controls. Values are mean (SD) or median (range) unless otherwise specified.
| Variables | Patients with JMCTD, n = 52 | Controls, n = 52 | Mean Difference, % | p |
|---|---|---|---|---|
| FVC, l | 3.4 (0.6) | 4.3 (1.0) | < 0.001 | |
| FVC% | 89 (14.7) | 109 (11.9) | 20 | < 0.001 |
| FEV1, l | 2.9 (0.5) | 3.5 (0.8) | < 0.001 | |
| FEV1% | 89 (13.7) | 103 (11.0) | 14 | < 0.001 |
| FEV1/FVC ratio | 0.86 (0.06) | 0.82 (0.07) | 0.001 | |
| DLCO mmol/kPa | 6.8 (1.3) | 9.2 (2.4) | < 0.001 | |
| DLCO% | 73 (12.5) | 94 (16.0) | 21 | < 0.001 |
| DLCO/VA | 1.6 (0.2) | 1.8 (1.0) | 0.282 | |
| DLCO/VA% | 88 (12.7) | 92 (13.4) | 4 | 0.207 |
| TLC, l | 4.8 (1.0) | 6.0 (1.2) | < 0.001 | |
| TLC% | 90 (13.1) | 108 (10.6) | 18 | < 0.001 |
| Abnormal PFT* | 36 (69) | 13 (25) | < 0.001 | |
| FVC < 80%, n (%) | 11 (21) | 0 | < 0.001 | |
| FEV1 < 80%, n (%) | 12 (23) | 2 (4) | < 0.001 | |
| FEV1/FVC < 0.70, n (%) | 1 (2) | 3 (6) | 0.617 | |
| DLCO < 80%, n (%) | 35 (67) | 9 (17) | < 0.001 | |
| DLCO < 70%, n (%) | 19 (37) | 1 (2) | < 0.001 | |
| DLCO/VA < 80%, n (%) | 12 (23) | 8 (15) | 0.338 | |
| TLC < 80%, n (%) | 6 (12) | 0 | 0.009 | |
| 6MWT, m | 634.3 (76.5) | 698.9 (86.6) | 0.002 | |
| Borg CR10 scale | 2.0 (0–4.0) | 1.0 (0–3.0) | 0.072 |
↵* FVC, FEV1, and/or DLCO < 80% of expected value, and/or FVC/FEV1 < 70% of predicted. JMCTD: juvenile mixed connective tissue disease; FVC: forced vital capacity; FEV1: forced expiratory volume in 1 s; VC: vital capacity; VA: alveolar volume; TLC: total lung capacity; PFT: pulmonary function tests; 6MWT: 6-min walk test; CR: category ratio.