Table 3.
Baseline characteristics of patients with systemic sclerosis with vs. without clinically meaningful %-predicted diffusing capacity of carbon monoxide (DLCO) worsening
| Full Analytic Cohort (N=99) |
Radiographic ILD present (N=73) |
|||||
|---|---|---|---|---|---|---|
| Mean (SD) or N (%) | No significant decline in DLCO (N=88) |
Decline in % predicted DLCO ≥15 (N=11) |
p-value | No significant decline in DLCO (N=64) |
Decline in % predicted DLCO ≥15 (N=9) |
p-value |
| Age at time of HRCT, years | 49.9 (10.6) | 47.3 (12.6) | 0.530 | 49.0 (10.5) | 46.1 (13.7) | 0.564 |
| Sex, women | 72 (81.8) | 9 (81.8) | 1.000 | 52 (81.2) | 7 (77.8) | 1.000 |
| Race, white | 66 (75.0) | 9 (81.8) | 0.901 | 45 (70.3) | 7 (77.8) | 0.944 |
| Smoker, current or former | 30 (34.1) | 4 (36.4) | 1.000 | 22 (34.4) | 3 (33.3) | 1.000 |
| Gastrointestinal symptoms, present | 65 (73.9) | 8 (72.7) | 1.000 | 47 (73.4) | 7 (77.8) | 1.000 |
| Pulmonary symptoms, present | 56 (63.6) | 8 (72.7) | 0.795 | 44 (68.8) | 8 (88.9) | 0.392 |
| Proton pump inhibition, current | 49 (55.7) | 6 (54.5) | 1.000 | 38 (59.4) | 5 (55.6) | 1.000 |
| SSc disease subtype, diffuse | 38 (43.2) | 8 (72.7) | 0.126 | 31 (48.4) | 7 (77.8) | 0.196 |
| SSc disease duration, years* | 5.9 (8.4) | 3.4 (4.6) | 0.142 | 4.6 (5.8) | 3.9 (5.0) | 0.706 |
| Anti-Scl-70, positive | 32 (36.4) | 3 (27.3) | 0.795 | 30 (46.9) | 3 (33.3) | 0.684 |
| Anti-centromere, positive | 16 (18.2) | 0 (0.0) | 0.267 | 3 (4.7) | 0 (0.0) | 1.000 |
| Anti-RNA polymerase III, positive | 24 (27.3) | 4 (40.0) | 0.635 | 17 (26.6) | 3 (33.3) | 0.978 |
| Erythrocyte sedimentation rate | 24 (22.0) | 23 (20.2) | 0.908 | 23 (18.4) | 26 (19.9) | 0.718 |
| Modified Rodnan skin score | 11.0 (9.4) | 16.2 (8.6) | 0.083 | 11.8 (10.1) | 15.4 (9.2) | 0.294 |
| Medications, any use | 42 (47.7) | 7 (63.6) | 0.500 | 33 (51.6) | 6 (66.7) | 0.622 |
| Cyclophosphamide | 5 (5.7) | 0 (0.0) | 0.935 | 5 (7.8) | 0 (0.0) | 0.87 |
| Mycophenolate mofetil | 21 (23.9) | 2 (18.2) | 0.966 | 19 (29.7) | 2 (22.2) | 0.944 |
| Prednisone | 24 (27.3) | 3 (27.3) | 1.000 | 18 (28.1) | 2 (22.2) | 1.000 |
| Pulmonary hypertension present among those with RHC (N = 56) | 9 (25.0) | 4 (44.4) | 0.459 | 8 (30.8) | 4 (50.0) | 0.567 |
| Radiographic ILD, present | 64 (72.7) | 9 (81.8) | 0.777 | 64 (100.0) | 9 (100.0) | NA |
| FVC %-predicted, baseline | 78 (16.6) | 67 (14.1) | 0.034 | 76 (17.5) | 64 (13.6) | 0.038 |
| DLCO %-predicted, baseline | 58 (18.3) | 69 (19.3) | 0.103 | 56 (18.4) | 62 (12.9) | 0.184 |
| Digital ulcers, present | 33 (37.5) | 6 (54.5) | 0.445 | 26 (40.6) | 4 (44.4) | 1.000 |
| Widest esophageal diameter | 17.2 (8.6) | 19.5 (8.9) | 0.438 | 18.1 (8.1) | 20.0 (9.6) | 0.577 |
SSc disease duration defined as the interval between first non-Raynaud SSc symptom and baseline HRCT date. Widest esophageal diameter measured in mm; HRCT=high-resolution computed tomography of the chest; SSc=systemic sclerosis; ILD=interstitial lung disease; PAH=pulmonary arterial hypertension; RHC=right heart catheterization; FVC=forced vital capacity; DLCO=diffusing capacity of the lungs for carbon monoxide (adjusted for hemoglobin). Pulmonary and gastrointestinal symptoms defined as positive pulmonary and/or gastrointestinal review of systems in an outpatient rheumatology clinic note within one year of HRCT date.