Table 1.
Characteristics of cases and controls
| Characteristics | Cases | Controls |
|---|---|---|
| (n = 90) | (n = 90) | |
| Female, n (%) | 78 (87) | 78 (87) |
| Age (years), mean (SD) | 60 (15) | 59 (16) |
| Race, n (%) | ||
| Caucasian | 76 (84) | |
| Asian | 9 (10) | |
| Other | 5 (6) | |
| Duration of disease (years), mean (SD) | 14.3 (10.3) | |
| SSc subtype, n (%) | ||
| Diffuse disease | 23 (26) | |
| Limited disease | 62 (69) | |
| Sine | 1 (1) | |
| Mixed connective tissue disease | 4 (4) | |
| Autoantibodies, n (%) | ||
| Anti-topoisomerase I (Scl-70) | 17 (19) | |
| Anti-centromere | 38 (42) | |
| Anti-RNA polymerase III | 8 (9) | |
| Organ involvement, n (%) | ||
| Bowel dysmotility | 9 (10) | |
| Pulmonary arterial hypertension | 8 (9) | |
| Interstitial lung disease | 41 (46) | |
| Renal crisis | 4 (4) | |
| Gastroesophageal reflux disease | 83 (92) | |
| Disease activity/severity | ||
| Active digital ulcers, n (%) | 13 (14) | |
| mRSS, mean (SD) | 8.9 (7.3) | |
| SSc HAQ, mean (SD) | 20.5 (13.4) | |
| EUSTAR SSc activity score, mean (SD) | 2.2 (1.7) | |
| Immunosuppressive agents, n (%) | 28 (31) | |
| Past treatment with iloprost, n (%) | 17 (19) | |
| FVC (% predicted), mean (SD) | 91.5 (22.5) | |
| DLCO (% predicted), mean (SD) | 58.5 (18.8) | |
| 6MWD (meter), mean (SD) meters | 471.7 (126.1) |
6MWD, six-minute walk distance; DLCO, diffusing capacity of the lung for carbon monoxide; EUSTAR, EULAR Scleroderma Trials and Research Group; FVC, forced vital capacity; mRSS, modified Rodnan skin score; SD, standard deviation; SSc, systemic sclerosis; SSc HAQ, Scleroderma Health Assessment Questionnaire.