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 (%) | Â | Â |
  Caucasian | 76 (84) |  |
  Asian | 9 (10) |  |
  Other | 5 (6) |  |
Duration of disease (years), mean (SD) | 14.3 (10.3) | Â |
SSc subtype, n (%) | Â | Â |
  Diffuse disease | 23 (26) |  |
  Limited disease | 62 (69) |  |
  Sine | 1 (1) |  |
  Mixed connective tissue disease | 4 (4) |  |
Autoantibodies, n (%) | Â | Â |
  Anti-topoisomerase I (Scl-70) | 17 (19) |  |
  Anti-centromere | 38 (42) |  |
  Anti-RNA polymerase III | 8 (9) |  |
Organ involvement, n (%) | Â | Â |
  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 | Â | Â |
  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) |  |