Table 2.
Factors associated with ADU
| Characteristics | ADU− (n=120) | ADU+ (n=48) | P value | Adjusted OR (95% CI)* |
| Age, years±SD | 58.9±15.5 | 55.2±13.2 | 0.15 | ND |
| Female, n (%) | 107 (89.2) | 40 (83.3) | 0.31 | ND |
| Smoking, n (%) | 0.43 | ND | ||
| Current or past | 13 (11) | 7 (15) | ||
| Never | 100 (83) | 36 (75) | ||
| NA | 7 (6) | 5 (10) | ||
| SSc type, n (%) | 0.80 | ND | ||
| Limited | 50 (42) | 19 (40) | ||
| Diffuse | 70 (58) | 29 (60) | ||
| Disease duration, years±SD† | 7.3±12.7 | 10.4±15.1 | 0.19 | ND |
| Modified Rodnan skin score (0–51), mean (Q1, Q3) | 6.0 (2.0, 14.5) | 14.0 (8.0, 26.0) | < 0.001 | 1.06 (1.02 to 1.11 ) (p=0.007) |
| PAH | ||||
| Suspected PAH on echocardiography, n (%) | 13 (11) | 6 (13) | 0.76 | ND |
| sPAP (mm Hg), mean±SD | 31.9±14.7 | 31.5±10.9 | 0.90 | |
| PAH on RHC, n (%) | 8 (7) | 4 (8) | 0.70 | |
| mPAP (mm Hg), mean±SD | 31.8±9.6 | 29.6±21.8 | 0.73 | |
| LVEF on echocardiography (%), mean±SD | 65.4±9.8 | 67.6±6.7 | 0.23 | ND |
| ILD, n (%) | 47 (39) | 26 (54) | 0.08 | ND |
| FVC, % predicted ±SD | 97.3±17.4 | 88.3±26.9 | 0.09 | ND |
| DLCO, % predicted ±SD | 71±21.2 | 64.8±20.4 | 0.14 | ND |
| SSc-related autoantibodies, n (%) | ||||
| Anticentromere, n (%) | 60 (50) | 16 (33) | 0.05 | 0.64 (0.2 to 1.87) |
| Anti-Scl70, n (%) | 35 (29) | 25 (52) | 0.006 | 2.55 (0.91 to 7.14) |
| aPL, n (%) | ||||
| LA | 10 (8) | 7 (15) | 0.22 | ND |
| aCL (overall positivity) | 11 (9) | 3 (6) | 0.54 | ND |
| IgG | 8 (7) | 2 (4) | 0.57 | ND |
| IgM | 2 (2) | 1 (2) | 0.83 | ND |
| Anti-β2GP1 (overall positivity) | 5 (4) | 9 (19) | 0.002 | 8.71 (1.31 to 55.43 ) (p=0.02) |
| IgG | 1 (1) | 7 (16) | < 0.001 | ND |
| IgM | 4 (4) | 4 (9) | 0.17 | ND |
| APS, n (%) | 4 (3) | 3 (6) | 0.39 | ND |
| Overall arterial thrombosis history, n (%) | 3 (3) | 2 (4) | 0.61 | ND |
| Overall venous thrombosis history, n (%) | 12 (10) | 1 (2) | 0.08 | ND |
*Logistic regression with adjustment for anticentromere, anti-Scl70, modified Rodnan skin score, smoking, the presence of LA and/or aCL.
†Time from first non-Raynaud’s symptom.
aCL, anticardiolipin; ADU, active digital ulceration; aPL, antiphospholipid antibodies; APS, antiphospholipid syndrome; DLCO, diffusing capacity of the lung for carbon monoxide; FVC, forced vital capacity; β2GP1, beta-2 glycoprotein 1;Ig, immunoglobulin; IPD, interstitial pulmonary disease; LA, lupus anticoagulant; LVEF, left ventricular ejection fraction; mPAP, mean pulmonary arterial pressure; NA, not available ;ND, not done; PAH, pulmonary arterial hypertension; Q1/Q3, quartile 1/quartile 3; RHC, right heart catheterisation; sPAP, systolic pulmonary arterial pressure; SSc, systemic sclerosis.