Characteristics | Total, n = 56 | Patients with SSc | p | |
---|---|---|---|---|
Abnormal 6MWT, n = 25 | Normal 6MWT, n = 31 | |||
Age, yrs | 45.6 ± 12.7 | 41.0 ± 11.6 | 49.3 ± 12.1 | 0.01 |
Sex | ||||
Female | 38 (67.9) | 17 (68.0) | 21 (67.7) | 0.98 |
Male | 18 (32.1) | 8 (32.0) | 10 (32.3) | |
BMI, kg/m2 | 23.1 ± 4.2 | 22.1 ± 4.6 | 23.9 ± 3.6 | 0.11 |
Disease duration, mos | 33.6 ± 44.0 | 36.5 ± 32.2 | 31.4 ± 51.8 | 0.67 |
Diffuse subtype | 39 (70) | 19 (76) | 20 (65) | 0.35 |
Performance status | ||||
0 | 11 (20) | 2 (8) | 9 (29) | 0.09 |
1 | 35 (63) | 15 (60) | 20 (65) | 0.79 |
2 | 10 (18) | 8 (32) | 2 (7) | 0.01 |
SHAQ | 1.02 ± 0.8 | 1.34 ± 0.7 | 0.76 ± 0.7 | 0.005 |
mRSS | 17 ± 10 | 19 ± 11 | 16 ± 10 | 0.21 |
Tendon friction rub | 5 (9) | 5 (20) | 0 | 0.02 |
Arthralgia | 19 (46) | 14 (74) | 5 (23) | 0.001 |
Calcinosis | 5 (9) | 3 (12) | 2 (7) | 0.64 |
Myalgia | 11 (26) | 7 (33) | 4 (18) | 0.31 |
Muscle disease score | 7.8 ± 9 | 10.7 ± 12 | 5.4 ± 6 | 0.001 |
Blood pressure at rest | ||||
Systolic, mmHg | 116 ± 19 | 116 ± 16 | 120 ± 20 | 0.10 |
Diastolic, mmHg | 79 ± 86 | 66 ± 10 | 89 ± 114 | 0.32 |
Heart rate at rest, bpm | 78 ± 13 | 79 ± 13 | 77 ± 13 | 0.63 |
Respiratory rate at rest, breaths/min | 17 ± 3 | 17 ± 4 | 16 ± 3 | 0.88 |
Presence of rales | 17 (30) | 6 (24) | 11 (36) | 0.35 |
NYHA at rest | ||||
1 | 19 (53) | 8 (44) | 11 (61) | 0.38 |
2 | 14 (39) | 9 (50.0) | 5 (28) | |
3 | 3 (8) | 1 (6) | 2 (11) | |
6MWD | ||||
Total 6MWD | ||||
Absolute value, m | 457 ± 117 | 373 ± 106 | 524 ± 73 | 0.0001 |
Relative value, % | 75 ± 20 | 58 ± 15 | 88 ± 10 | 0.04 |
Borg score | 4.0 ± 2 | 3.7 ± 2 | 4.3 ± 2 | 0.38 |
Pulmonary function tests | ||||
FVC, % | 84 ± 26 | 77 ± 24 | 91 ± 26 | 0.05 |
DLCO, % | 58 ± 17 | 53 ± 17.3 | 62 ± 16 | 0.05 |
Abnormal chest radiograph or HRCT | 31 (67) | 16 (76) | 15 (60) | 0.24 |
Transthoracic echocardiography variables | ||||
LVEF, % | 69 ± 9 | 65 ± 8 | 72 ± 8 | 0.003 |
TRV, m/s | 1.9 ± 1.3 | 2.2 ± 1.3 | 1.6 ± 1.3 | 0.22 |
PASP, mmHg | 32 ± 9 | 33 ± 8 | 31 ± 10 | 0.47 |
PAH | 3 (5) | 1 (4) | 2 (7) | 0.69 |
Laboratory tests | ||||
Hemoglobin level, g/dl | 12.4 ± 1.4 | 12.1 ± 1.6 | 12.7 ± 1.1 | 0.10 |
Serum creatinine, μmol/l | 70 ± 46 | 62 ± 12 | 76 ± 62 | 0.28 |
C-reactive protein, mg/l | 15 ± 19 | 14 ± 18 | 16 ± 20 | 0.78 |
Serum CPK, IU/l | 218 ± 324 | 269 ± 381 | 169 ± 257 | 0.29 |
Immunological profile | ||||
ANA | 56 (100) | 25 (100) | 31 (100) | – |
Anticentromere antibodies | 5 (9) | 2 (8) | 3 (10) | 0.79 |
Antitopoisomerase I antibodies | 33 (59) | 15 (60) | 18 (58) | 0.88 |
aPL | 6 (15) | 3 (18) | 3 (14) | 0.73 |
Treatment at baseline | ||||
Oxygen | 1 (2) | 1 (4) | 0 | – |
Corticosteroids | 27 (48) | 14 (56) | 13 (42) | 0.30 |
Cyclophosphamide | 10 (18) | 6 (24) | 4 (13) | 0.32 |
Mycofenolate mofetil | 4 (7) | 3 (12) | 1 (3) | 0.31 |
Methotrexate | 2 (4) | 1 (4) | 1 (3) | 0.88 |
Bosentan | 1 (2) | 0 | 1 (3) | – |
SSc: systemic sclerosis; 6MWT: 6-minute walk test; BMI: body mass index; SHAQ: Scleroderma Health Assessment Questionnaire; mRSS: modified Rodnan skin score; NYHA: New York Heart Association; 6MWD: 6-minute walk distance; FVC: forced vital capacity; HRCT: high-resolution computed tomography of the chest; LVEF: left ventricular ejection fraction as measured by cardiac echography; TRV: tricuspid regurgitation peak velocity; PASP: pulmonary arterial systolic hypertension; PAH: pulmonary arterial hypertension; ANA: antinuclear antibodies; aPL: antiphospholipid antibodies; CPK: creatine phosphokinase.