Table 2 Nonadjusted and adjusted associations between 6MWD and SSc characteristics
From: Factors associated with the 6-minute walk distance in patients with systemic sclerosis
| Â | Nonadjusted | Adjusted* | ||||
|---|---|---|---|---|---|---|
|  | β | (95% CI) | p | β | (95% CI) | p |
Male (vs female) | 52.7 | (21.8; 83.6) | <10–3 | 76.9 | (46.4; 107.4) | <10–3 |
Age (per 1-year increment) | –3.6 | (–4.5; –2.8) | <10–6 | –3.9 | (–4.8; –3.1) | <10–6 |
Smoking history (vs no history) | 31.8 | (6.9; 56.7) | 0.01 | –11.2 | (–34.9; 12.6) | 0.36 |
BMI (per 1-kg/m2 increment) | –4.1 | (–6.4; –1.7) | <10–3 | –3.7 | (–5.7; –1.6) | <10–3 |
dcSSc (vs lcSSc) | –0.7 | (–32.8; 31.5) | 0.97 | –40.2 | (–69.7; –10.8) | 0.008 |
Disease duration since diagnosis (per 1-year increment) | –1.8 | (–3.3; –0.3) | 0.02 | 0.7 | (–0.8; 2.2) | 0.38 |
Disease duration since first non-RP symptom (per 1-year increment) | –2.3 | (–3.8; –0.7) | 0.004 | –0.7 | (–2.3; 0.8) | 0.33 |
Disease duration since RP onset (per 1-year increment) | –1.2 | (–2.2; –0.2) | 0.02 | 0.4 | (–0.5; 1.4) | 0.38 |
ACA (vs no ACA) | –23.4 | (–48.1; 1.3) | 0.06 | –9.8 | (–35.5; 16.0) | 0.46 |
ATA (vs no ATA) | 0.1 | (–31.0; 31.3) | 0.99 | –2.4 | (–31.5; 26.8) | 0.87 |
ARA (vs no ARA) | 47.2 | (–33.2; 127.7) | 0.25 | 14.7 | (–61.6; 90.9) | 0.71 |
Anti-RNP antibodies (vs no anti-RNP antibodies) | 3.7 | (–52.2; 59.5) | 0.90 | –22.3 | (–71.0; 26.4) | 0.37 |
Abnormal nailfold capillaroscopy (vs normal) | –18.1 | (–86.7; 50.6) | 0.61 | –12.5 | (–66.9; 41.8) | 0.65 |
PAH (vs no PAH) | –131.8 | (–183.2; –80.3) | <10–6 | –112.0 | (–155.9; –68.2) | <10–3 |
ILD (vs no ILD) | Â | Â | 0.02 | Â | Â | 0.08 |
 Limited ILD | 16.4 | (–13.0; 45.3) |  | 14.2 | (–13.8; 42.2) |  |
 Extensive ILD | –52.3 | (–95.6; –9.0) |  | –40.4 | (–78.7; –2.1) |  |
DU (previously or at inclusion) (vs no DU) | 13.2 | (–11.6; 38.0) | 0.30 | –10.6 | (–33.7; 12.6) | 0.37 |
History of venous thrombosis (vs no history) | –65.0 | (–103.4; –26.5) | 0.001 | –52.5 | (–87.3; –17.6) | 0.003 |
History of arterial thrombosis (vs no history) | –73.6 | (–109.0; –38.1) | <10–3 | –43.5 | (–76.4; –10.6) | 0.01 |
History of cardiovascular disease (vs no history) | –103.8 | (–150.2; –57.5) | <10–3 | –65.0 | (–108.2; –21.8) | 0.003 |
Modified Rodnan skin score (per 1-point increment) | –0.4 | (–2.4; 1.7) | 0.74 | –0.9 | (–3.1; 1.3) | 0.42 |
Telangiectasia (vs no telangiectasia) | –12.4 | (–41.0; 16.1) | 0.39 | 13.4 | (–12.6; 39.4) | 0.31 |
NYHA functional class (vs class I) |  |  | <10–6 |  |  | <10–6 |
 NYHA class II | –76.1 | (–100.1; –52.2) |  | –61.7 | (–83.8; –39.6) |  |
 NYHA class III | –132.1 | (–160.8; –103.3) |  | –108.1 | (–134.5; –81.7) |  |
 NYHA class IV | –227.4 | (–303.1; –151.7) |  | –216.0 | (–281.6; –150.4 |  |
Cardiovascular symptoms (vs no symptoms) | –49.8 | (–94.6; –4.9) | 0.03 | –33.5 | (–73.3; 6.2) | 0.10 |
Joint symptoms (vs no symptoms) | –29.4 | (–54.3; –4.6) | 0.02 | –5.8 | (–28.4; 16.8) | 0.61 |
Muscle symptoms (vs no symptoms) | –27.8 | (–58.9; 3.4) | 0.08 | –16.1 | (–44.0; 11.8) | 0.26 |
Initial SpO2 (per 1% increment) | 14.9 | (9.2; 20.7) | <10–6 | 11.4 | (6.3; 16.4) | <10–3 |
Final SpO2 (per 1% increment) | 9.1 | (5.5; 12.8) | <10–3 | 7.2 | (3.9; 10.4) | <10–3 |
ΔSpO2 (per 1% increment) | 4.7 | (0.0; 9.4) | 0.05 | 3.7 | (–0.3; 7.8) | 0.07 |
Initial Borg score (per 1-point increment) | –22.5 | (–33.3; –11.7) | <10–3 | –21.5 | (–30.7; –12.3) | <10–3 |
Final Borg score (per 1-point increment) | –17.7 | (–23.0; –12.4) | <10–6 | –13.8 | (–18.6; –8.9) | <10–6 |
ΔBorg score (per 1-point increment) | –15.9 | (–22.1; –9.6) | <10–3 | –10.4 | (–16.3; –4.6) | <10–3 |
Initial sBP (per 1-mmHg increment) | –1.0 | (–1.7; –0.2) | 0.01 | 0.4 | (–0.3; 1.2) | 0.26 |
Final sBP (per 1-mmHg increment) | –0.6 | (–1.2; 0.1) | 0.11 | 0.8 | (0.1; 1.5) | 0.02 |
ΔsBP (per 1-mmHg increment) | 0.4 | (–0.5; 1.3) | 0.37 | 0.5 | (–0.2; 1.3) | 0.18 |
Initial dBP (per 1-mmHg increment) | 9.1 | (5.3; 12.8) | <10–3 | 7.1 | (3.9; 10.3) | <10–3 |
Final dBP (per 1-mmHg increment) | 0.5 | (–0.7; 1.8) | 0.42 | 0.1 | (–1.0; 1.2) | 0.91 |
ΔdBP (per 1-mmHg increment) | 0.6 | (–0.7; 1.8) | 0.36 | 0.0 | (–1.0; 1.1) | 0.95 |
Initial HR (per 1-bpm increment) | –1.9 | (–2.9; –0.9) | <10–3 | –2.0 | (–2.9; –1.2) | <10–3 |
Final HR (per 1-bpm increment) | –0.1 | (–0.9; 0.7) | 0.86 | 0.1 | (–0.6; 0.8) | 0.85 |
ΔHR (per 1-bpm increment) | 2.1 | (1.0; 3.2) | <10–3 | 2.5 | (1.6; 3.5) | <10–6 |
Hemoglobin (per 1-g/dl increment) | 26.6 | (18.0; 35.2) | <10–6 | 19.9 | (11.5; 28.2) | <10–3 |
ESR (per 1-mm/h increment) | –2.3 | (–3.1; –1.5) | <10–6 | –2.1 | (–2.8; –1.3) | <10–6 |
CRP (per 1-mg/L increment) | –5.8 | (–8.4; –3.3) | <10–3 | –5.8 | (–8.0; –3.5) | <10–3 |
Creatinin (per 1-mg/L increment) | –3.6 | (–8.0; 0.8) | 0.11 | –3.4 | (–7.3; 0.5) | 0.09 |
Estimated GFR (per 1-ml/min/1.73 m2 increment) | 1.1 | (0.6; 1.7) | <10–3 | 0.0 | (–0.6; 0.5) | 0.97 |
Elevated Nt-pro-BNP (vs normal Nt-pro-BNP) | –95.4 | (–128.7; –62.1) | <10–6 | –66.5 | (–98.4; –34.6) | <10–3 |
CK (per 1-IU increment) | 0.2 | (0.0; 0.4) | 0.11 | 0.2 | (0.0; 0.3) | 0.11 |
Ferritin (per 1-ng/ml increment) | 0.0 | (–0.1; 0.1) | 0.55 | 0.0 | (–0.1; 0.1) | 0.84 |
Complement activation (vs no activation) | 1.6 | (–70.0; 73.3) | 0.96 | 10.5 | (–51.2; 72.1) | 0.74 |
LVEF (per 1% increment) | 2.1 | (0.2; 4.1) | 0.03 | 2.1 | (0.4; 3.8) | 0.02 |
LVDD (vs no LVDD) | –69.6 | (–96.6; –42.7) | <10–6 | –17.1 | (–45.6; 11.4) | 0.24 |
Valvular heart disease (vs no valvular heart disease) | –22.5 | (–59.3; 14.2) | 0.23 | 26.2 | (–7.5; 59.9) | 0.13 |
Peak TRV (per 1-m/s increment) | –62.3 | (–101.0; –23.6) | 0.002 | –33.2 | (–67.4; 1.1) | 0.06 |
RA–RV pressure gradient (per 1-mmHg increment) | –2.5 | (–3.6; –1.5) | <10–3 | –1.8 | (–2.8; –0.9) | <10–3 |
Estimated sPAP (per 1-mmHg increment) | –2.5 | (–3.6; –1.4) | <10–3 | –1.9 | (–2.9; –0.9) | <10–3 |
RA area (per 1-cm2 increment) | –4.7 | (–8.2; –1.2) | 0.01 | –4.6 | (–8.4; –0.7) | 0.02 |
Abnormal IVC (vs normal IVC) | –26.0 | (–79.7; 27.6) | 0.34 | –22.5 | (–68.9; 24.0) | 0.34 |
Pericardial effusion (vs no pericardial effusion) | –57.4 | (–154.7; 39.9) | 0.25 | –95.3 | (–188.3; –2.2) | 0.05 |
TLC (per 1% increment) | 1.0 | (0.3; 1.8) | 0.007 | 1.1 | (0.4; 1.8) | 0.002 |
FVC (per 1% increment) | 0.4 | (–0.2; 0.9) | 0.20 | 1.2 | (0.7; 1.7) | <10–3 |
FEV1 (per 1% increment) | 0.3 | (–0.3; 0.9) | 0.29 | 1.0 | (0.5; 1.5) | <10–3 |
FEV1/FVC (per 1% increment) | 0.8 | (–0.3; 2.0) | 0.16 | –0.2 | (–1.3; 0.9) | 0.68 |
DLCO (per 1% increment) | 1.4 | (0.8; 2.0) | <10–3 | 1.5 | (1.0; 2.0) | <10–6 |
KCO (per 1% increment) | 0.7 | (0.0; 1.5) | 0.04 | 1.2 | (0.6; 1.9) | <10–3 |
EScSG-AI score (per 1-point increment) | –16.4 | (–26.2; –6.5) | 0.001 | –14.6 | (–23.5; –5.7) | 0.001 |
Medsger severity score (per 1-point increment) | –10.8 | (–16.3; –5.4) | <10–3 | –82.9 | (–99.8; –66.0) | <10–6 |
HAQ-DI score (per 1-point increment) | –104.6 | (–122.0; –87.2) | <10–6 | –11.1 | (–16.2; –6.1) | <10–3 |
Positive chronotropic drug intake (vs no intake) | –68.4 | (–136.5; –0.3) | 0.05 | –38.7 | (–98.6; 21.1) | 0.21 |
Negative chronotropic drug intake (vs no intake) | –48.1 | (–74.7; –21.4) | <10–3 | –15.3 | (–41.0; 10.5) | 0.25 |