Alveolar concentration of exhaled nitric oxide(CA,NO) and conducting airway flux of nitric oxide (J′aw,NO) from systemic sclerosis patients (SSc) and healthy volunteers
| SSc | Control | p-value | |
| Subjects n | 58 | 19 | |
| Age yrs | 53.5 (45–60) | 42.7 (28.1–50.4) | 0.01 |
| Smoker n | 10 | 0 | |
| Duration of disease yrs | 5.5 (3.0–10.4) | ||
| Modified Rodnan skin score | 8 (4–13) | ||
| J′aw,NO nL·min−1 | 6.3 (−9.8–31.3) | 35.5 (25.8–54.9) | <0, 001 |
| CA,NO ppb | 6.2 (3.8–9.9) | 2.0 (1.2–3.0) | <0.001 |
| R2 | 0.95 (0.92–0.98) | 0.96 (0.95–0.98) | ns |
| FeNO50 ppb | 10.1 (5.9–17.8) | 13.1 (11.6–19.6) | ns |
| TLC % pred | 92 (77–105) | ||
| FVC % pred | 90 (75–104) | ||
| FEV1 % pred | 88 (74–101) | ||
| Pa,O2 mmHg | 85 (80–98) | ||
| DL,CO % pred | 61 (46–71) | ||
| DL,CO/AV % pred | 74 (64–85) | ||
| sPAP mmHg | 31 (26–36) | ||
| sPAP ≥40 mmHg | 8 |
Data are presented as median (1st–3rd quartile), unless otherwise stated. R2: relationship between the elimination rate of nitric oxide (NO) and exhalation flow rate; FeNO50: fractional exhaled NO concentrationat 50 mL·s−1 constant flow rate; TLC: total lung capacity; % pred: % predicted; FVC: forced vital capacity; FEV1: forced expiratory volume in one second; Pa,O2: arterial oxygen tension; DL,CO: diffusing capacity of the lung for carbon monoxide; AV: alveolar volume; sPAP: systolic pulmonary artery pressure; ns: nonsignificant. 1 mmHg = 0.133 kPa.