| CPAP(N = 18) | BVS(N = 18) | p Value | |
| Age (years) | 52 (17) | 47 (13) | 0.29 |
| Sex (M:F) | 14:4 | 9:9 | 0.09 |
| BMI (kg/m2) | 52 (7) | 54 (9) | 0.49 |
| Awake Spo2 (%) | 90 (86–92) | 87 (84–93) | 0.86 |
| Baseline Paco2 (mm Hg) | 52 (49–55) | 49 (47–57) | 0.36 |
| Bicarbonate (mmol/l) | 30 (29–33) | 30 (29–32) | 0.56 |
| FEV1/FVC ratio (%) | 81 (6) | 81 (7) | 0.72 |
| Neck circumference (cm) | 50 (4) | 51 (5) | 0.53 |
| Waist:hip ratio | 0.99 (0.09) | 0.97 (0.13) | 0.51 |
Data presented as mean (SD) or median (interquartile range) as appropriate.
BMI, body mass index; BVS, bilevel ventilatory support; CPAP, continuous positive airway pressure; Spo2, oxygen saturation; Paco2, arterial carbon dioxide tension; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity.