Baseline data of the interventional and control groups
| Variable | Combined (n=37) | Control (n=20) | Intervention (n=17) |
| Age (years) | 59.8±12.7 | 61.4±12.9 | 57.8±12.7 |
| Gender (M:F) | 11:26 | 7:13 | 4:13 |
| Weight (kg) | 140.3±29.4 | 141.2±30.7 | 139.3±28.8 |
| BMI (kg/m2) | 51.1±7.7 | 50.8±7.5 | 51.4±8.2 |
| Diabetes (%) | 49 (n=18) | 40 (n=8) | 59 (n=10) |
| Current smoker (%) | 16 (n=6) | 20 (n=4) | 12 (n=2) |
| FEV1 (L) | 1.49±0.61 | 1.54±0.65 | 1.43±0.58 |
| FVC (L) | 1.81±0.76 | 1.87±0.84 | 1.74±0.68 |
| PaO2 (kPa) | 8.53±1.76 | 8.48±1.85 | 8.58±1.71 |
| PaCO2 (kPa) | 7.16±0.93 | 7.10±0.82 | 7.21±1.05 |
| HCO3 - (mmol/L) | 31.9±3.61 | 31.6±3.22 | 32.3±4.1 |
| IPAP (cmH2O) | 26±5 | 26±5 | 27±4 |
| EPAP (cmH2O) | 11±3 | 11±3 | 11±2 |
| Back up rate (bpm) | 14±3 | 14±3 | 14±2 |
BMI, body mass index; EPAP, expiratory positive airway pressure; HCO3 -, arterial bicarbonate concentration; IPAP, inspiratory positive airway pressure.