| Eucapnic OSA (n=50) | Hypercapnic OSA (n=38) | OSA+OHS (n=64) | Lone OHS (n=11) | |
| Male | 36 (72) | 22 (57.9) | 29 (45.3)* | 3 (27.3)* |
| Age (years) | 50.0±13.5 | 56.1±14.0* | 56.1±13.8* | 57.1±17.4 |
| Diabetes mellitus | 10 (20) | 17 (48.6)* | 32 (50.0)* | 4 (36.4) |
| Hypertension | 21 (42) | 24 (66.7) | 33 (51.6) | 5 (45.5) |
| BMl (kg/m2) | 44.0±11.4 | 46.11±10.0‡ | 53.72±13.9* † | 48.25±8.9 |
| ESS | 14.2±6.3 | 13.1±5.4‡ | 16.4±5.0* | 12.7±10.6* |
| FVC (L) | 3.0±1.1 | 1.9±1.0* | 1.9±0.9* | 1.5±0.6* |
| pH | 7.41±0.02 | 7.39±0.03* | 7.38±0.03* | 7.39±0.06 |
| PaO2 (kPa) | 10.4±1.6 | 8.0±1.5* | 8.0±1.5* | 7.8±1.3* |
| PaCO2 (kPa) | 5.4±0.4 | 7.0±0.7* ‡ | 7.6±1.3* † | 7.9±1.2* † |
| HCO3− (mmol/l) | 25.2±1.9 | 30.8±3.0* | 33.0±4.5* † | 33.5±5.2† |
| Length of stay (days) | 2.6±2.8 | 4.3±2.7* | 5.1±4.2* | 6.5±6.0* |
| 1-year mortality | 0 (0) | 1 (2.6) | 2 (3.1) | 1 (9.1) |
Data presented as n (%) or mean±SD.
OSA, obstructive sleep apnoea; OHS, obesity hypoventilation syndrome; BMI, body mass index; ESS, Epworth sleepiness score; FVC, forced vital capacity.
↵* Significant difference compared to eucapnic OSA group.
↵† Significant difference compared to hypercapnic OSA group.
↵‡ Significant difference between hypercapnic OSA group and combined group of OSA+OHS and lone OHS.