Characteristics of the obstructive sleep apnoea syndrome and control groups
| Variable | Patients | Controls | p-values |
| Subjects n | 20 | 20 | |
| Age yr | 54.1±5.9 | 52.2±8.3 | NS |
| BMI kg·m-2 | 28.9±4.9 | 24.3±2.7 | <0.01 |
| RDI | 44.4±13 | 4.5±3.9 | <0.001 |
| Mean nocturnal O2 sat % | 93.9±1.0 | 96.0±0.8 | <0.001 |
| Time spent with O2 sat <90% min | 2.9±4.5 | 0 | <0.001 |
| Epworth Sleepiness Scale | 11.4±3.4 | 8.4±2.7 | 0.02 |
Data are expressed as mean±sd, unless otherwise stated. BMI: body mass index; RDI: the number of apnoeas and hypopnoeas per hour of sleep recording; O2 sat: oxygen saturation; NS: non-significant (p>0.05).