Clinical characteristics and polysomnographic results
| Mild OSA (n = 17) | Moderate OSA (n = 18) | Severe OSA (n = 21) | |
| Age (years) | 49.8 (10.8) | 53.1 (10.4) | 56.8 (9.30) |
| Male gender (%) | 47.1 | 44.4 | 61.9*† |
| Body mass index (kg/m2) | 28.4 (7.3) | 29.2 (5.7) | 30.3 (6.2) |
| Neck circumference (cm) | 36.6 (4.1) | 37.2 (3.8) | 38.8 (3.9) |
| Hypertension (%) | 29.5 | 33.3 | 66.7*† |
| Systolic blood pressure (mm Hg) | 140.1 (20.3) | 134.5 (18.1) | 142.1 (19.5) |
| Diastolic blood pressure (mm Hg) | 88.8 (12.9) | 80.7 (11.8) | 86.8 (12.7) |
| Diabetes mellitus (%) | 0 | 0 | 19.9*† |
| Heart rate (beats/min) | 67.0 (13.4) | 60.4 (10.4) | 65.3 (9.4) |
| Sleep efficiency (%) | 86.6 (7.5) | 79.7 (13.4) | 83.5 (12.0) |
| Total sleep time (min) | 362.7 (95.6) | 353.8 (71.8) | 362.8 (83.2) |
| Stage 1 (%) | 7.8 (10.6) | 7.3 (7.3) | 6.7 (11.8) |
| Stage 2 (%) | 55.6 (13.6) | 46.0 (21.5) | 57.7 (18.6) |
| Slow wave sleep (%) | 18.3 (10.1) | 27.9 (14.0) | 24.8 (16.3) |
| Rapid eye movement sleep (%) | 19.0 (7.6) | 20.9 (13.7) | 15.4 (10.5) |
| Apnoea-hypopnoea index (events/h) | 9.9 (2.6) | 21.1 (3.7)* | 54.8 (22.5)*† |
| Microarousal index/h | 12.9 (6.50) | 16.6 (6.6)* | 25.2 (13.7)*† |
| O2 saturation nadir (%) | 87 (3.8) | 83.1 (10) | 76.1 (0.2)* |
*Different from mild, p<0.05; †different from moderate, p<0.05.