Distribution of polysomnography data
| Study group# | Control group# | ||||
| Variables | Mean±sd | Median (1st quartile–3rd quartile) | Mean±sd | Median (1st quartile–3rd quartile) | p-value |
| ESS scores | 7.4±5.56 | 6 (3.5–9.5) | 7.18±5.19 | 6 (3–10) | 0.837 |
| OSAS categories, n (%) | 0.786 | ||||
| Normal | 6 (10) | 4 (7) | |||
| Mild | 11 (18) | 14 (23) | |||
| Moderate | 23 (38) | 20 (33) | |||
| Severe | 20 (33) | 22 (37) | |||
| Total sleep time min | 349.17±60.58 | 352 (305.5–397) | 345.91±78.13 | 354 (280–409) | 0.021¶ |
| Stage N1% | 6.13±4.88 | 4.4 (2.8–8) | 7.62±3.59 | 7.7 (4.7–9.4) | 0.017 |
| Stage N2% | 61.42±11.4 | 59.1 (51.95–67.95) | 59.1±11.48 | 56.6 (49.4–67.5) | 0.947¶ |
| Stage N3% | 20.63±11.13 | 19.8 (13.3–26.9) | 18.27±9.53 | 18.65 (12.5–24.5) | 0.203 |
| REM sleep time min | 46.68±20.9 | 44 (35–60) | 54.4±33.42 | 45.25 (30–79) | 0.397 |
| REM % | 13.45±6.02 | 13.1 (10.2–16.3) | 15.43±8.07 | 15.75 (9.6–21.8) | 0.116 |
| Arousal index | 15.05±11.63 | 13.65 (7–20.5) | 10.58±9.99 | 9.3 (2.1–16.7) | 0.047 |
| AHI events·h−1 | 28.18±22.62 | 23.5 (12.9–34.35) | 28.27±20.82 | 22 (12.25–37.9) | 0.908 |
| RDI events·h−1 | 29.95±24.39 | 19.8 (11.3–47.8) | 40.22±23.14 | 41.3 (17.6–60.2) | 0.053 |
| REM-AHI | 30.81±26.85 | 27 (6.8–53.9) | 22.11±22.81 | 17.9 (0–40) | 0.041 |
| Supine-AHI | 14.03±20.11 | 5.6 (1.1–15.3) | 10.58±17.42 | 0.2 (0–20.3) | 0.016 |
| ODI events·h−1 | 26.39±29.23 | 18.65 (6.65–32.65) | 16.52±21.29 | 6.55 (1.25–22.25) | 0.002 |
| Mean Spo2 | 93.33±4.46 | 94 (93–95) | 93.31±2.67 | 94 (92–95) | 0.359 |
| Minimum Spo2 | 83±9.41 | 86 (83–89) | 83±9.05 | 86 (80–89) | 0.695 |
| T90% | 6.65±14.16 | 0.85 (0.2–3.6) | 9.19±15.28 | 1.9 (0.2–9.1) | 0.320 |
| T80% | 2.27±7.72 | 0 (0–0) | 1.65±7.57 | 0 (0–0) | 0.995 |
| Mean apnoea duration s | 17.58±7.32 | 15.4 (13.2–21.35) | 18.23±9.74 | 17.65 (12.8–23.9) | 0.615 |
| Mean hypopnoea duration s | 29.34±8.7 | 27.95 (22.25–34.75) | 29.1±6.92 | 28.2 (24.2–32.6) | 0.873 |
| MAD s | 26.93±7.0 | 26.7 (20.9–30.85) | 30.18±12.97 | 26.9 (24.2–32.8) | 0.347 |
Continuous data were expressed as mean±sd and median (1st–3rd quartile). ESS: Epworth Sleepiness Scale; OSAS: obstructive sleep apnoea syndrome; N1: non rapid-eye movement sleep stage 1; N2: non rapid-eye movement sleep stage 2; N3: deepest non rapid-eye movement sleep stage 3; REM: rapid eye movement; AHI: apnoea–hypopnoea index; RDI: respiratory disturbance index; ODI: oxygen desaturation index; Spo2: oxygen saturation measured by pulse oximetry; T90: oxygen saturation <90%; T80: oxygen saturation <80%; MAD: mean apnoea–hypopnoea duration. #: n=60; ¶: independent samples t-test was used, Mann-Whitney U test was used in other analyses. Bold font indicates p<0.05.