Table 1. Baseline characterise and polysomnography parameters.
| Severity | |||||
| AHI ≦5 | 5< AHI ≦15 | 15< AHI ≦30 | AHI >30 | ||
| No. of subjects; (female/male) | 8 (0/8) | 11 (1/10) | 15 (1/14) | 20 (2/18) | |
| Age, yr | 43.4±3.5 | 42.2±3.2 | 40.1±2.5 | 45.6±2.7 | P = 0.505 |
| BMI, kg/m2 | 24.9±1.0 | 24.9±1.5 | 26.1±0.8 | 28.1±1.0 | P = 0.096 |
| NC, cm | 37.9±0.7 | 38.0±0.6 | 38.7±0.9 | 39.9±0.6 | P = 0.210 |
| Cholesterol, mg/dL | 203.1±13.1 | 210.7±21.2 | 188.2±10.5 | 189.3±16.2 | P = 0.568 |
| Smoker/Non | 3/5 | 4/7 | 6/9 | 9/11 | P = 0.968 |
| AHI, events/h | 1.9±0.6 | 10.2±0.8a | 20.1±1.1ab | 52.4±3.4abc | P<0.001 |
| ODI, events/h | 2.7±1.4 | 10.0±1.2a | 17.8±1.6ab | 51.4±4.6abc | P<0.001 |
| Sleep efficiency, % | 73.3±6.6 | 72.2±4.8 | 70.1±3.1 | 63.7±3.2 | P = 0.296 |
| Mean SaO2, % | 93.9±1.0 | 94.2±0.6 | 93.6±0.6 | 89.1±0.9abc | P<0.001 |
| Lowest SaO2, % | 88.6±2.2 | 84.8±1.2 | 79.1±1.6ab | 74.0±2.1ab | P<0.001 |
| Time with SaO2 <85%, minutes | 0.5±0.3 | 0.9±0.9 | 2.6±2.8a | 18.6±4.3abc | P<0.001 |
Definition of abbreviations: AHI = apnea-hypopnea index; BMI = body mass index; SaO2 = oxygen saturation; NC = neck circumference; ODI = 4% oxygen desaturation index. (mean ± SE, a: P<0.05 vs. AHI ≦ 5, b: P<0.05 vs. 5< AHI ≦ 15, c: P<0.05 vs. 15< AHI ≦30).