TABLE 2.
Clinical, anthropometric and polygraphic data for the three groups of subjects stratified according to obstructive sleep apnoea severity
| AHI <15 events·h−1 | AHI ≥15 events·h−1 and <30 events·h−1 | AHI ≥30 events·h−1 | p-value | |
| Subjects n | 354 | 277 | 170 | |
| BMI kg·cm−2 | 24.7±3.5 | 25.8±3.9 | 26.9±3.6 | <0.001 |
| Neck circumference cm | 35.7±3.6 | 37.3±3.9 | 39.5±3.7 | <0.001 |
| Hypertension % | 38 | 51 | 54 | 0.001 |
| Diabetes % | 1 | 2 | 4 | ns |
| Dyslipidaemia % | 37 | 35 | 30 | ns |
| Alcohol % | 40 | 49 | 53 | 0.009 |
| Smoking % | 23 | 27 | 28 | ns |
| SBP 24-h mmHg | 116.1±13.7 | 121.0±14.1 | 122.2±14.6 | <0.001 |
| DBP 24-h mmHg | 74.5±7.1 | 76.1±8.2 | 78.0±8.6 | <0.001 |
| SBP diurnal mmHg | 120.8±14.8 | 124.5±14.4 | 125.8±14.9 | <0.001 |
| DBP diurnal mmHg | 76.0±7.7 | 77.6±8.6 | 78.3±8.4 | 0.001 |
| SBP nocturnal mmHg | 103.9±14.9 | 108.7±16.4 | 105.3±14.1 | <0.001 |
| DBP nocturnal mmHg | 64.6±8.5 | 67.1±10.0 | 68.8±8.6 | <0.001 |
| BRS ms·mmHg−1 | 7.0±3.3 | 6.7± 3.4 | 7.0±4.1 | ns |
| AHI events·h−1 | 8.4±3.9 | 21.9±4.5 | 43.1±12.0 | 0.001 |
| ODI events·h−1 | 3.7±3.4 | 9.3±5.8 | 20.9±11.8 | <0.001 |
| Mean SpO2 % | 95.5±1.8 | 95.2±1.6 | 95.1±1.5 | 0.003 |
| Minimal SpO2 % | 91.1±2.9 | 89.0±4.2 | 87.6±4.6 | <0.001 |
| Time with SpO2 <90% % | 1.2±5.8 | 1.9±4.6 | 3.3±6.6 | <0.001 |
| Respiratory AAI events·h−1 | 8.9±5.2 | 15.9±6.5 | 28.9±11.3 | <0.001 |
Data are presented as mean±sd, unless otherwise stated. BMI: body mass index; SBP: systolic blood pressure; DBP: diastolic blood pressure; BRS: baroreceptor sensitivity; AHI: apnoea–hypopnoea index; ODI: oxygen desaturation index; SpO2: oxygen saturation measured by pulse oximetry; AAI: autonomic arousal index; ns: non-significant. Significance was determined by ANOVA.