Clinical, anthropometric and polygraphic data for the three groups of subjects stratified according to obstructive sleep apnoea severity

AHI <15 events·h−1AHI ≥15 events·h−1 and <30 events·h−1AHI ≥30 events·h−1p-value
Subjects n354277170
BMI kg·cm−224.7±3.525.8±3.926.9±3.6<0.001
Neck circumference cm35.7±3.637.3±3.939.5±3.7<0.001
Hypertension %3851540.001
Diabetes %124ns
Dyslipidaemia %373530ns
Alcohol %4049530.009
Smoking %232728ns
SBP 24-h mmHg116.1±13.7121.0±14.1122.2±14.6<0.001
DBP 24-h mmHg74.5±7.176.1±8.278.0±8.6<0.001
SBP diurnal mmHg120.8±14.8124.5±14.4125.8±14.9<0.001
DBP diurnal mmHg76.0±7.777.6±8.678.3±8.40.001
SBP nocturnal mmHg103.9±14.9108.7±16.4105.3±14.1<0.001
DBP nocturnal mmHg64.6±8.567.1±10.068.8±8.6<0.001
BRS ms·mmHg−17.0±3.36.7± 3.47.0±4.1ns
AHI events·h−18.4±3.921.9±4.543.1±12.00.001
ODI events·h−13.7±3.49.3±5.820.9±11.8<0.001
Mean SpO2 %95.5±1.895.2±1.695.1±1.50.003
Minimal SpO2 %91.1±2.989.0±4.287.6±4.6<0.001
Time with SpO2 <90% %1.2±5.81.9±4.63.3±6.6<0.001
Respiratory AAI events·h−18.9±5.215.9±6.528.9±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.