Comparison of polysomnography parameters for healthy children tested at low and high altitude

Vézina et al. [24]Ucros et al. [1]
Altitude MASL6452560
Patients n56232
Age years14–7
Average SpO2 %97.1 (10th centile 95.5)93 (5th centile 90.5)
SpO2 nadir %87.0 (10th centile 81.0)84 (5th centile 56.6)
ODI3 events·h−16.7 (90th centile 15.8)11.2 (95th centile 15.2)
Obstructive apnoea index events·h−10 (90th centile 0.5)
Obstructive AHI events·h−18.8 (95th centile 21.2)
Central apnoea index events·h−12.5 (90th centile 7.1)#
Central AHI events·h−10.4 (95th centile 2.4)
Hypopnoea index events·h−11.2 (90th centile 3.5)
Total AHI events·h−14.2 (90th centile 10.7)9.2 (95th centile 17.9)
  • Data are presented as medians with indicated centiles, unless otherwise stated. MASL: metres above sea level; SpO2: peripheral oxygen saturation; ODI3: 3% oxygen desaturation index; AHI: apnoea–hypopnoea index. #: this high central event rate in the lower altitude group is likely to be due to younger age.