Sleep apneas and high altitude newcomers

Area of Science:

• High-altitude physiology
• Sleep medicine
• Respiratory control

Background:

• High altitude exposure significantly impacts sleep architecture and respiratory patterns.
• Periodic breathing (PB) is a common phenomenon at altitude, affecting both non-REM and REM sleep stages.
• The relationship between PB, sleep disturbances, and acute mountain sickness (AMS) requires further elucidation.

Purpose of the Study:

• To investigate sleep and respiration during high-altitude expeditions.
• To determine the factors influencing periodic breathing (PB) and its impact on sleep quality.
• To assess the effects of acclimatization and benzodiazepine administration on sleep and PB.

Main Methods:

• Collection of sleep and respiration data during two French high-altitude expeditions (Annapurna 4,800 m, Mt Sajama 6,542 m).
• Analysis of periodic breathing (PB) extent, arousals, wakefulness duration, and hypoxic ventilatory drive.
• Evaluation of sleep stages (including SWS), nocturnal desaturation, and AMS severity.
• Assessment of sleep patterns before and after acclimatization, and with loprazolam (1 mg) intake.

Main Results:

• Periodic breathing (PB) during non-REM and REM sleep was associated with sleep maintenance difficulties and decreased slow-wave sleep (SWS).
• PB extent correlated positively with hypoxic ventilatory drive and intercurrent wakefulness duration, not arousals.
• Acclimatization reduced PB latency and improved overall sleep quality.
• Loprazolam administration did not exacerbate SWS depression or apneas and facilitated sleep recovery post-acclimatization.

Conclusions:

• Periodic breathing (PB) significantly disrupts sleep at high altitudes, with its severity linked to individual hypoxic ventilatory drive.
• Acclimatization is crucial for mitigating PB and improving sleep quality during high-altitude exposure.
• Benzodiazepine use (loprazolam) appears safe concerning sleep disturbances and apneas in this context, aiding sleep recovery.