Effect of Acute Sleep Restriction on Responses to Hypoxia

Summary

At altitude, humans are exposed to environmental hypoxia induced by the decrease in barometric pressure. On duty or in training, mountain troops, paratroopers or aircrew are regularly exposed to altitude. The effects of altitude on humans occur gradually from 1500 m and depend on both the duration of exposure and the altitude level. Cognitive disorders can occur from 3500 m (threshold of disorders) but there is a very large inter-individual variability.

The countermeasure to altitude hypoxia is oxygen but its use is not systematic between 3000 and 4000 m. Its use depends on the duration of exposure, without clearly established standards. Incapacitating effects on the operational capacity and health of soldiers can therefore occur as early as 3500 m.

In operations or during training, altitude exposure is often associated with a significant sleep debt (particularly during night or early morning missions), jet lag or precarious rest conditions in overseas operations. These sleep restrictions promote the degradation of mental performance with effects similar to those observed in hypoxia.

The combination of these constraints induces a physiological stress which can favour alterations in mental performance, an increase in incapacity, intolerance to altitude or the occurrence of altitude-related pathologies in military personnel. This could occur in particular in the operational zone around the threshold of disorders (3500 m) where the indication of oxygen is discussed.

The objective of this study is to assess the impact of acute sleep restriction on hypoxia tolerance.

Conditions

• Sleep Deprivation
• Hypoxia

Interventions

OTHER

Hypoxia exposure

Each participant will be exposed to the hypoxic environment on 2 occasions (one after a normal sleep night and one after sleep deprivation). Each exposure will be for 5 hours at a FiO2 of 13.2% (3500 m simulated altitude). This exposure will be carried out in a normobaric hypoxic tent (Sporting Edge®).

OTHER

Sleep deprivation

Each participant will be exposed to sleep deprivation on 2 occasions (one before normoxia exposure and one before hypoxia exposure). Each sleep deprivation involves a time spent in bed of 3 hours (03h00 - 06h00). Sleep deprivation will be carried out in a sleep apartment. Sleep duration and quality will be assessed using a sleep headband (Dreem®), actigraphs Actiwatch® and E4 Empatica®) and a sleep diary.

BEHAVIORAL

Cognitive tasks

Participants will perform several cognitive tasks in the following conditions: * in normoxia (FiO2 = 21%) after a night of usual sleep (\> 6 hours) ; * in normoxia (FiO2 = 21%) after a night of reduced sleep (3 hours); * in normobaric hypoxia (FiO2 = 13.2%) after a night of normal sleep (\> 6 hours); * in normobaric hypoxia (FiO2 = 13.2%) after a night of reduced sleep (3 hours).

Sponsors & Collaborators

• Direction Centrale du Service de Santé des Armées

  lead OTHER

Eligibility

Min Age

18 Years

Max Age

45 Years

Sex

MALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2022-10-26

Primary Completion

2024-06-30

Completion

2024-06-30

Countries

• France

Study Locations