Effect of Acute Sleep Restriction on Responses to Hypoxia

Study Overview
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Brief Summary
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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.

Official Title
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Effect of Acute Sleep Restriction on Responses to Hypoxia

Conditions
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Sleep Deprivation, Hypoxia

Intervention / Treatment
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* Other: Hypoxia exposure
* Other: Sleep deprivation
* Behavioral: Cognitive tasks


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male Healthy Between 18 and 45 Smoking < 5 cigarettes per day or nicotine-free electronic cigarette Having regular physical activity (between 1 and 4 hours of physical activity per week) Affiliated or entitled to a social security plan No contraindication to physical exercise Having given their consent Exclusion Criteria: Female BMI > 30 Active medical pathology (cardiological, renal, hepatic, cutaneous, neurological, etc.), History of active pathology of less than 6 months Significant deviation with the normal values observed during the interrogation, clinical examination or electrocardiogram Having spent time at altitude (> 3500 m) during the last 3 months Absolute or relative contraindication to a stay at high altitude Medical contraindication to sport practice Skin allergy to modified ethanol or capsaicin Wearing a pacemaker or ferromagnetic implants Poor venous capital Pittsburgh Sleep Quality Index Questionnaire > 5 Usual sleep duration < 6 hours Not covered by a health insurance plan

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|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).|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean reaction time (in ms) to the 10-minute psychomotor vigilance task (PVT-10), at the end of the exposure. | PVT-10 is a sustained-attention, reaction-timed task that measures the consistency with which subjects respond to a visual stimulus. The participant sits in front of a computer. He has a screen in front of him with a 4-digit counter (0 at the start). He is instructed to click the left mouse button as fast as possible when the counter starts to scroll. The counter returns to zero when the participant has clicked. Reaction time (in ms) is calculated for each stimulus. | Through study completion (20.5 months) |