Effect of High Altitude Exposure, Acclimatization and Re-exposure on Sustained Attention in Lowlanders

Study Overview
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Brief Summary
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Prospective interventional trial in lowlanders evaluating the effect of acute exposure, acclimatization and re-exposure to high altitude on global cognitive function.

Detailed Description
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Baseline measurements will be performed in Santiago de Chile, 520 m, over the course of 3 days. Participants will then travel by commercial airline (2 h flight) and by bus (2 h ride) to the ALMA base camp located at 2900 m near San Pedro de Atacama, northern Chile. Participants will stay there for the next 7 nights and they will be spend the days (6 total; 6-8 h daily) at the telescope station at 5050 m while undergoing testing as described above at the first and the last day at 5050m. Daily transports from 2900 to 5050 m will be by car (1 h ride, one way). After the first 7 day altitude sojourn participants will return to the Santiago area (520 m) for a 7 day recovery period. A second altitude sojourn with an identical schedule as the one described above and a final low altitude stay of 3 days will follow.

Official Title
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Effect of High Altitude Exposure, Acclimatization and Re-exposure on Global Cognitive Function

Conditions
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Effect of High Altitude

Intervention / Treatment
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* Other: Altitude exposure


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: born, raised and currently living <1300m No overnight stays at altitudes >1500m 4 weeks before the study Exclusion Criteria: previous altitude intolerance <3000m pregnancy health impairment, which requires regular treatment

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

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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Design Details

Primary Purpose: Prevention
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: altitude exposure<br>Altitude Exposure Acute high altitude exposure followed by 8 day acclimatization and reexposure for 8 days after 6 days at low altitude | Other: Altitude exposure<br>* Acute high altitude exposure followed by 8 day acclimatization and re-exposure for 8 days after 6 days at low altitude<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in global cognitive function assessed by neuropsychological test battery | Change in global cognition measured across two cycles of altitude exposure, comparing 5050m to 520m | Low altitude sojourn at 520m (Baseline); first sojourn at 5050m Day 2, 7; second sojourn at 5050m Day 2, 7 (each sojourn cycle = 7 days) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in cognitive subdomains (visual memory, executive function, working memory and planning, attention, semantic/verbal memory, decision-making and response control) assessed by neuropsychological test battery | Change in cognitive subdomains (visual memory, executive function, working memory and planning, attention, semantic/verbal memory, decision-making and response control) measured across two cycles of altitude exposure, comparing 5050m to 520m | Low altitude sojourn at 520m (Baseline); first sojourn at 5050m Day 2, 7; second sojourn at 5050m Day 2, 7 (each sojourn cycle = 7 days) | 
| Change in oxidative stress measured by venous blood sampling | Change in oxidative stress measured before and after high altitude exposure | Low altitude sojourn at 520m (Baseline); first sojourn at 5050m Day 2, 7; second sojourn at 5050m Day 2, 7 (each sojourn cycle = 7 days) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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High Altitude, Attention, Cognitive Function, Acclimatization, Sleep