Effect of High Altitude Exposure, Acclimatization and Re-exposure on Cerebral Autoregulation in Lowlanders

Not Applicable

Completed

• Conditions: Effect of High Altitude
• Interventions: Other: altitude exposure

• Registration Number: NCT02829255
• Lead Sponsor: University of Zurich

Brief Summary

Prospective interventional trial in lowlanders evaluating the effect of acute exposure, acclimatization and re-exposure to high altitude on cerebral autoregulation

Detailed Description

Baseline measurements will be performed in Santiago de Chile, 520 m, over the course of 3 days. Participants will then travel by commercial airline (5 h flight) and by bus (3 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 8 nights and they will be spend the days (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 8 day altitude sojourn participants will return to the Santiago area (520 m) for a 6 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.

Study Timeline

• Study First Submitted: 2016-04-01
• Study Start: 2016-04-09
• Primary Completion: 2016-05-04
• Study Completion: 2016-05-04
• Study First Submitted QC: 2016-07-11
• Study First Posted: 2016-07-12
• Status Verified: 2019-01
• Last Update Submitted: 2019-01-15
• Last Update Posted: 2019-01-17

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 21

Inclusion Criteria

• Born, raised and currently living <800m
• No overnight stay at altitudes >1500 m 4 weeks before the study

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Exclusion Criteria

• Previous altitude intolerance to altitude <3000 m
• Pregnancy
• Health impairment, which requires regular treatment

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Altitude exposure	altitude exposure	Acute high altitude exposure followed by 8 day acclimatization and reexposure for 8 days after 6 days at low altitude

Primary Outcome Measures

Name	Time	Method
Coherence between middle cerebral artery blood flow velocity and systemic blood pressure as measure of cerebral autoregulation.	day 1; day 2 first cycle	Change in magnitude of the coefficient of coherence between blood flow velocity in the middle cerebral artery measured by transcranial ultrasound Doppler and systemic blood pressure at day 2 (5050 m) vs. day 1 (520 m) of the first cycle

Secondary Outcome Measures

Name	Time	Method
Coherence between middle cerebral artery blood flow velocity and systemic blood pressure as measure of cerebral autoregulation.	day 7 first cycle; day 7 second cycle	Change in magnitude of the coefficient of coherence between blood flow velocity in the middle cerebral artery measured by transcranial ultrasound Doppler and systemic blood pressure at day 7 (5050 m) second cycle vs. day 7 (5050 m) of the first cycle.

Trial Locations

Locations (1)

University of Zurich; 🇨🇭 Zurich, Switzerland