Effect of High Altitude Exposure, Acclimatization and Re-exposure on Nocturnal Breathing Pattern in Lowlanders

Not Applicable

Completed

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

• Registration Number: NCT02730143
• Lead Sponsor: University of Zurich

Brief Summary

Prospective interventional trial in lowlanders evaluating the effect of acute exposure, acclimatization and re-exposure of high altitude on nocturnal breathing pattern.

Detailed Description

Respiratory polygraphies 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 7 nights and respiratory polygraphies will be performed on night 1 and 6. They will be spend the days (6-8 h daily) at the telescope station at 5050 m while undergoing physiological testing. 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: 2016-03-31
• Study First Submitted QC: 2016-03-31
• Study Start: 2016-04-04
• Study First Posted: 2016-04-06
• Primary Completion: 2016-05-07
• Study Completion: 2016-05-07
• Status Verified: 2018-11
• Last Update Submitted: 2018-11-08
• Last Update Posted: 2018-11-13

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 re-exposure after 6 days at low altitude

Primary Outcome Measures

Name	Time	Method
Mean nocturnal oxygen saturation measured by pulse oximetry	first sojourn at 5050 m, night 1, 6; second sojourn at 5050 m, night 1, 6; low altitude sojourn at 520 m, night 1	Change in mean nocturnal oxygen saturation over the course of high altitude exposure during 2 sojourns at 5050 m compared to low altitude

Secondary Outcome Measures

Name	Time	Method
Acute mountain sickness measured by the Environmental Symptom questionnaire cerebral score (AMSc)	first sojourn at 5050 m, day 2, 7; second sojourn at 5050 m, day 2,7; low altitude sojourn at 520 m, day 2	Incidence of acute mountain sickness (AMSc score \>= 0.7) over the course of high altitude exposure during 2 sojourns at 5050 m compared to low altitude
Oxygen desaturation index measured by respiratory polygraphy	first sojourn at 5050 m, night 1, 6; second sojourn at 5050 m, night 1, 6; low altitude sojourn at 520 m, night 1	Change in oxygen desaturation index over the course of high altitude exposure during 2 sojourns at 5050 m compared to low altitude
Apnea-/hypopnea index measured by respiratory polygraphy	first sojourn at 5050 m, night 1, 6; second sojourn at 5050 m, night 1, 6; low altitude sojourn at 520 m, night 1	Change in apnea-/hypopnea index over the course of high altitude exposure during 2 sojourns at 5050 m compared to low altitude

Trial Locations

Locations (1)

University of Zurich; 🇨🇭 Zurich, Switzerland