Effect of High AltitudeNCT02730143
Effect of High Altitude Exposure, Acclimatization and Re-exposure on Nocturnal Breathing Pattern in Lowlanders
A study testing Altitude exposure in people with Effect of High Altitude, run by University of Zurich at 1 site in Switzerland.
Trial summary
Prospective interventional trial in lowlanders evaluating the effect of acute exposure, acclimatization and re-exposure of high altitude on nocturnal breathing pattern. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Effect of High Altitude
- What is being tested?
- Altitude exposure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 21 participants
- Where
- 1 siteSwitzerland
- Study dates
- 4 Apr 2016to 7 May 2016
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- born, raised and currently living <800m
- No overnight stay at altitudes >1500 m 4 weeks before the study
Who cannot join
- Previous altitude intolerance to altitude <3000 m
- Pregnancy
- Health impairment, which requires regular treatment
Trial locations and contacts
1 site in 1 country.
About this study
Prospective interventional trial in lowlanders evaluating the effect of acute exposure, acclimatization and re-exposure of high altitude on nocturnal breathing pattern.
Read the 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.
- Conditions
- Effect of High Altitude
- Being tested
- Altitude exposure
- Keywords
- Altitude, Nocturnal breathing pattern
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Altitude exposureOther
Altitude exposure
| Study group | Role | What they receive |
|---|---|---|
| Altitude exposure | Experimental | Acute high altitude exposure followed by 8 day acclimatization and re-exposure after 6 days at low altitude Receives: Other: Altitude exposure |
What is being measured
The primary outcome is the main question the study is designed to answer.
Mean nocturnal oxygen saturation measured by pulse oximetry
Change in mean nocturnal oxygen saturation over the course of high altitude exposure during 2 sojourns at 5050 m compared to low altitude
Measured: first sojourn at 5050 m, night 1, 6; second sojourn at 5050 m, night 1, 6; low altitude sojourn at 520 m, night 1
Secondary outcomes (3)
Apnea-/hypopnea index measured by respiratory polygraphy
Change in apnea-/hypopnea index over the course of high altitude exposure during 2 sojourns at 5050 m compared to low altitude
Measured: first sojourn at 5050 m, night 1, 6; second sojourn at 5050 m, night 1, 6; low altitude sojourn at 520 m, night 1
Oxygen desaturation index measured by respiratory polygraphy
Change in oxygen desaturation index over the course of high altitude exposure during 2 sojourns at 5050 m compared to low altitude
Measured: first sojourn at 5050 m, night 1, 6; second sojourn at 5050 m, night 1, 6; low altitude sojourn at 520 m, night 1
Acute mountain sickness measured by the Environmental Symptom questionnaire cerebral score (AMSc)
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
Measured: first sojourn at 5050 m, day 2, 7; second sojourn at 5050 m, day 2,7; low altitude sojourn at 520 m, day 2
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Apr 2016 (estimated)
- Study start4 Apr 2016
- Primary completion7 May 2016
- Study completion7 May 2016
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Effect of High AltitudeStudies of the same condition, open and under way.
- More trials run by University of ZurichThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 21 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Zurich
- Sponsor type
- University, hospital or other
- Collaborators
- University of Calgary
- Responsible party
- Sponsor
- Investigators
- Konrad E Bloch, MD, Study chair, University of Zurich
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02730143
- Sponsor's protocol ID
- REB15-2709_V1
- Status last verified
- Nov 2018
- First submitted
- 31 Mar 2016
- Last updated
- 13 Nov 2018
- Results posted
- No
- Data monitoring committee
- No
- Individual data sharing
- No
Publications
Waldner NF, Hartmann SE, Muralt L, Lichtblau M, Bader PR, Rawling JM, Lopez I, Ulrich S, Poulin MJ, Bloch KE, Furian M. Oxygen saturation and acute mountain sickness during repeated altitude exposures simulating high-altitude working schedules. Sci Rep. 2025 Apr 15;15(1):12987. doi: 10.1038/s41598-025-97554-7.
PubMed 40234589
Study at a glance
From the registry record, last updated by the sponsor on 13 Nov 2018. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of High Altitude Exposure, Acclimatization and Re-exposure on Nocturnal Breathing Pattern in Lowlanders
- ClinicalTrials.gov ID
- NCT02730143
- Acronym / sponsor ID
- REB15-2709_V1
- Conditions
- Effect of High Altitude
- Keywords
- Altitude, Nocturnal breathing pattern
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 21 participants (actual)
- Lead sponsor
- University of ZurichUniversity, hospital or other
- Collaborators
- University of Calgary
- Study start
- 4 Apr 2016 (actual)
- Primary completion
- 7 May 2016 (actual)
- Study completion
- 7 May 2016 (actual)
- First posted
- 6 Apr 2016 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 design
- Primary purpose
- Prevention
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Altitude exposure | Experimental | Other: Altitude exposureAcute high altitude exposure followed by 8 day acclimatization and re-exposure after 6 days at low altitude |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- born, raised and currently living <800m
- No overnight stay at altitudes >1500 m 4 weeks before the study
Key exclusion criteria (3 listed)
- Previous altitude intolerance to altitude <3000 m
- Pregnancy
- Health impairment, which requires regular treatment
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Altitude exposureAltitude exposure | Other | Altitude exposure |
Primary outcome
Mean nocturnal oxygen saturation measured by pulse oximetry
Time frame: 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
3 secondary outcomes
Apnea-/hypopnea index measured by respiratory polygraphy
Time frame: first sojourn at 5050 m, night 1, 6; second sojourn at 5050 m, night 1, 6; low altitude sojourn at 520 m, night 1
Oxygen desaturation index measured by respiratory polygraphy
Time frame: first sojourn at 5050 m, night 1, 6; second sojourn at 5050 m, night 1, 6; low altitude sojourn at 520 m, night 1
Acute mountain sickness measured by the Environmental Symptom questionnaire cerebral score (AMSc)
Time frame: first sojourn at 5050 m, day 2, 7; second sojourn at 5050 m, day 2,7; low altitude sojourn at 520 m, day 2
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Nov 2018.
- Derived from this study: PubMed 40234589Waldner NF, Hartmann SE, Muralt L, Lichtblau M, Bader PR, Rawling JM, Lopez I, Ulrich S, Poulin MJ, Bloch KE, Furian M. Oxygen saturation and acute mountain sickness during repeated altitude exposures simulating high-altitude working schedules. Sci Rep. 2025 Apr 15;15(1):12987. doi: 10.1038/s41598-025-97554-7.
- Individual participant dataSharing planned: No
Related trials for Effect of High Altitude
Not yet recruiting
Assessment of Six-minute Walking Distance 6MWD Between High Altitude HA vs. Sea Level LA in Patients With Pulmonary Arterial Hypertension PAH
Pulmonary Arterial Hypertension (PAH), Pulmonary Vascular Disease
Not yet recruiting
Assessment of Lung Function (Lufu) at Sea Level LA vs. High Altitude HA in Healthy Individuals
Healthy, Healthy Adult
Not yet recruiting
Assessment of Lung Function (Lufu) at Sea Level LA vs. High Altitude HA in Patients With Pulmonary Arterial Hypertension PAH
Pulmonary Arterial Hypertension (PAH), Pulmonary Vascular Disease
Not yet recruiting
Assessment of Total Pulmonary Resistance sPAP/CO Between Sea Level LA vs. High Altitude HA After Re-ascent in Healthy Individuals
High Altitude, Healthy
Not yet recruiting
Assessment of Heart Rate Variability HRV During Descent DE From 2850m to Sea Level and During Re-ascent A From Sea Level to 2850m in Healthy Individuals H
Healthy, Healthy Adult
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Konrad E Bloch, MD study chair
University of Zurich
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Altitude exposure in people with Effect of High Altitude, run by University of Zurich at 1 site in Switzerland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 13 Nov 2018. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Mean nocturnal oxygen saturation measured by pulse oximetry (time frame: first sojourn at 5050 m, night 1, 6; second sojourn at 5050 m, night 1, 6; low altitude sojourn at 520 m, night 1). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02730143, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Nov 2018; AzTrials last refreshed its copy on 7 Nov 2026.