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HealthyNCT07801950

Sleep-Assessment in Patients Between High Altitude HA vs. Sea Level LA in Healthy Individuals H

A study testing Descent from 2850m to sea level and re-ascent back to 2850m in people with Healthy and Healthy Adult, run by Silvia Ulrich Somaini at 1 site in Switzerland.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
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Trial summary

To study the effect of relocation from high altitude (Quito Ecuador: 2850m) to sea level on sleeping parameters by polygraphy in healthy individuals, who live permanently >2600m. Read more about this study

Who is it for?
Ages 18 to 80 yearsHealthy volunteers can take part
Conditions the study is for
Healthy, Healthy Adult, High Altitude Effects
What is being tested?
Descent from 2850m to sea level and re-ascent back to 2850m
Could I receive a placebo?
No, everyone receives an active treatment
How many people
14 participants
Where
1 siteSwitzerland
Study dates
25 Sep 2026to 31 Dec 2026
Phase
Interventional
Are there results?
Not yet: the study is under way

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 80 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Adults aged 18-80 years and of all genders
  • Permanent residence > 2600 m
  • healthy: no self-perceived cardiopulmonary disease limiting daily activities
  • written informed consent to participate in the study

Who cannot join

  • Age <18 years or >80 years
  • Participants who cannot follow the study investigations
  • Participants permanently living < 2600m.
  • Participants who traveled and stayed overnight at altitudes <2000 m in the past 4 weeks.
  • any self-perceived cardiopulmonary disease limiting daily activities

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Silvia Ulrich, Prof. Dr. med. contact

+41442552220

silvia.ulrich@usz.ch

Michael Furian, Prof. Dr. sc. ETH contact

+41442552220

Switzerland1 site

  • University Hospital of Zurich

    Zurich, 8091

Other trials in Switzerland

About this study

Official title: Effect of a One-week Descent From 2850m to Sea Level and Re-ascent in Patients With Pulmonary Arterial Hypertension and Healthy Controls Permanently Living > 2600m on Pulmonary Hemodynamics, Exercise Capacity, Blood Oxygenation, Sleep Disordered Breathing and Further Outcomes

To study the effect of relocation from high altitude (Quito Ecuador: 2850m) to sea level on sleeping parameters by polygraphy in healthy individuals, who live permanently >2600m.

Read the detailed description

The aim of this research is to investigate sleeping parameters by polygraphy before and after relocation (high altitude near their living altitude vs. sea level) in healthy individuals, who permanently live at high altitude over 2600m

Being tested
Descent from 2850m to sea level and re-ascent back to 2850m
Keywords
Health, High Altitude, Polygraphy, Sleep, Sleep disordered breathing
Medical subject headings
Altitude Sickness, Sleep Apnea Syndromes

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Descent from 2850m to sea level and re-ascent back to 2850mBehavioural

    Descent from 2850m to sea level with a stay for 7 days and re-ascent back to 2850m

Study groups in NCT07801950
Study groupRoleWhat they receive
Sleep-parameters at 2850m and at sea levelExperimentalAssessment of sleep-parameters by polygraphy in healthy individuals at 2850m (pre-descent and after re-ascent) and at sea level in between
Receives: Behavioral: Descent from 2850m to sea level and re-ascent back to 2850m

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Mean nocturnal SpO2 after 7 days at sea level

    Difference/change in mean nocturnal SpO2 between 2850m and Night 7 at sea level in healthy individuals

    Measured: From high altitude (2850m) to night 7 at sea level

Secondary outcomes (19)

  1. Time spent with low SpO2 after 7 days at sea level

    Difference/change in time spent with low SpO2 (< 90% and < 80%) between 2850m and night 7 at sea level in healthy individuals

    Measured: From high altitude (2850m) to night 7 at sea level

  2. Apnoea-Hypopnoea-Index AHI after 7 days at sea level

    Difference/change in nocturnal apnoea-hypopnoea-index between 2850m and night 7 at sea level in healthy individuals

    Measured: From high altitude (2850m) to night 7 at sea level

  3. Oxygen-Desaturation-Index ODI after 7 days at sea level

    Difference/change in nocturnal Oxygen-Desaturation-Index ODI between 2850m and night 7 at sea level in healthy individuals

    Measured: From high altitude (2850m) to night 7 at sea level

  4. Nocturnal cardiovascular autonomic control after 7 days at sea level

    Difference/change in nocturnal cardiovascular autonomic control by heart rate (variability) between 2850m and night 7 at sea level in healthy individuals

    Measured: From high altitude (2850m) to night 7 at sea level

  5. Acclimatization-Effect of mean nocturnal SpO2 at sea level

    Difference/change in mean nocturnal SpO2 at night 1 and night 7 within a stay at sea level of 7 days (after relocation from high altitude) in healthy individuals

    Measured: From Night 1 to Night 7 at sea level

  6. Acclimatization-Effect of time spent with low SpO2 at sea level

    Difference/change in time spent with low SpO2 (< 90% and < 80%) at night 1 and night 7 within a stay at sea level of 7 days (after relocation from high altitude) in healthy individuals

    Measured: From Night 1 to Night 7 at sea level

  7. Acclimatization-Effect of Apnoea-Hypopnoea-Index AHI at sea level

    Difference/change in nocturnal apnoea-hypopnoea-index at night 1 and night 7 within a stay at sea level of 7 days (after relocation from high altitude) in healthy individuals

    Measured: From Night 1 to Night 7 at sea level

  8. Acclimatization-Effect of Oxygen-Desaturation-Index ODI at sea level

    Difference/change in nocturnal oxygen-desaturation-index at night 1 and night 7 within a stay at sea level of 7 days (after relocation from high altitude) in healthy individuals

    Measured: From Night 1 to Night 7 at sea level

  9. Acclimatization-Effect of nocturnal cardiovascular autonomic control at sea level

    Difference/change in nocturnal cardiovascular autonomic control by heart rate (variability) at night 1 and night 7 within a stay at sea level of 7 days (after relocation from high altitude) in healthy individuals

    Measured: From Night 1 to Night 7 at sea level

  10. Mean nocturnal SpO2 after re-ascent to 2850m

    Difference/change in mean nocturnal SpO2 between sea level (after one-week stay) and night after re-ascent to 2850m in healthy individuals

    Measured: From Night 7 at sea level to night after reascent (time frame of 3 days)

  11. Time spent with low SpO2 after re-ascent to 2850m

    Difference/change in time spent with low SpO2 (< 90% and < 80%) between sea level (after one-week stay) and night after re-ascent to 2850m in healthy individuals

    Measured: From Night 7 at sea level to night after re-ascent (time frame of 3 days)

  12. Apnoea-Hypopnoea-Index AHI after re-ascent to 2850m

    Difference/change in nocturnal apnoea-hypopnoea-index between sea level (after one-week stay) and night after re-ascent to 2850m in healthy individuals

    Measured: From Night 7 at sea level to night after re-ascent (time frame of 3 days)

  13. Oxygen-Desaturation-Index ODI after re-ascent to 2850m

    Difference/change in nocturnal oxygen-desaturation-index between sea level (after one-week stay) and night after re-ascent to 2850m in healthy individuals

    Measured: From Night 7 at sea level to night after re-ascent (time frame of 3 days)

  14. Nocturnal cardiovascular autonomic control after re-ascent to 2850m

    Difference/change in nocturnal cardiovascular autonomic control by heart rate (variability) between sea level (after one-week stay) and night after re-ascent to 2850m in healthy individuals

    Measured: From Night 7 at sea level to night after re-ascent (time frame of 3 days)

  15. Mean nocturnal SpO2 pre-descent and after re-ascent (2850m)

    Difference/change in mean nocturnal SpO2 between the night at 2850m prior to the descent to sea level (stay of 7 days at sea level in between) and the night at 2850m after re-ascent in healthy individuals

    Measured: From the night at 2850m prior to the descent, stay at sea level of one week in between, to the night after re-ascent to 2850m (time frame approximately 11 days)

  16. Time spent with low SpO2 pre-descent and after re-ascent (2850m)

    Difference/change in time spent with low SpO2 (< 90% and < 80%) between the night at 2850m prior to the descent to sea level (stay of 7 days at sea level in between) and the night at 2850m after re-ascent in healthy individuals

    Measured: From the night at 2850m prior to the descent, stay at sea level of one week in between, to the night after re-ascent to 2850m (time frame approximately 11 days)

  17. Apnoea-Hypopnoea-Index AHI pre-descent and after re-ascent (2850m)

    Difference/change in nocturnal apnoea-hypopnoea-index between the night at 2850m prior to the descent to sea level (stay of 7 days at sea level in between) and the night at 2850m after re-ascent in healthy individuals

    Measured: From the night at 2850m prior to the descent, stay at sea level of one week in between, to the night after re-ascent to 2850m (time frame approximately 11 days)

  18. Oxygen-Desaturation-Index ODI pre-descent and after re-ascent (2850m)

    Difference/change in nocturnal oxygen-desaturation-index between the night at 2850m prior to the descent to sea level (stay of 7 days at sea level in between) and the night at 2850m after re-ascent in healthy individuals

    Measured: From the night at 2850m prior to the descent, stay at sea level of one week in between, to the night after re-ascent to 2850m (time frame approximately 11 days)

  19. Nocturnal cardiovascular autonomic control pre-descent and after re-ascent (2850m)

    Difference/change in nocturnal cardiovascular autonomic control by heart rate (variability) between the night at 2850 prior to the descent to sea level (stay of 7 days at sea level in between) and the night at 2850m after re-ascent in healthy individuals

    Measured: From the night at 2850m prior to the descent, stay at sea level of one week in between to the night after re-ascent to 2850m (time frame approximately 11 days)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted3 Sep 2026
  2. Study start25 Sep 2026 (estimated)
  3. Primary completion4 Oct 2026 (estimated)
  4. Study completion31 Dec 2026 (estimated)

Resources

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
Supportive care
Allocation
Not applicable
Intervention model
Single group
Model description
Healthy individuals living permanently \> 2600m around Quito (Ecuador) will be assessed at 2850m, after relocation to sea level for 7 days and after re-ascent
Masking
None (open label)
Enrolment
14 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07801950
Sponsor's protocol ID
Ec_HAvsLA_sleep_H
Status last verified
Aug 2026
First submitted
17 Aug 2026
Last updated
3 Sep 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: Data will be provided upon request and based on a clear intention reviewed by an ethical review board.

Questions about this trial

What is this clinical trial studying?

A study testing Descent from 2850m to sea level and re-ascent back to 2850m in people with Healthy and Healthy Adult, run by Silvia Ulrich Somaini 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 4 inclusion and 5 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: opening soon, as of the sponsor's last update on 3 Sep 2026. 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?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Silvia Ulrich, Prof. Dr. med. (+41442552220, silvia.ulrich@usz.ch), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Mean nocturnal SpO2 after 7 days at sea level (time frame: From high altitude (2850m) to night 7 at sea level). 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 NCT07801950.

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 3 Sep 2026.

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