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NCT Number: NCT07801950

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

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.

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Key information

Conditions

Healthy Altitude Sickness Apnea Dyssomnias Healthy Adult High Altitude High Altitude Effects Nervous System Diseases Polygraphy Respiration Disorders Respiratory Tract Diseases Sleep Sleep Apnea Syndromes Sleep Disordered Breathing (SDB) Sleep Disorders, Intrinsic Sleep Wake Disorders

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University Hospital of Zurich

Zurich, 8091, Switzerland

About this study

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

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 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

Exclusion criteria

  • 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

Treatment and study plan

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

Behavioral

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

Primary outcomes

  1. Mean nocturnal SpO2 after 7 days at sea level

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

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

Secondary outcomes

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

    Time frame: From high altitude (2850m) to night 7 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

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

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

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

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

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

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

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

    Time frame: From high altitude (2850m) to night 7 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

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

    Time frame: From Night 1 to Night 7 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

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

    Time frame: From Night 1 to Night 7 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

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

    Time frame: From Night 1 to Night 7 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

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

    Time frame: From Night 1 to Night 7 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

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

    Time frame: From Night 1 to Night 7 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

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

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

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

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

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

    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

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

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

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

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

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

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

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

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

    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

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

    Time frame: 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)

    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

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

    Time frame: 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)

    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

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

    Time frame: 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)

    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

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

    Time frame: 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)

    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

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

    Time frame: 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)

    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

Study contacts

Contact information is provided by the study sponsor or research team.

Michael Furian, Prof. Dr. sc. ETH

CONTACT

+41442552220

Silvia Ulrich, Prof. Dr. med.

CONTACT

[email protected]

+41442552220

Sponsors and collaborators

Lead sponsor

Silvia Ulrich Somaini

Other

Registry information

Official study 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

Important dates

Study start
2026
Primary completion
2026
Study completion
2026
First posted
Sep 3, 2026
Registry last updated
Sep 3, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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