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

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

• 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

• Mean nocturnal SpO2 after 7 days at sea level [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

• Time spent with low SpO2 after 7 days at sea level [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
• Apnoea-Hypopnoea-Index AHI after 7 days at sea level [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
• Oxygen-Desaturation-Index ODI after 7 days at sea level [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
• Nocturnal cardiovascular autonomic control after 7 days at sea level [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
• Acclimatization-Effect of mean nocturnal SpO2 at sea level [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
• Acclimatization-Effect of time spent with low SpO2 at sea level [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
• Acclimatization-Effect of Apnoea-Hypopnoea-Index AHI at sea level [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
• Acclimatization-Effect of Oxygen-Desaturation-Index ODI at sea level [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
• Acclimatization-Effect of nocturnal cardiovascular autonomic control at sea level [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
• Mean nocturnal SpO2 after re-ascent to 2850m [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
• Time spent with low SpO2 after re-ascent to 2850m [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
• Apnoea-Hypopnoea-Index AHI after re-ascent to 2850m [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
• Oxygen-Desaturation-Index ODI after re-ascent to 2850m [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
• Nocturnal cardiovascular autonomic control after re-ascent to 2850m [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
• Mean nocturnal SpO2 pre-descent and after re-ascent (2850m) [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
• Time spent with low SpO2 pre-descent and after re-ascent (2850m) [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
• Apnoea-Hypopnoea-Index AHI pre-descent and after re-ascent (2850m) [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
• Oxygen-Desaturation-Index ODI pre-descent and after re-ascent (2850m) [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
• Nocturnal cardiovascular autonomic control pre-descent and after re-ascent (2850m) [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

Sex: All, ages: 18 Years to 80 Years, accepts healthy volunteers

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

• Silvia Ulrich, Principal investigator, University Hospital Zurich, Departement of Pulmonology
• Rodrigo Hoyos, Principal investigator, Hospital Carlos Andrade Marin of Quito, Ecuador