Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
| Name | Class |
|---|---|
| University of Calgary | OTHER |
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Prospective interventional trial in lowlanders evaluating the effect of acute exposure, acclimatization and re-exposure of high altitude on nocturnal breathing pattern.
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.
Not provided
Not provided
Not provided
Not provided
| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Altitude exposure | Experimental | Acute high altitude exposure followed by 8 day acclimatization and re-exposure after 6 days at low altitude |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Altitude exposure | Other | Altitude exposure |
|
| Measure | Description | Time Frame |
|---|---|---|
| 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 | first sojourn at 5050 m, night 1, 6; second sojourn at 5050 m, night 1, 6; low altitude sojourn at 520 m, night 1 |
| Measure | Description | Time Frame |
|---|---|---|
| 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 | 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 |
Not provided
Inclusion Criteria:
Exclusion Criteria:
Not provided
Not provided
Not provided
Not provided
Not provided
| Name | Affiliation | Role |
|---|---|---|
| Konrad E Bloch, MD | University of Zurich | Study Chair |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| University of Zurich | Zurich | 8091 | Switzerland |
| PubMed Identifier | Type | Citation | Retractions |
|---|---|---|---|
| 40234589 | Derived | 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. |
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Change in oxygen desaturation index over the course of high altitude exposure during 2 sojourns at 5050 m compared to low altitude |
| 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 | first sojourn at 5050 m, day 2, 7; second sojourn at 5050 m, day 2,7; low altitude sojourn at 520 m, day 2 |