Effect of High Altitude
Conditions
Keywords
High altitude, Cerebral autoregulation, Transfer function analysis
Brief summary
Prospective interventional trial in lowlanders evaluating the effect of acute exposure, acclimatization and re-exposure to high altitude on cerebral autoregulation
Detailed description
Baseline measurements 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 8 nights and they will be spend the days (6-8 h daily) at the telescope station at 5050 m while undergoing testing as described above at the first and the last day at 5050m. 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.
Interventions
OTHERaltitude exposure
altitude exposure
Sponsors
University of Calgary
University of Zurich
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* Born, raised and currently living \<800m * No overnight stay at altitudes \>1500 m 4 weeks before the study
Exclusion criteria
* Previous altitude intolerance to altitude \<3000 m * Pregnancy * Health impairment, which requires regular treatment
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Coherence between middle cerebral artery blood flow velocity and systemic blood pressure as measure of cerebral autoregulation. | day 1; day 2 first cycle | Change in magnitude of the coefficient of coherence between blood flow velocity in the middle cerebral artery measured by transcranial ultrasound Doppler and systemic blood pressure at day 2 (5050 m) vs. day 1 (520 m) of the first cycle |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Coherence between middle cerebral artery blood flow velocity and systemic blood pressure as measure of cerebral autoregulation. | day 1; day 7 first cycle | Change in magnitude of the coefficient of coherence between blood flow velocity in the middle cerebral artery measured by transcranial ultrasound Doppler and systemic blood pressure at day 7 (5050 m) vs. day 1 (520 m) of the first cycle. |
Countries
Switzerland
Outcome results
None listed