Effect of High Altitude Exposure, Acclimatization and Re-exposure on Sustained Attention in Lowlanders

Effect of High Altitude Exposure, Acclimatization and Re-exposure on Sustained Attention in Lowlanders

Prospective interventional trial in lowlanders evaluating the effect of acute exposure, acclimatization and re-exposure to high altitude on global cognitive function.

Baseline measurements will be performed in Santiago de Chile, 520 m, over the course of 3 days. Participants will then travel by commercial airline (2 h flight) and by bus (2 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 they will be spend the days (6 total; 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 7 day altitude sojourn participants will return to the Santiago area (520 m) for a 7 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.

Altitude Exposure Acute high altitude exposure followed by 8 day acclimatization and reexposure for 8 days after 6 days at low altitude

Acute high altitude exposure followed by 8 day acclimatization and re-exposure for 8 days after 6 days at low altitude

Low altitude sojourn at 520m (Baseline); first sojourn at 5050m Day 2, 7; second sojourn at 5050m Day 2, 7 (each sojourn cycle = 7 days)

Change in cognitive subdomains (visual memory, executive function, working memory and planning, attention, semantic/verbal memory, decision-making and response control) assessed by neuropsychological test battery

Change in cognitive subdomains (visual memory, executive function, working memory and planning, attention, semantic/verbal memory, decision-making and response control) measured across two cycles of altitude exposure, comparing 5050m to 520m

Low altitude sojourn at 520m (Baseline); first sojourn at 5050m Day 2, 7; second sojourn at 5050m Day 2, 7 (each sojourn cycle = 7 days)

Low altitude sojourn at 520m (Baseline); first sojourn at 5050m Day 2, 7; second sojourn at 5050m Day 2, 7 (each sojourn cycle = 7 days)

Inclusion Criteria: born, raised and currently living <1300m No overnight stays at altitudes >1500m 4 weeks before the study Exclusion Criteria: previous altitude intolerance <3000m pregnancy health impairment, which requires regular treatment