NCT07651917

Brief Summary

Exposure to high altitudes, defined as locations above 2500 m, has been shown to cause cognitive alternations due to reduced blood oxygenation (SpO2). However, it remains to be determined whether cognitive changes are present in highlanders living at moderate altitudes (2500 m) and whether cognitive alterations are reversible with supplemental oxygen therapy (SOT).

Trial Health

35
At Risk

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Trial has exceeded expected completion date
Enrollment
50

participants targeted

Target at P25-P50 for phase_4

Timeline
Completed

Started Jun 2026

Shorter than P25 for phase_4

Status
not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

June 3, 2026

Completed
13 days until next milestone

First Posted

Study publicly available on registry

June 16, 2026

Completed
2 days until next milestone

Study Start

First participant enrolled

June 18, 2026

Completed
1 month until next milestone

Primary Completion

Last participant's last visit for primary outcome

July 31, 2026

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

July 31, 2026

Completed
Last Updated

June 16, 2026

Status Verified

June 1, 2026

Enrollment Period

1 month

First QC Date

June 3, 2026

Last Update Submit

June 10, 2026

Conditions

Neurocognition

Keywords

HypoxiaAltitudeSupplemental oxygen therapy

Outcome Measures

Primary Outcomes (1)

  • Psychomotor vigilance reaction time

    The difference in the reaction time during a 10-minute psychomotor vigilance test between SOT and Sham intervention.

    Comparison between SOT and sham after 15 minutes intervention

Secondary Outcomes (8)

  • Trail making test performance

    Comparison between SOT and sham after 15 minutes intervention

  • Stroop test performance

    Comparison between SOT and sham after 15 minutes intervention

  • Digit Span test performance

    Comparison between SOT and sham after 15 minutes intervention

  • Go / No-Go test performance

    Comparison between SOT and sham after 15 minutes intervention

  • N-back test performance

    Comparison between SOT and sham after 15 minutes intervention

  • +3 more secondary outcomes

Study Arms (2)

SOT followed by Sham intervention

ACTIVE COMPARATOR

5L /min supplemental oxygen therapy through a nasal canula will be administered to the participants. The intervention will start 5 minutes before the neurocognitive assessments and will be administered throughout the assessment. After \>4 hours of washout, the participants will repeat the neurocognitive assessments with 5 L/min sham intervention (room air).

Drug: Supplemental oxygen therapyOther: Sham intervention

Sham intervention followed by SOT

SHAM COMPARATOR

5L /min sham intervention (room air) through a nasal canula will be administered to the participants. The intervention will start 5 minutes before the neurocognitive assessments and will be administered throughout the assessment. After \>4 hours of washout, the participants will repeat the neurocognitive assessments with 5 L/min supplemental oxygen therapy.

Drug: Supplemental oxygen therapyOther: Sham intervention

Interventions

Sham interventionOTHER

5 L/min sham intervention administered through nasal canula.

SOT followed by Sham interventionSham intervention followed by SOT
Supplemental oxygen therapyDRUG

5 L/min supplemental oxygen therapy administered through nasal canula.

SOT followed by Sham interventionSham intervention followed by SOT

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Signed written consent
  • Age \>18
  • Kyrgyz ethnicity
  • Born, raised and living at approximately 2500 m
  • Native or fluent in Russian language

You may not qualify if:

  • Severe disease such as unstable hypertension, coronary heart disease, pulmonary diseases, others.
  • Regular use of medication that interfere with sleep or breathing such as benzodiazepines, opioids, acetazolamide
  • Heavy smoking of \>20 cigarettes per day
  • Not able to read or adhere to the study protocol

Contact the study team to confirm eligibility.

Sponsors & Collaborators

MeSH Terms

Conditions

Hypoxia

Interventions

Oxygen

Condition Hierarchy (Ancestors)

Signs and Symptoms, RespiratorySigns and SymptomsPathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

ChalcogensElementsInorganic ChemicalsGases

Study Officials

  • Michael Furian

    University of Zurich

    PRINCIPAL INVESTIGATOR

  • Edith M Schneider, Dr.

    University of Zurich

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Michael Furian, Prof. Dr.

CONTACT

+41794037586michael.furian@usz.ch

Edith M Schneider, Dr.

CONTACT

edith.schneidergasser@usz.ch

Study Design

Study Type
interventional
Phase
phase 4
Allocation
RANDOMIZED
Masking
SINGLE
Who Masked
PARTICIPANT
Purpose
TREATMENT
Intervention Model
CROSSOVER
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

June 3, 2026

First Posted

June 16, 2026

Study Start

June 18, 2026

Primary Completion

July 31, 2026

Study Completion

July 31, 2026

Last Updated

June 16, 2026

Record last verified: 2026-06