Effect of Supplemental Oxygen Therapy on Neurocognitive Performance in Healthy Highlanders (SPIRIT_1)

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).

Study Overview

• Status: Not yet recruiting
• Conditions: Neurocognition
• Intervention / Treatment: Drug: Supplemental oxygen therapy; Other: Sham intervention

• Study Type: Interventional
• Enrollment (Estimated): 50
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Michael Furian, Prof. Dr.; Phone Number: +41794037586; Email: michael.furian@usz.ch
• Study Contact Backup: Name: Edith M Schneider, Dr.; Email: edith.schneidergasser@usz.ch

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

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

Exclusion Criteria:

• 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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: SOT followed by Sham intervention; 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 therapy; 5 L/min supplemental oxygen therapy administered through nasal canula.; Other: Sham intervention; 5 L/min sham intervention administered through nasal canula.
Sham Comparator: Sham intervention followed by SOT; 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 therapy; 5 L/min supplemental oxygen therapy administered through nasal canula.; Other: Sham intervention; 5 L/min sham intervention administered through nasal canula.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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 Outcome Measures

Outcome Measure	Measure Description	Time Frame
Trail making test performance	The difference in the trial making test A performance between SOT and Sham intervention.	Comparison between SOT and sham after 15 minutes intervention
Stroop test performance	The difference in the stroop test performance between SOT and Sham intervention.	Comparison between SOT and sham after 15 minutes intervention
Digit Span test performance	The difference in the digit span test performance between SOT and Sham intervention.	Comparison between SOT and sham after 15 minutes intervention
Go / No-Go test performance	The difference in the Go / No-Go test performance between SOT and Sham intervention.	Comparison between SOT and sham after 15 minutes intervention
N-back test performance	The difference in the n-back test performance between SOT and Sham intervention.	Comparison between SOT and sham after 15 minutes intervention
Task Switching Cued test performance	The difference in the task switching cued test performance between SOT and Sham intervention.	Comparison between SOT and sham after 15 minutes intervention
Flanker test performance	The difference in the Flanker test performance between SOT and Sham intervention.	Comparison between SOT and sham after 15 minutes intervention
Corsi Span test performance	The difference in the Corsi span test performance between SOT and Sham intervention.	Comparison between SOT and sham after 15 minutes intervention

Collaborators and Investigators

• Sponsor: University of Zurich
• Collaborators: National Center of Cardiology and Internal Medicine named after academician M.Mirrakhimov
• Investigators: Principal Investigator: Michael Furian, University of Zurich; Principal Investigator: Edith M Schneider, Dr., University of Zurich

Study record dates

Study Major Dates

• Study Start (Estimated): June 18, 2026
• Primary Completion (Estimated): July 31, 2026
• Study Completion (Estimated): July 31, 2026

Study Registration Dates

• First Submitted: June 3, 2026
• First Submitted That Met QC Criteria: June 10, 2026
• First Posted (Actual): June 16, 2026

Study Record Updates

• Last Update Posted (Actual): June 16, 2026
• Last Update Submitted That Met QC Criteria: June 10, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Hypoxia; Altitude; Supplemental oxygen therapy
• Additional Relevant MeSH Terms: Signs and Symptoms, Respiratory; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Hypoxia; Inorganic Chemicals; Elements; Chalcogens; Gases; Oxygen
• Other Study ID Numbers: SPIRIT_1

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No