The Psychophysiological Effect of Simulated and Terrestrial Altitude

NCT04075565 | Completed Results

• 1 other identifier: 2019-00504
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 3

Brief Summary

The aim of this study is to compare the psychophysiological effects of terrestrial altitude with a normobaric, hypoxic situation.

Conditions

Altitude Sickness; Mountain Sickness; Hypoxia, Altitude; Hypoxia; Altitude Hypoxia; Altitude

Keywords

hypoxia; altitude; physiology; cognition

Outcome Measures

Primary Outcomes (8)

• Oxygenation of the Brain

  Brain oxygen saturation is measured non-invasively using a deep tissue oxygenation monitor (moorVMS-NIRS, moor instruments, www.moor.co.uk). For this purpose, adhesive electrodes are applied over the muscle and the forehead. This measurement is taken during the baseline measurements, and during the cognitive performance test. This outcome measure reports the change from baseline for the oxygenation of the brain.

  Baseline (participants seated for 15 minutes) and during the cognitive performance under normobaric hypoxia, hypobaric hypoxia, and control conditions (mean over time)

• Oxygenation of the Blood

  The oxygen saturation of the blood (SpO2) is measured with a portable pulse oximeter with finger clip probe (Nonin 7500, Nonin medical B.V., Plymouth, USA). This measurement is taken during the baseline measurements and after the step-up task. This outcome measure reports the change from baseline for the oxygenation of the blood.

  Continuously during the 15-minute seated baseline period before each trial (mean over 15min) and at the end of the step-up test (point measurement)

• Mean Arterial Pressure

  Blood pressure was measured using an automated sphygmomanometer monitor from the left brachial artery. MAP was calculated using the following formula: MAP = diastolic blood pressure + (systolic blood pressure-diastolic blood pressure) / 3.

  At the end of the 15-minute baseline seated period before each trial and at the end of the 3-minute submaximal step-test (Point measurements)

• Heart Rate

  The heart rate is measured using a pulse belt and an additional 2-point ECG (Actiheart, Camntech Ltd., Cambridge, UK). This measurement is taken during the baseline measurements and after the step-up task. This outcome measure reports the change from baseline for the heart rate.

  at baseline and the end of the submaximal step test (point measurements)

• Concentration of Blood Lactate

  Lactate measurements are performed by capillary blood measurement. This measurement is taken during the baseline measurements and after the step-up task.

  at the end of 15min baseline period and the end of the step-up test (point measurements)

• Sleep Quality

  Sleep quality of the night before the experimental day was assessed using the validated and reliable GSQS, consisting of a 16-item true or false questionnaire. GSQS scores ranged from 0 to 16 whereas higher scores indicated lower subjective sleep quality.

  Before the cognitive performance test (point measurement)

• Altitude Sickness

  Altitude sickness is measured with "Lake Louis acute mountain sickness scale", choosing the most appropriate answer from 5 questions. Questions range from 0 (=no symptoms) to 4 (=severe symptoms). LLAMS symptoms were assessed at the end of each experimental measurement.

  After performing the 3-min step-test (point measurment)

• Concentration of Salivary Cortisol

  Salivary cortisol was assessed from the n = 10 female participants to assess the daily stress level after each experimental day. Through a straw, 3mL of saliva was collected and stored in a refrigerator until the analyses were performed the next day using the enzyme-linked immunosorbent assay (ELISA) method.

  After each experimental day, in the evening between 8:30 PM and midnight, measured once before participants went to bed (point measurment)

Study Arms (3)

Simulated altitude

ACTIVE COMPARATOR

The participants are exposed to simulated altitude in a normobaric situation.

Behavioral: Cloud 9

Terrestrial altitude

EXPERIMENTAL

The participants are exposed to terrestrial altitude in a hypobaric situation.

Behavioral: Terrestrial altitude

Control

NO INTERVENTION

the participants are exposed to a normoxic and normobaric environment.

Interventions

Terrestrial altitude BEHAVIORAL

Terrestrial altitude: The volunteers are in an SAC hut at an altitude of 3000 m. By means of this exposure the psychophysiological effect under hypobaric and hypoxic conditions is determined. The subjects spend the night in this SAC hut and the measurements are repeated the next day.

Terrestrial altitude

Cloud 9 BEHAVIORAL

Cloud 9 is a solid, certified product that complies with European Directives on Electromagnetic Compatibility, Machine Directive, Air Pressure Equipment and Low Voltage Equipment (89/336 / EEC, 91/368 / CEE, 93/68 / CEE, 97/23 / EC, EN61010-1 All directives are in writing in the Supplements to this Ethics Application. Simulated height: The subjects are in the laboratory of our institution and are connected to the Cloud 9 by means of a mask. Subjects are exposed to a simulated altitude of 3530m under normobaric conditions. By means of this intervention the psychophysiological effect under normobaric and hypoxic conditions is determined.

Simulated altitude

Eligibility Criteria

• Age: 18 Years - 50 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy, adults aged 18 to 50 years
• No cardiovascular disease and / or surgery
• no surgery on the cardiovascular system.
• No current injuries and / or pain
• Regular and adequate sleep
• No terrestrial altitude of 1000 m exceeded last month (including flights)
• No form of hypoxia exposed last month

You may not qualify if:

• Age over 50 years
• current injuries of any kind and / or pain
• Acute and / or chronic pain conditions Known general diseases (e.g., diabetes mellitus)
• fear of hypoxia
• fear of heights or sensitivity to terrestrial altitude
• Regular use of medicines (also bought by yourself), except for contraceptives
• Cardiovascular diseases or abnormalities
• Anomalies of the blood analysis or ECG
• Psychological disorders
• pregnancy / lactation

Sponsors & Collaborators

• University of Applied Sciences and Arts of Southern Switzerland: lead
• University of Portsmouth: collaborator
• Vrije Universiteit Brussel: collaborator

Study Sites (3)

Fachhochschule Südschweiz

Landquart, Kanton Graubünden, 7302, Switzerland

Location

University of Applied Sciences and Arts of Southern Switzerland (SUPSI)

Landquart, Kanton Graubünden, 7302, Switzerland

Location

Fachhochschule Südschweiz

Landquart, 7302, Switzerland

Location

Related Publications (1)

• Hohenauer E, Freitag L, Costello JT, Williams TB, Kung T, Taube W, Herten M, Clijsen R. The effects of normobaric and hypobaric hypoxia on cognitive performance and physiological responses: A crossover study. PLoS One. 2022 Nov 10;17(11):e0277364. doi: 10.1371/journal.pone.0277364. eCollection 2022.

  PMID: 36355846 RESULT

Related Links

• fullversion of publication

MeSH Terms

Conditions

Hypoxia; Altitude Sickness

Condition Hierarchy (Ancestors)

Signs and Symptoms, Respiratory; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Respiration Disorders; Respiratory Tract Diseases

Results Point of Contact

• Title: Dr Erich Hohenauer
• Organization: Rehabilitation and Exercise Science Laboratory (RES lab), University of Applied Sciences and Arts of Southern Switzerland (SUPSI)

erich.hohenauer@supsi.ch

0041 81 300 01 75

Study Officials

• Ron Clijsen, PhD

  University of Applied Sciences and Arts of Southern Switzerland (SUPSI)

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: INVESTIGATOR
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: The study design is a crossover design.

Study Record Dates

• First Submitted: August 7, 2019
• First Posted: August 30, 2019
• Study Start: June 24, 2019
• Primary Completion: March 31, 2021
• Study Completion: April 30, 2022
• Last Updated: February 19, 2026
• Results First Posted: February 19, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

CH (3)