Trial Outcomes & Findings for The Psychophysiological Effect of Simulated and Terrestrial Altitude (NCT NCT04075565)
NCT ID: NCT04075565
Last Updated: 2026-02-19
Results Overview
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.
Recruitment status
COMPLETED
Study phase
NA
Target enrollment
20 participants
Primary outcome timeframe
at baseline and the end of the submaximal step test (point measurements)
Results posted on
2026-02-19
Participant Flow
This is a randomised crossover trials. The same 20 participants were tested in all conditions
Participant milestones
| Measure |
Experimental: Normobaric Normoxia, Normobaric Hypoxia and Then Hypobaric Hypoxia
Twenty healthy participants completed a cognitive performance test, followed by the modified Harvard-step protocol, in four environments: normobaric normoxia (NN; PiO2: 146.0±1.5mmHg), nor- mobaric hypoxia (NH; PiO2: 100.9±1.3mmHg), hypobaric hypoxia (HH) at the first day of ascent (HH1: PiO2 = 105.6±0.4mmHg) and HH after an overnight stay (HH2: PiO2 = 106.0±0.5mmHg).
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|---|---|
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Overall Study
STARTED
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20
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Overall Study
Normobaric Normoxia
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20
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Overall Study
Normobaric Hypoxia
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20
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Overall Study
Hypobaric Hypoxia First Day
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20
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Overall Study
Hypobaric Hypoxia After Overnight
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20
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Overall Study
COMPLETED
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20
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Overall Study
NOT COMPLETED
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0
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Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
This is a crossover study, using the same 10 women and 10 men (total n=20) in all conditions
Baseline characteristics by cohort
| Measure |
Experimental: Normobaric Normoxia, Normobaric Hypoxia and Then Hypobaric Hypoxia
n=20 Participants
Twenty healthy participants completed a cognitive performance test, followed by the modified Harvard-step protocol, in four environments: normobaric normoxia (NN; PiO2: 146.0±1.5mmHg), normobaric hypoxia (NH; PiO2: 100.9±1.3mmHg), hypobaric hypoxia (HH) at the first day of ascent (HH1: PiO2 = 105.6±0.4mmHg) and HH after an overnight stay (HH2: PiO2 = 106.0±0.5mmHg).
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|---|---|
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Age, Continuous
Females
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24.8 years
STANDARD_DEVIATION 5.1 • n=10 Participants • This is a crossover study, using the same 10 women and 10 men (total n=20) in all conditions
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Age, Continuous
Males
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30.3 years
STANDARD_DEVIATION 6.3 • n=10 Participants • This is a crossover study, using the same 10 women and 10 men (total n=20) in all conditions
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Sex: Female, Male
Female
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10 Participants
n=20 Participants
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Sex: Female, Male
Male
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10 Participants
n=20 Participants
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PRIMARY outcome
Timeframe: Baseline (participants seated for 15 minutes) and during the cognitive performance under normobaric hypoxia, hypobaric hypoxia, and control conditions (mean over time)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.
Outcome measures
| Measure |
Simulated Altitude
n=20 Participants
The participants are exposed to simulated altitude in a normobaric situation.
Cloud 9: 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.
|
Terrestrial Altitude
n=20 Participants
The participants are exposed to terrestrial altitude in a hypobaric situation.
Terrestrial altitude: 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.
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Control
n=20 Participants
the participants are exposed to a normoxic and normobaric environment.
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Control
the participants are exposed to a normoxic and normobaric environment.
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|---|---|---|---|---|
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Oxygenation of the Brain
rest
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54.6 percentage of oxygen saturation
Standard Deviation 4.6
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54.3 percentage of oxygen saturation
Standard Deviation 4.9
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59.4 percentage of oxygen saturation
Standard Deviation 3.8
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—
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Oxygenation of the Brain
during congnitive performance test
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55.4 percentage of oxygen saturation
Standard Deviation 4.5
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55.6 percentage of oxygen saturation
Standard Deviation 5.1
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60.7 percentage of oxygen saturation
Standard Deviation 3.8
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—
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PRIMARY outcome
Timeframe: 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)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.
Outcome measures
| Measure |
Simulated Altitude
n=20 Participants
The participants are exposed to simulated altitude in a normobaric situation.
Cloud 9: 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.
|
Terrestrial Altitude
n=20 Participants
The participants are exposed to terrestrial altitude in a hypobaric situation.
Terrestrial altitude: 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.
|
Control
n=20 Participants
the participants are exposed to a normoxic and normobaric environment.
|
Control
n=20 Participants
the participants are exposed to a normoxic and normobaric environment.
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|---|---|---|---|---|
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Oxygenation of the Blood
Rest
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91.3 % SpO2
Standard Deviation 1.7
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89.5 % SpO2
Standard Deviation 1.8
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90.7 % SpO2
Standard Deviation 1.8
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95.8 % SpO2
Standard Deviation 1.2
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Oxygenation of the Blood
after 3-min step-test
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80.5 % SpO2
Standard Deviation 80.5
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78.7 % SpO2
Standard Deviation 3.1
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80.5 % SpO2
Standard Deviation 3.0
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90.7 % SpO2
Standard Deviation 2.8
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PRIMARY outcome
Timeframe: 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)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.
Outcome measures
| Measure |
Simulated Altitude
n=20 Participants
The participants are exposed to simulated altitude in a normobaric situation.
Cloud 9: 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.
|
Terrestrial Altitude
n=20 Participants
The participants are exposed to terrestrial altitude in a hypobaric situation.
Terrestrial altitude: 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.
|
Control
n=20 Participants
the participants are exposed to a normoxic and normobaric environment.
|
Control
n=20 Participants
the participants are exposed to a normoxic and normobaric environment.
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|---|---|---|---|---|
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Mean Arterial Pressure
Rest
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93.6 mmHg
Standard Deviation 8.3
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97.4 mmHg
Standard Deviation 8.8
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98.1 mmHg
Standard Deviation 7.7
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94.0 mmHg
Standard Deviation 8.1
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Mean Arterial Pressure
3-min step-test
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114.7 mmHg
Standard Deviation 11.8
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110.6 mmHg
Standard Deviation 28.0
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122.1 mmHg
Standard Deviation 10.5
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116.8 mmHg
Standard Deviation 12.7
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PRIMARY outcome
Timeframe: at baseline and the end of the submaximal step test (point measurements)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.
Outcome measures
| Measure |
Simulated Altitude
n=20 Participants
The participants are exposed to simulated altitude in a normobaric situation.
Cloud 9: 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.
|
Terrestrial Altitude
n=20 Participants
The participants are exposed to terrestrial altitude in a hypobaric situation.
Terrestrial altitude: 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.
|
Control
n=20 Participants
the participants are exposed to a normoxic and normobaric environment.
|
Control
n=20 Participants
the participants are exposed to a normoxic and normobaric environment.
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|---|---|---|---|---|
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Heart Rate
Rest
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77.6 beats per minute
Standard Deviation 10.2
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75.0 beats per minute
Standard Deviation 9.6
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86.0 beats per minute
Standard Deviation 11.2
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71.0 beats per minute
Standard Deviation 10.9
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Heart Rate
3-min step-test
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141.6 beats per minute
Standard Deviation 10.4
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141.9 beats per minute
Standard Deviation 10.6
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144.9 beats per minute
Standard Deviation 5.8
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137.4 beats per minute
Standard Deviation 12.9
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PRIMARY outcome
Timeframe: at the end of 15min baseline period and the end of the step-up test (point measurements)Lactate measurements are performed by capillary blood measurement. This measurement is taken during the baseline measurements and after the step-up task.
Outcome measures
| Measure |
Simulated Altitude
n=20 Participants
The participants are exposed to simulated altitude in a normobaric situation.
Cloud 9: 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.
|
Terrestrial Altitude
n=20 Participants
The participants are exposed to terrestrial altitude in a hypobaric situation.
Terrestrial altitude: 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.
|
Control
n=20 Participants
the participants are exposed to a normoxic and normobaric environment.
|
Control
n=20 Participants
the participants are exposed to a normoxic and normobaric environment.
|
|---|---|---|---|---|
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Concentration of Blood Lactate
rest
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2.0 mmol/l
Standard Deviation 0.9
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2.4 mmol/l
Standard Deviation 0.8
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2.3 mmol/l
Standard Deviation 0.8
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1.7 mmol/l
Standard Deviation 0.6
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Concentration of Blood Lactate
3-min step-test
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5.0 mmol/l
Standard Deviation 1.4
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4.9 mmol/l
Standard Deviation 1.5
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4.8 mmol/l
Standard Deviation 1.6
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4.7 mmol/l
Standard Deviation 2.4
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PRIMARY outcome
Timeframe: Before the cognitive performance test (point measurement)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.
Outcome measures
| Measure |
Simulated Altitude
n=20 Participants
The participants are exposed to simulated altitude in a normobaric situation.
Cloud 9: 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.
|
Terrestrial Altitude
n=20 Participants
The participants are exposed to terrestrial altitude in a hypobaric situation.
Terrestrial altitude: 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.
|
Control
n=20 Participants
the participants are exposed to a normoxic and normobaric environment.
|
Control
n=20 Participants
the participants are exposed to a normoxic and normobaric environment.
|
|---|---|---|---|---|
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Sleep Quality
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5.6 score on a scale
Standard Deviation 1.3
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7.0 score on a scale
Standard Deviation 1.8
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5.5 score on a scale
Standard Deviation 1.9
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5.8 score on a scale
Standard Deviation 1.6
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PRIMARY outcome
Timeframe: After performing the 3-min step-test (point measurment)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.
Outcome measures
| Measure |
Simulated Altitude
n=20 Participants
The participants are exposed to simulated altitude in a normobaric situation.
Cloud 9: 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.
|
Terrestrial Altitude
n=20 Participants
The participants are exposed to terrestrial altitude in a hypobaric situation.
Terrestrial altitude: 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.
|
Control
n=20 Participants
the participants are exposed to a normoxic and normobaric environment.
|
Control
n=20 Participants
the participants are exposed to a normoxic and normobaric environment.
|
|---|---|---|---|---|
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Altitude Sickness
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0.6 score on a scale
Standard Deviation 0.7
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1.4 score on a scale
Standard Deviation 1.3
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0.4 score on a scale
Standard Deviation 0.5
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0.6 score on a scale
Standard Deviation 0.9
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PRIMARY outcome
Timeframe: After each experimental day, in the evening between 8:30 PM and midnight, measured once before participants went to bed (point measurment)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.
Outcome measures
| Measure |
Simulated Altitude
n=10 Participants
The participants are exposed to simulated altitude in a normobaric situation.
Cloud 9: 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.
|
Terrestrial Altitude
n=10 Participants
The participants are exposed to terrestrial altitude in a hypobaric situation.
Terrestrial altitude: 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.
|
Control
n=10 Participants
the participants are exposed to a normoxic and normobaric environment.
|
Control
n=10 Participants
the participants are exposed to a normoxic and normobaric environment.
|
|---|---|---|---|---|
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Concentration of Salivary Cortisol
|
0.24 μg/l
Standard Deviation 0.16
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0.31 μg/l
Standard Deviation 0.19
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0.25 μg/l
Standard Deviation 0.12
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0.23 μg/l
Standard Deviation 0.19
|
Adverse Events
Simulated Altitude
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Terrestrial Altitude
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Control
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Dr Erich Hohenauer
Rehabilitation and Exercise Science Laboratory (RES lab), University of Applied Sciences and Arts of Southern Switzerland (SUPSI)
Phone: 0041 81 300 01 75
Email: [email protected]
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place