Hypoxia, Appetite, and Energy Intake in Young Female Adults

Appetite and Energy Intake in Young Female Adults During and After Simulated High-Altitude

The goal of this clinical trial is to investigate the effects of acute passive continuous hypoxemia (simulated high-altitude at rest) on appetite and energy intake in healthy young female adults. The main questions it aims to answer are:

• Does six hours of simulated high-altitude (5000 meters) reduce scores of subjective appetite and energy intake?
• Do changes in appetite and energy intake persist in the hours following the end of hypoxic exposure? Researchers will compare the effects of simulated high-altitude to a control normoxia (sea-level) condition to see if exposure to low oxygen levels independently affect appetite and energy intake.

Participants will:

• Visit the laboratory for a preliminary screening session to assess eligibility.
• Undergo two randomized, single-blind, experimental sessions consisting of six hours of passive exposure to normoxia or hypoxia in a climate-controlled chamber.
• Consume foods provided from a curated list, served in ad libitum quantities, after leaving the laboratory to assess post-exposure energy intake.

Study Overview

• Status: Recruiting
• Conditions: Hypoxia; Energy Intake; Appetite; Altitude
• Intervention / Treatment: Other: Normoxia; Other: Hypoxia (simulated altitude of 5000 meters above sea-level)

• Study Type: Interventional
• Enrollment (Estimated): 10
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Pascal Imbeault, PhD; Phone Number: 7290 6135625800; Email: imbeault@uottawa.ca

Study Locations

• Canada
  • Ontario
    • Ottawa, Ontario, Canada, K1N 6N5
      • Recruiting
      • Behavioural and Metabolic Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa
      • Contact: Pascal Imbeault, PhD; Phone Number: 7290 6135625800; Email: imbeault@uottawa.ca

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• English or French speaking
• Ability to provide informed consent

Exclusion Criteria:

• History or evidence of chronic disease
• Current use of hypolipemic medication
• Current use of hormonal contraceptives
• Current use of antidepressants
• Current use of anticoagulants
• Ongoing smoking status
• Experiencing pregnancy, puerperium, or irregular menstrual cycles

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
Experimental: Normoxia	Other: Normoxia; Participants will undergo a 6-hour passive exposure to normoxia in a climate-controlled environmental chamber maintained at 22°C with 30% relative humidity. They will remain in a fasted state throughout the exposure period.
Experimental: Hypoxia (simulated altitude of 5000 meters above sea-level)	Other: Hypoxia (simulated altitude of 5000 meters above sea-level); Participants will undergo a 6-hour passive exposure to a simulated altitude of 5000 meters above sea-level in a climate-controlled environmental chamber maintained at 22°C with 30% relative humidity. They will remain in a fasted state throughout the exposure period.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline in desire to eat	Scores of subjective desire to eat, measured using visual analog scales. Measurements are performed upon arrival at the laboratory (baseline), hourly during the exposure, immediately after a 30-minute ad libitum buffet, immediately before bedtime, and 24 hours after the baseline measurement.	Baseline and 6 hours; Baseline and 24 hours
Change from baseline in hunger	Scores of subjective hunger, measured using visual analog scales. Measurements are performed upon arrival at the laboratory (baseline), hourly during the exposure, immediately after a 30-minute ad libitum buffet, immediately before bedtime, and 24 hours after the baseline measurement.	Baseline and 6 hours; Baseline and 24 hours
Change from baseline in fullness	Scores of subjective fullness, measured using visual analog scales. Measurements are performed upon arrival at the laboratory (baseline), hourly during the exposure, immediately after a 30-minute ad libitum buffet, immediately before bedtime, and 24 hours after the baseline measurement.	Baseline and 6 hours; Baseline and 24 hours
Change from baseline in prospective food consumption	Scores of subjective prospective food consumption, measured using visual analog scales. Measurements are performed upon arrival at the laboratory (baseline), hourly during the exposure, immediately after a 30-minute ad libitum buffet, immediately before bedtime, and 24 hours after the baseline measurement.	Baseline and 6 hours; Baseline and 24 hours
Energy intake immediately after 6 hours of exposure (buffet)	Energy intake in the laboratory during a 30-minute ad libitum buffet immediately after 6 hours of exposure, administered using a validated food menu (McNeil, 2012) and analyzed using the Food Processor SQL from ESHA Research, Inc.	Hour 6 of exposure
Energy intake post-buffet	Energy intake outside the laboratory between end-buffet and bedtime, administered using a validated food menu (McNeil, 2012) and analyzed using the Food Processor SQL from ESHA Research, Inc.	6.5 hours of exposure and 24 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Heart rate	Measured continuously throughout the exposure.	6 hours
Oxyhemoglobin saturation	Measured continuously throughout the exposure.	6 hours
Systolic blood pressure	Measured upon arrival at the laboratory (baseline), hourly during the exposure, and immediately after eating.	6 hours
Diastolic blood pressure	Measured upon arrival at the laboratory (baseline), hourly during the exposure, and immediately after eating.	6 hours
Lake Louise Acute Mountain Sickness Score	Peak score on the Lake Louise Acute Mountain Sickness questionnaire, measured upon arrival at the laboratory (baseline), hourly during the exposure, and immediately after eating.	6 hours
Fluid consumption during exposure	Average hourly fluid consumption calculated by weighing participant water intake at the start and end of each hour of exposure (normalized to the exposure duration).	6 hours
Fluid loss during exposure	Fluid loss calculated as the change in body mass during each exposure presented as a percentage of baseline body mass (corrected for fluid consumption)	6 hours
Change from baseline in explicit liking using the LFPQ	Explicit liking will be measured using the Leeds Food Preference Questionnaire. Measurements will be taken upon arrival at the laboratory (baseline), following 5 hours of exposure, and after a 30-min ad libitum buffet.	Baseline and 6.5 hours of exposure
Change from baseline in explicit wanting using the LFPQ	Explicit wanting will be measured using the Leeds Food Preference Questionnaire. Measurements will be taken upon arrival at the laboratory (baseline), following 5 hours of exposure, and after a 30-min ad libitum buffet.	Baseline and 6.5 hours of exposure
Change from baseline in implicit wanting using the LFPQ	Implicit wanting will be measured using the Leeds Food Preference Questionnaire. Measurements will be taken upon arrival at the laboratory (baseline), following 5 hours of exposure, and after a 30-min ad libitum buffet.	Baseline and 6.5 hours of exposure
Change from baseline in olfaction	Olfaction will be measured using the Sniffin' Sticks (Burghart Instruments, Wedel, Germany), a 3-test battery of odorized markers that measure odor detection threshold, odor discrimination, and odor identification. Measurements will be performed upon arrival at the laboratory (baseline) and following 4 hours of exposure.	Baseline and Hour 4 of exposure
Change from baseline in gustation	Olfaction will be measured using Taste Strips (Burghart Instruments, Wedel, Germany). Measurements will be performed upon arrival at the laboratory (baseline) and following 4 hours of exposure.	Baseline and Hour 4 of exposure
Change from baseline in resting energy expenditure	Resting energy expenditure will be measured via indirect calorimetry upon arrival at the laboratory (baseline) and following 5 hours of exposure.	Baseline and Hour 5 of exposure
Change from baseline in respiratory exchange ratio	Respiratory exchange ratio will be measured via indirect calorimetry upon arrival at the laboratory (baseline) and following 5 hours of exposure.	Baseline and Hour 5 of exposure
Change from baseline in plasma glucose concentrations	Plasma glucose concentrations will be measured via colorimetric assays from venous blood samples collected upon arrival at the laboratory (baseline) and hourly during the exposure (i.e., 0 or baseline, 60, 120, 180, 240, 300, and 360 minutes).	6 hours
Change from baseline in plasma insulin concentrations	Plasma insulin concentrations will be measured via colorimetric assays from venous blood samples collected upon arrival at the laboratory (baseline) and hourly during the exposure (i.e., 0 or baseline, 60, 120, 180, 240, 300, and 360 minutes).	6 hours
Change from baseline in plasma non-esterified fatty acid concentrations	Plasma non-esterified fatty acid concentrations will be measured via colorimetric assays from venous blood samples collected upon arrival at the laboratory (baseline) and hourly during the exposure (i.e., 0 or baseline, 60, 120, 180, 240, 300, and 360 minutes).	6 hours
Change from baseline in plasma triglyceride concentrations	Plasma triglyceride concentrations will be measured via colorimetric assays from venous blood samples collected upon arrival at the laboratory (baseline) and hourly during the exposure (i.e., 0 or baseline, 60, 120, 180, 240, 300, and 360 minutes).	6 hours
Change from baseline in plasma beta-hydroxybutyrate concentrations	Plasma beta-hydroxybutyrate concentrations will be measured via colorimetric assays from venous blood samples collected upon arrival at the laboratory (baseline) and hourly during the exposure (i.e., 0 or baseline, 60, 120, 180, 240, 300, and 360 minutes).	6 hours

Collaborators and Investigators

• Sponsor: University of Ottawa
• Collaborators: Hopital Montfort; Natural Sciences and Engineering Research Council, Canada; Institut du Savoir Montfort

Study record dates

Study Major Dates

• Study Start (Actual): November 13, 2024
• Primary Completion (Estimated): December 1, 2025
• Study Completion (Estimated): December 1, 2025

Study Registration Dates

• First Submitted: March 17, 2025
• First Submitted That Met QC Criteria: March 28, 2025
• First Posted (Actual): April 4, 2025

Study Record Updates

• Last Update Posted (Actual): April 4, 2025
• Last Update Submitted That Met QC Criteria: March 28, 2025
• Last Verified: October 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Signs and Symptoms, Respiratory; Hypoxia
• Other Study ID Numbers: H-06-18-837

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No