Effects of Overnight Low Oxygen Exposure on Energy Balance

November 26, 2021 updated by: Claire E. Berryman, Florida State University

Effects of an Overnight, 8-hour Low Oxygen Exposure on Resting Energy Expenditure and Appetite: a Pilot Study

This research study will evaluate changes in resting metabolic rate, appetite, and heart rate variability following overnight exposure (8 h/night) to normobaric hypoxia (NH) or normobaric normoxic (NN). In randomized order, participants will sleep one night in NH conditions (~15% oxygen; achieved with nitrogen dilution, equivalent to ~8500 feet elevation) and another night in NN (control) conditions (~20% oxygen; achieved with nitrogen dilution, equivalent to ~1000 feet elevation).

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Weight loss is a common factor reported in lowlanders traveling to high altitudes. Although the exact cause is unknown, studies have shown that weight loss at high altitude is associated with the amount of time and severity of the altitude exposure. Upon arrival to high altitude (≥ 5000 feet), numerous physiological adaptations occur that may promote weight loss, such as increased energy expenditure and reduced appetite. The breadth of current altitude research is limited by the logistical and monetary constraints of traveling to remote locations or access to an altitude chamber. A more logistically feasible alternative is the simulation of low oxygen conditions at sea level, using a commercially available tent and generator system to reduce ambient oxygen concentrations. The current research study will evaluate changes in resting metabolic rate, appetite, and heart rate variability following overnight exposure (8 h/night) to normobaric hypoxia (NH) or normobaric normoxic (NN). In randomized order, participants will sleep one night in NH conditions (~15% oxygen; achieved with nitrogen dilution, equivalent to ~8500 feet elevation) and another night in NN (control) conditions (~20% oxygen; achieved with nitrogen dilution, equivalent to ~1000 feet elevation). In the morning, following NH or NN exposure, resting metabolic rate will be measured using indirect calorimetry, appetite using an ad libitum buffet meal protocol, and heart rate variability by electrocardiogram. It is hypothesized that exposure to overnight NH will result in increased resting metabolic rate, decreased appetite, and decreased heart rate variability.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
20

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Florida
      • Tallahassee, Florida, United States, 32306
        • Florida State University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

20 years to 45 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Men and women aged 20 - 45 years
  • Body mass index between 18.5 - 24.5 kg/m2
  • Born at altitudes less than 2,100 meters (~7,000 feet)
  • Currently residing in Tallahassee, Florida or the surrounding area
  • Not taking any medication(s) that interfere with metabolism or oxygen delivery/transport for four weeks before and throughout the entire study (e.g., includes sedatives, sleeping aids, tranquilizers, and/or any medication that depresses ventilation, diuretics, alpha, and beta-blockers).
  • Willing to refrain from smoking, vaping, chewing tobacco, and dietary supplement use throughout the entire study
  • Willing to spend two overnight visits on the Florida State University campus.

Exclusion Criteria:

  • Living in areas that are more than 1,200 m (~4,000 feet), or have traveled to areas that are more than 1,200 m for five days or more within the last two months
  • Metabolic or cardiovascular abnormalities, gastrointestinal disorders, or any condition that interferes with metabolism or oxygen delivery/transport (e.g., kidney disease, diabetes, cardiovascular disease, etc.)
  • Prior diagnosis of apnea or other sleeping disorders
  • Prior diagnosis of high-altitude pulmonary edema or high-altitude cerebral edema
  • Prior diagnosis of anemia or sickle cell anemia/trait
  • Present condition of alcoholism, anabolic steroid, or other substance abuse issues
  • Women who are pregnant, lactating, planning to become pregnant, or who have had an irregular menstrual cycle in the past six months.
  • Allergies or intolerance to foods included in the standardized or ad libitum meal (e.g., lactose intolerance/milk allergy)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Normobaric Hypoxia (NH)
Overnight exposure (8 hours) to NH conditions (~15% oxygen; achieved with nitrogen dilution, equivalent to ~8500 feet elevation) using a commercially available tent and generator system (Hypoxico, Inc., New York, NY).
Device: Normobaric Hypoxia
Low oxygen exposure to mimic ~8500 feet elevation.
Device: Normobaric Normoxia
Normal oxygen exposure to mimic ~1000 feet elevation (sham comparator).
Sham Comparator: Normobaric Normoxia (NN)
Overnight exposure (8 hours) to NN conditions (~20% oxygen; achieved with nitrogen dilution, equivalent to ~1000 feet elevation) using a commercially available tent and generator system (Hypoxico, Inc., New York, NY).
Device: Normobaric Hypoxia
Low oxygen exposure to mimic ~8500 feet elevation.
Device: Normobaric Normoxia
Normal oxygen exposure to mimic ~1000 feet elevation (sham comparator).

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Resting metabolic rate (kcal/d) following exposure to NH or NN conditions
Time Frame: 8 hours
Resting metabolic rate will be accessed using indirect calorimetry (TrueOne 2400, Parvo Medics, Salt Lake City, UT) following 8 hours of overnight exposure to NH or NN.
8 hours

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Objective appetite following exposure to NH or NN conditions
Time Frame: 8 hours
Objective appetite will be assessed by measuring total energy intake during an ad libitum buffet-style meal provided to participants following 8 hours of overnight exposure to NH or NN.
8 hours
Food preferences following exposure to NH or NN conditions
Time Frame: 8 hours
Food preferences will be assessed by measuring macronutrient intake during an ad libitum buffet-style meal provided to participants following 8 hours of overnight exposure to NH or NN.
8 hours
Fasting and postprandial hunger following exposure to NH or NN conditions
Time Frame: Hunger will be measured pre-meal (0 min), immediately post-meal, and at 15, 30, 45, 60, 90, and 120 min following 8 hours of NH or NN exposure
Measures will be assessed before and after the ad-libitum buffet meal using visual analog scales following 8 hours of overnight exposure to NH or NN.
Hunger will be measured pre-meal (0 min), immediately post-meal, and at 15, 30, 45, 60, 90, and 120 min following 8 hours of NH or NN exposure
Fasting and postprandial satiety following exposure to NH or NN conditions
Time Frame: Satiety will be measured pre-meal (0 min), immediately post-meal, and at 15, 30, 45, 60, 90, and 120 min following 8 hours of NH or NN exposure
Measures will be assessed before and after the ad-libitum buffet meal using visual analog scales following 8 hours of overnight exposure to NH or NN.
Satiety will be measured pre-meal (0 min), immediately post-meal, and at 15, 30, 45, 60, 90, and 120 min following 8 hours of NH or NN exposure
Fasting and postprandial prospective food consumption following exposure to NH or NN conditions
Time Frame: Prospective food consumption will be measured pre-meal (0 min), immediately post-meal, and at 15, 30, 45, 60, 90, and 120 min following 8 hours of NH or NN exposure
Measures will be assessed before and after the ad-libitum buffet meal using visual analog scales following 8 hours of overnight exposure to NH or NN.
Prospective food consumption will be measured pre-meal (0 min), immediately post-meal, and at 15, 30, 45, 60, 90, and 120 min following 8 hours of NH or NN exposure
Fasting and postprandial subjective appetite following exposure to NH or NN conditions
Time Frame: Subjective appetite will be measured pre-meal (0 min), immediately post-meal, and at 15, 30, 45, 60, 90, and 120 min following 8 hours of NH or NN exposure
Measures will be assessed before and after the ad-libitum buffet meal using visual analog scales following 8 hours of overnight exposure to NH or NN.
Subjective appetite will be measured pre-meal (0 min), immediately post-meal, and at 15, 30, 45, 60, 90, and 120 min following 8 hours of NH or NN exposure
Energy intake following exposure to NH or NN conditions
Time Frame: 8 hours
Energy intake will be accessed using the Automated Self-Administered 24-Hour (ASA24®) Dietary Assessment Tool to complete dietary records for 2 days following 8 hours of overnight exposure to NH or NN.
8 hours
Macronutrient intake following exposure to NH or NN conditions
Time Frame: 8 hours
Macronutrient intake will be accessed using the Automated Self-Administered 24-Hour (ASA24®) Dietary Assessment Tool to complete dietary records for 2 days following 8 hours of overnight exposure to NH or NN.
8 hours
Heart rate variability following exposure to NH or NN conditions
Time Frame: 8 hours
Heart rate variability will be measured using a 3-lead electrocardiogram following 8 hours of overnight exposure to NH or NN.
8 hours
Prevalence of acute mountain sickness following exposure to NH or NN conditions
Time Frame: 8 hours
Prevalence of acute mountain sickness will be accessed using the Environmental Symptoms Questionnaire following 8 hours of overnight exposure to NH or NN.
8 hours
Severity of acute mountain sickness following exposure to NH or NN conditions
Time Frame: 8 hours
Severity of acute mountain sickness will be accessed using the Environmental Symptoms Questionnaire following 8 hours of overnight exposure to NH or NN.
8 hours
Continuous oxygen saturation during exposure to NH or NN
Time Frame: 8 hours
Oxygen saturation will be measured continuously using a finger pulse oximeter (PalmSAT® 2500, Nonin Medical, Inc., Plymouth, MN) during 8 hours of overnight exposure to NH or NN.
8 hours
Sleep quality following exposure to NH or NN conditions
Time Frame: 8 hours
Sleep quality will be measured by the Pittsburgh Sleep Quality Index following 8 hours of overnight exposure to NH or NN.
8 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Florida State University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Claire E Berryman, Ph.D., Department of Nutrition, Food, and Exercise Science at Florida State University.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
December 11, 2019

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
October 2, 2021

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
October 2, 2021

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 26, 2019

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 2, 2019

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 5, 2019

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 29, 2021

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 26, 2021

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2021

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • STUDY00000184

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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