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High Altitude and Exogenous Carbohydrate Oxidation

Primary Purpose

Glucose Metabolism, High Altitude

Status
Completed
Phase
Not Applicable
Locations
United States
Study Type
Interventional
Intervention
Sea Level
High Altitude
Sponsored by
United States Army Research Institute of Environmental Medicine
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional basic science trial for Glucose Metabolism

Eligibility Criteria

18 Years - 39 Years (Adult)MaleAccepts Healthy Volunteers

Inclusion Criteria:

  • Men aged 18 - 39 years
  • Born at altitudes less than 2,100 m (~7,000 feet; Examples include Santa Fe, New Mexico; Laramie, Wyoming; Etc.)
  • Physically active based on assessment of physical activity history (2-4 days per week aerobic and/or resistance exercise)
  • Have supervisor approval (permanent party military and civilians)
  • Willing to refrain from alcohol, smokeless nicotine products and dietary supplement use during study periods
  • Refrain from taking any nonsteroidal anti-inflammatory drugs (NSAIDs; e.g. aspirin, Advil®, Aleve®, Naprosyn®, or any aspirin-containing product) for 10 days before and at least 5 days AFTER each muscle biopsy. (*Tylenol® or acetaminophen is ok to use if needed for discomfort)

Exclusion Criteria:

  • Born at altitudes greater than 2,100 m (~7,000 feet; Examples include Santa Fe, New Mexico; Laramie, Wyoming; Etc.)
  • 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 2 months (Examples include Ft. Huachuca, Arizona; Lima, Peru; Feldberg, Germany, Etc.)
  • Musculoskeletal injuries that compromise exercise capability
  • Metabolic or cardiovascular abnormalities (determined by resting ECG), gastrointestinal disorders (e.g., kidney disease, diabetes, cardiovascular disease, etc.)
  • Medication that affects macronutrient metabolism (i.e., diabetes medications, statins, corticosteroids, etc) and/or the ability to participate in strenuous exercise
  • Evidence of apnea or other sleeping disorders
  • Prior diagnosis of high altitude pulmonary edema (HAPE) or high altitude cerebral edema (HACE)
  • Presence of asthma or respiratory tract infections (< 1 month prior)
  • Allergies or intolerance to foods (including but not limited to lactose intolerance/milk allergy), vegetarian practices, or medications (including, but not limited to, lidocaine ) to be utilized in the study
  • Smoking or vaping
  • History of complications with lidocaine
  • Taking medications that interfere with oxygen delivery and transport (Includes sedatives, sleeping aids, tranquilizers and/or any medication that depresses ventilation, diuretics, alpha and beta blockers)
  • Evidence of any physical, mental, and/or medical conditions that would make the proposed studies relatively more hazardous as determined by the Office of Medical Support and Oversight
  • Present condition of alcoholism, anabolic steroids, or other substance abuse issues
  • Anemia (hematocrit <38% and hemoglobin <12.5 g/dL) and Sickle Cell Anemia/Trait
  • Abnormal prothrombin time (PT)/ partial thromboplastin time (PTT) test or problems with blood clotting
  • Blood donation within 8 weeks of beginning the study

Sites / Locations

  • USARIEM

Arms of the Study

Arm 1

Arm 2

Arm Type

Active Comparator

Experimental

Arm Label

Sea Level

High Altitude

Arm Description

Carbohydrate metabolism measured at SL

Carbohydrate metabolism measured at HA

Outcomes

Primary Outcome Measures

Rate of Exogenous Carbohydrate Oxidation
Use indirect calorimetry and stable isotope methodologies to measure if acute HA exposure changes the rate of exogenous carbohydrate oxidation during steady-state aerobic exercise compared to SL
Rate of Glucose Turnover
Use stable isotope methodologies to measure if acute HA exposure changes the rate of glucose turnover during steady-state aerobic exercise compared to SL

Secondary Outcome Measures

Full Information

First Posted
August 30, 2018
Last Updated
August 6, 2021
Sponsor
United States Army Research Institute of Environmental Medicine
Collaborators
University of Arkansas
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1. Study Identification

Unique Protocol Identification Number
NCT03851744
Brief Title
High Altitude and Exogenous Carbohydrate Oxidation
Official Title
The Mechanistic Effects of Acute Hypobaric Hypoxia on Exogenous Carbohydrate Utilization During Steady-state Aerobic Exercise
Study Type
Interventional

2. Study Status

Record Verification Date
August 2021
Overall Recruitment Status
Completed
Study Start Date
November 28, 2018 (Actual)
Primary Completion Date
November 1, 2019 (Actual)
Study Completion Date
September 1, 2020 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Sponsor
Name of the Sponsor
United States Army Research Institute of Environmental Medicine
Collaborators
University of Arkansas

4. Oversight

Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Data Monitoring Committee
No

5. Study Description

Brief Summary
Recent studies have reported that oxidation of exogenous carbohydrate is reduced under acute hypobaric hypoxic (high altitude; HA) conditions compared to normoxia (sea level; SL) in native lowlanders. However, the mechanisms by which HA suppresses exogenous carbohydrate oxidation are not known. This study will seek to confirm that acute HA exposure decreases exogenous carbohydrate oxidation during steady-state aerobic exercise compared to SL, and explore if the mechanism inhibiting plasma glucose uptake is insulin dependent or independent.
Detailed Description
This randomized crossover study will examine substrate metabolic responses to ingesting supplemental carbohydrate during steady-state aerobic-type exercise at sea level (SL) and following acute (~5 h) exposure to HA (4,300 m) conditions in 10 healthy, recreationally active adults between the ages of 18-39 yrs. Following a 48-hr muscle glycogen normalization period, volunteers will complete 80-min of metabolically-matched, steady-state aerobic exercise on a treadmill, and consume 145 g of glucose (1.8 g·min-1) at SL and HA. Treadmill exercise will be performed at the same absolute workload, with speed and grade being the same at SL and HA to induce the same absolute workload between phases. SL and HA trials will occur in the US Army Research Institute of Environmental Medicine (USARIEM) hypobaric chamber and will be separated by a minimum 7-d washout period between each protocol day. 6-6-[2H2] glucose will be used as a tracer to assess glucose turnover. Indirect calorimetry, breath sampling for 13C/12C expired in CO2, and urine collections will be used to determine carbohydrate, fat, and protein oxidation during exercise at SL and HA. Serial blood draws will be collected during each trial to assess endocrine and circulating substrate responses to exercise, carbohydrate, and hypoxia. Muscle biopsies will be collected before and after steady-state exercise to examine intramuscular glucose transport expression and translocation, glycogen status, and activity enzyme intermediates in aerobic and anaerobic energy metabolism.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Glucose Metabolism, High Altitude

7. Study Design

Primary Purpose
Basic Science
Study Phase
Not Applicable
Interventional Study Model
Crossover Assignment
Masking
None (Open Label)
Allocation
Randomized
Enrollment
10 (Actual)

8. Arms, Groups, and Interventions

Arm Title
Sea Level
Arm Type
Active Comparator
Arm Description
Carbohydrate metabolism measured at SL
Arm Title
High Altitude
Arm Type
Experimental
Arm Description
Carbohydrate metabolism measured at HA
Intervention Type
Other
Intervention Name(s)
Sea Level
Intervention Description
Carbohydrate consumed at 1.8 g/min during treadmill exercise at SL
Intervention Type
Other
Intervention Name(s)
High Altitude
Intervention Description
Carbohydrate consumed at 1.8 g/min during treadmill exercise at HA
Primary Outcome Measure Information:
Title
Rate of Exogenous Carbohydrate Oxidation
Description
Use indirect calorimetry and stable isotope methodologies to measure if acute HA exposure changes the rate of exogenous carbohydrate oxidation during steady-state aerobic exercise compared to SL
Time Frame
7 hours
Title
Rate of Glucose Turnover
Description
Use stable isotope methodologies to measure if acute HA exposure changes the rate of glucose turnover during steady-state aerobic exercise compared to SL
Time Frame
7 hours

10. Eligibility

Sex
Male
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
39 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria: Men aged 18 - 39 years Born at altitudes less than 2,100 m (~7,000 feet; Examples include Santa Fe, New Mexico; Laramie, Wyoming; Etc.) Physically active based on assessment of physical activity history (2-4 days per week aerobic and/or resistance exercise) Have supervisor approval (permanent party military and civilians) Willing to refrain from alcohol, smokeless nicotine products and dietary supplement use during study periods Refrain from taking any nonsteroidal anti-inflammatory drugs (NSAIDs; e.g. aspirin, Advil®, Aleve®, Naprosyn®, or any aspirin-containing product) for 10 days before and at least 5 days AFTER each muscle biopsy. (*Tylenol® or acetaminophen is ok to use if needed for discomfort) Exclusion Criteria: Born at altitudes greater than 2,100 m (~7,000 feet; Examples include Santa Fe, New Mexico; Laramie, Wyoming; Etc.) 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 2 months (Examples include Ft. Huachuca, Arizona; Lima, Peru; Feldberg, Germany, Etc.) Musculoskeletal injuries that compromise exercise capability Metabolic or cardiovascular abnormalities (determined by resting ECG), gastrointestinal disorders (e.g., kidney disease, diabetes, cardiovascular disease, etc.) Medication that affects macronutrient metabolism (i.e., diabetes medications, statins, corticosteroids, etc) and/or the ability to participate in strenuous exercise Evidence of apnea or other sleeping disorders Prior diagnosis of high altitude pulmonary edema (HAPE) or high altitude cerebral edema (HACE) Presence of asthma or respiratory tract infections (< 1 month prior) Allergies or intolerance to foods (including but not limited to lactose intolerance/milk allergy), vegetarian practices, or medications (including, but not limited to, lidocaine ) to be utilized in the study Smoking or vaping History of complications with lidocaine Taking medications that interfere with oxygen delivery and transport (Includes sedatives, sleeping aids, tranquilizers and/or any medication that depresses ventilation, diuretics, alpha and beta blockers) Evidence of any physical, mental, and/or medical conditions that would make the proposed studies relatively more hazardous as determined by the Office of Medical Support and Oversight Present condition of alcoholism, anabolic steroids, or other substance abuse issues Anemia (hematocrit <38% and hemoglobin <12.5 g/dL) and Sickle Cell Anemia/Trait Abnormal prothrombin time (PT)/ partial thromboplastin time (PTT) test or problems with blood clotting Blood donation within 8 weeks of beginning the study
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Lee M Margolis, PhD
Organizational Affiliation
Military Nutrition Division, USARIEM
Official's Role
Principal Investigator
Facility Information:
Facility Name
USARIEM
City
Natick
State/Province
Massachusetts
ZIP/Postal Code
01760
Country
United States

12. IPD Sharing Statement

Plan to Share IPD
No

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High Altitude and Exogenous Carbohydrate Oxidation

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