High Altitude and Exogenous Carbohydrate Oxidation

NCT03851744 | Completed Results

• 1 other identifier: 18-09HC
• Study Type: interventional
• Target: 10
• Locations: 1 country
• Sites: 1

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.

Conditions

Glucose Metabolism; High Altitude

Outcome Measures

Primary Outcomes (2)

• 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

  7 hours

• 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

  7 hours

Study Arms (2)

Sea Level

ACTIVE COMPARATOR

Carbohydrate metabolism measured at SL

Other: Sea Level

High Altitude

EXPERIMENTAL

Carbohydrate metabolism measured at HA

Other: High Altitude

Interventions

Sea Level OTHER

Carbohydrate consumed at 1.8 g/min during treadmill exercise at SL

Sea Level

High Altitude OTHER

Carbohydrate consumed at 1.8 g/min during treadmill exercise at HA

High Altitude

Eligibility Criteria

• Age: 18 Years - 39 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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)

You may not qualify if:

• 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

Sponsors & Collaborators

• United States Army Research Institute of Environmental Medicine: lead
• University of Arkansas: collaborator

Study Sites (1)

USARIEM

Natick, Massachusetts, 01760, United States

Location

MeSH Terms

Conditions

Altitude Sickness

Interventions

Sea Level Rise

Condition Hierarchy (Ancestors)

Respiration Disorders; Respiratory Tract Diseases

Intervention Hierarchy (Ancestors)

Oceans and Seas; Geological Phenomena; Physical Phenomena; Climate Change; Climatic Processes; Ecological and Environmental Phenomena; Biological Phenomena; Water Movements

Results Point of Contact

• Title: Dr. Lee Margolis
• Organization: USARIEM

lee.m.margolis.civ@mail.mil

508-206-2335

Study Officials

• Lee M Margolis, PhD

  Military Nutrition Division, USARIEM

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: FED
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 30, 2018
• First Posted: February 22, 2019
• Study Start: November 28, 2018
• Primary Completion: November 1, 2019
• Study Completion: September 1, 2020
• Last Updated: September 2, 2021
• Results First Posted: September 2, 2021

Record last verified: 2021-08

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)