Three New Ideas to Protect Special Forces From the Stress of High Altitude

March 4, 2021 updated by: University of Colorado, Denver

Acute Mountain Sickness (AMS) is a well-documented syndrome that affects 42% of non-acclimatized individuals traveling to altitudes above 10,000 feet. Decreased barometric pressure, which leads to low blood oxygen levels, is the primary casual factor of AMS. Symptoms of AMS are characterized by headache, nausea, vomiting, dizziness, fatigue and difficultly sleeping. Moreover, when people travel to high altitude, cognitive performance and endurance exercise capacity are impaired. Therefore, the goal of this research is to identify effective pharmacological agents that will help reduce the symptoms of AMS and improve physical and cognitive performance at high altitude.

The investigators will study the efficacy of the dietary supplement, quercetin, the drugs nifedipine (extended release) and methazolamide taken together, the drug metformin, and the drug nitrite in reducing symptoms of AMS and improving cognitive and exercise performance at high altitudes.

Study Overview

Study Type

Interventional

Enrollment (Actual)

148

Phase

  • Phase 4

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

    • Michigan
      • Alma, Michigan, United States, 48801
        • Alma College

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

Ages Eligible for Study

18 years to 30 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Male

Description

Inclusion Criteria:

  • healthy,
  • young (18-30 years old) men who can meet APFT requirements for special operation forces (SOF) training as outlined by the US Army (42 push ups, 53 sit-ups, 6 pull-ups, 2 mile run in < 15 min 54 s)

Exclusion Criteria:

  • women;
  • smokers;
  • participants with diseases or disorders known to be affected by hypoxia or the drugs used in this study, such as hypotension, anemia, sickle cell trait or disease, and diabetes;
  • participants with a history of significant head injury, migraines or seizures;
  • participants taking any medication (over-the-counter or prescription) or herbal supplements;
  • participants with known flavonoid allergies;
  • participants with known allergies to metformin;
  • participants with known hypersensitivity reaction to nifedipine;
  • participants with known allergies to sulfonamide-based drugs;
  • participants with inability to be headache-free when consuming the amount of caffeine in two six ounce cups of coffee or less per day;
  • exposure to high altitude above 1000m in the previous three months; or
  • participants who have been on an airline flight over six hours (the lowered cabin pressure for an extended period of time approximates exposure to high altitude);
  • participants who are unable to achieve the minimum physical criteria required for SOF training

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: Prevention
  • Allocation: Non-Randomized
  • Interventional Model: Factorial Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Quercetin
Quercetin: 500mg pill, twice daily for 5 days
Experimental: Nifedipine+Methazolamide
Nifedipine extended release: 30mg pill, twice daily for 5 days; Methazolamide: 125mg pill, twice daily for 5 days
Experimental: Metformin
Metformin: 500mg pill, once daily for 2 days, then 500mg twice daily at altitude (3 days)
Placebo Comparator: Placebo
Sugar pill manufactured to look like all other investigational products
Experimental: Nitrite
Nitrite: 20mg pill, three times daily for 5 days

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Environmental Symptoms Questionnaire at High Altitude
Time Frame: Baseline and during high altitude exposure (3 days, AM/PM)
Self-reported assessment of AMS symptoms (headache, lightheaded, dizzy, etc.). The 11-item Environmental Symptoms Questionnaire measures Acute Mountain Sickness symptoms (nausea, weakness, lightheadedness, dizziness, headache, etc.). Possible scores range from 0 to 55 (0-5 per item), with higher scores indicating a better outcome.
Baseline and during high altitude exposure (3 days, AM/PM)
Change in Lake Louise AMS Scoring System at High Altitude
Time Frame: Baseline and during high altitude exposure (3 days, AM/PM)
Self-reported assessment of AMS symptoms (headache, nausea, vomiting, dizziness, fatigue and difficultly sleeping). The Lake Louise AMS Scoring System measures symptoms of altitude sickness. Possible scores range from 0 to 16, with higher scores indicating a worse outcome.
Baseline and during high altitude exposure (3 days, AM/PM)
Change in Army Physical Fitness Test (APFT) at High Altitude
Time Frame: Baseline, 1st day at high altitude
Timed 2 mile run, push-ups, sit-ups, and pull-ups. The Army Physical Fitness Test (APFT) measures physical fitness. Higher scores indicate a better outcome. A score of 60 is considered minimum "passing" score. The maximum possible score is 300, indicating the highest level of physical fitness.
Baseline, 1st day at high altitude
Change in Uphill Hike at High Altitude
Time Frame: 2nd day at altitude
Timed 3.1 mile uphill run/hike, with weighted back-pack
2nd day at altitude
Change in Defense Automated Neurobehavioral Assessment (DANA) Reaction Time at High Altitude
Time Frame: Baseline and and 1st day at high altitude
Battery of nine cognitive function tests. The Defense Automated Neurobehavioral Assessment (DANA) measures cognitive function and was used to measure mean reaction time. Possible scores range from 180 to 500 milliseconds, with lower scores indicating a better outcome.
Baseline and and 1st day at high altitude

Collaborators and Investigators

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

Collaborators

Investigators

  • Principal Investigator: Robert Roach, PhD, University of Colorado Anschutz Medical Campus, Altitude Research Center

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)

August 1, 2015

Primary Completion (Actual)

September 1, 2016

Study Completion (Actual)

September 1, 2016

Study Registration Dates

First Submitted

May 29, 2015

First Submitted That Met QC Criteria

June 3, 2015

First Posted (Estimate)

June 4, 2015

Study Record Updates

Last Update Posted (Actual)

March 30, 2021

Last Update Submitted That Met QC Criteria

March 4, 2021

Last Verified

March 1, 2021

More Information

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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