NCT03525561

Brief Summary

The goals of the present study are to evaluate whether the most common, and effective, treatment for acute mountain sickness (AMS), acetazolamide (AZ), has a negative, positive, or no influence on exercise performance, cognitive performance, or manual dexterity in young healthy subjects during simulated altitude exposure. AMS represents a serious challenge to the health and performance of the Warfighter who may need to rapidly deploy to high altitude. However, there have been concerns that AZ might alter or impair endurance exercise performance, and possibly fine motor skills. These would represent major limitations to the use of this drug in a Warfighter who has a specific timeframe in which to accomplish mission tasks. In the present project, we will use exposure to simulated altitude in the USARIEM hypobaric chamber to quantify the impact, if any, of AZ on endurance exercise performance following rapid ascent to 3500 meters (m) in unacclimatized lowlander volunteers. The study will be conducted using a randomized, single-blind, placebo-controlled crossover study design. Ten male and female volunteers will complete one orientation day, one VO2peak day, three days of familiarization testing at sea level (SL), then two rounds of experimental testing. Each round of experimental testing consists of six days including four days to establish baseline euhydration, followed by a 30 hour (hr) exposure to 3500 m. Volunteers will have a two week break between experimental testing rounds for washout of any effects of altitude acclimation. During one experimental round, volunteers will take two doses of AZ each day (Phase 1: 250 mg/dose,500 mg/day, Phase 2: 125 mg/dose, 250 mg/day) starting 48 hr prior to their altitude exposure and continuing for the 30 hr stay at high altitude. During the other experimental condition, volunteers will be given a placebo at the same time points as the doses of AZ. Prior to altitude exposure, AMS will be evaluated and volunteers will then ascend to a simulated altitude of 3500 m, where they will remain for 30 hr. Volunteers will rest at altitude for an hr, after which they will complete an AMS questionnaire, resting ventilation measurements, provide a blood sample and complete cognitive and finger dexterity testing. Subjects will then perform 15 minutes (min) of steady state (SS) treadmill exercise at 40-45% of SL VO2peak and a 2 mile treadmill time trial (TT). Volunteers will stay overnight in the hypobaric chamber with research staff supervision. The following morning, metabolic and blood measurements will again be completed, after which volunteers will perform the exercise testing for a second time. Cognitive and finger dexterity testing will be performed before volunteers return to sea level (i.e., "descend" from the simulated altitude). The results of the proposed study will, for the first time, provide quantitative evidence regarding whether AZ treatment impairs endurance exercise performance in the context of a Warfighter-relevant endurance exercise task.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
10

participants targeted

Target at below P25 for early_phase_1

Timeline
Completed

Started Oct 2018

Shorter than P25 for early_phase_1

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

March 16, 2018

Completed
2 months until next milestone

First Posted

Study publicly available on registry

May 15, 2018

Completed
5 months until next milestone

Study Start

First participant enrolled

October 10, 2018

Completed
7 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

May 15, 2019

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

May 15, 2019

Completed
Last Updated

July 5, 2019

Status Verified

July 1, 2019

Enrollment Period

7 months

First QC Date

March 16, 2018

Last Update Submit

July 2, 2019

Conditions

Outcome Measures

Primary Outcomes (1)

  • Endurance exercise performance

    the primary outcome measure is performance of a 2-mile treadmill time trial (self-paced) at simulated altitude.

    Exercise performance will be assessed during a 30-hour simulated altitude exposure, once during placebo and once during acetazolamide administration

Study Arms (2)

acetazolamide arm

ACTIVE COMPARATOR

This is the arm of the study in which the volunteers will take the acetazolamide (Diamox) pill.

Drug: Acetazolamide Pill

placebo arm

PLACEBO COMPARATOR

This is the arm of the study in which volunteers will take the placebo.

Drug: Placebo pill

Interventions

Subjects will take acetazolamide pill (Diamox), 500 mg/ day, and assess effect on exercise performance during 30-hour exposure to 3,500 m simulated altitude.

Also known as: Diamox
acetazolamide arm

Subjects will take placebo pill and then we will assess exercise performance during 30-hour exposure to 3,500 m simulated altitude.

placebo arm

Eligibility Criteria

Age18 Years - 45 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • Volunteers must meet all of the following criteria to be included in the study:
  • Male or female, age 18-45
  • In good health as determined by Office of Medical Support and Oversight (OMSO) General Medical Clearance
  • Passed his/her most recent Army Physical Fitness Test (APFT; military volunteers only) or exercise at least 2 times per week (civilian volunteers)
  • Willing to not exercise, drink alcoholic beverages, or consume caffeinated products for 24 hours before each testing session.
  • Willing not to consume carbonated beverages during the experimental phases of the study (this does not include the two week break between experimental phases)
  • Willing to stay and sleep in an altitude chamber (the size of a dorm room) \~60 hours total (two \~30 hr exposures).
  • Body mass index (BMI) ≤ 28.5

You may not qualify if:

  • Females who are pregnant or planning to become pregnant during the study
  • Taking dietary supplements, prescriptions, or over the counter medication, other than a contraceptive (unless approved by OMSO and PI)
  • 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 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.)
  • Physical problems/injuries associated with walking or running on a treadmill
  • Allergy to skin adhesive
  • Abnormal blood count (For example: hemoglobin (Hb) outside of the normal ranges (Normal \[Hb\] Males = 12.6-17.7 g/dL; Females = 11.1-15.9 g/dL) or hematocrit (Hct) outside of the normal ranges (Normal Hct Males = 37.5-51.0%; Females = 34.0-46.6%) levels, presence of abnormal blood chemicals (hemoglobin S or sickle cell traits)
  • Prior HAPE (high altitude pulmonary edema) or HACE (high altitude cerebral edema) diagnosis
  • Smokers or tobacco/nicotine users (unless have quit more than 4 months prior)
  • Presence of asthma or respiratory tract infections (unless more than 1 month prior or approved by OMSO).
  • Allergy to sulfa drugs (Acetazolamide)
  • Evidence of apnea or other sleeping disorders
  • History of neurologic (e.g. stroke, seizure), speech, facial muscle disorder or injuries preventing from producing normal range of hand and finger motion
  • Experiencing colds, coughs, or sinus infections
  • Food allergies/intolerances to gluten and/or dairy
  • +3 more criteria

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Natick Soldier Systems Center

Natick, Massachusetts, 01760, United States

Location

MeSH Terms

Conditions

Hypoxia

Interventions

Acetazolamide

Condition Hierarchy (Ancestors)

Signs and Symptoms, RespiratorySigns and SymptomsPathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

ThiadiazolesThiazolesSulfur CompoundsOrganic ChemicalsAzolesHeterocyclic Compounds, 1-RingHeterocyclic Compounds

Study Officials

  • Nisha Charkoudian, Ph.D.

    United States Army Research Institute of Environmental Medicine

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
early phase 1
Allocation
RANDOMIZED
Masking
SINGLE
Who Masked
PARTICIPANT
Masking Details
Single-blind use of acetazolamide where participant is not informed. Goal is to evaluate effect (or lack thereof) on exercise performance.
Purpose
BASIC SCIENCE
Intervention Model
CROSSOVER
Model Details: Subjects will serve as their own controls. Will exercise during simulated altitude exposure twice, once with acetazolamide and once with placebo.
Sponsor Type
FED
Responsible Party
SPONSOR

Study Record Dates

First Submitted

March 16, 2018

First Posted

May 15, 2018

Study Start

October 10, 2018

Primary Completion

May 15, 2019

Study Completion

May 15, 2019

Last Updated

July 5, 2019

Record last verified: 2019-07

Locations