- ICH GCP
- US Clinical Trials Registry
- Clinical Trial NCT01434979
Exertional Heat Illness: Biomarkers for Prediction and Return to Duty (Heat3)
Study Overview
Status
Conditions
Detailed Description
Purpose: Our goal is to monitor and quantify the differential physiologic and biomarker responses of controls to standardized exercise under thermoneutral and thermally challenged conditions and responses of exertional heat stroke (EHS) subjects under a thermal-challenged environment to develop unique biosignature panels to predict those at risk for exertional heat illness (EHI) and guide return to duty following an episode of EHS.
Research Design: This is a prospective cross-sectional study.
Methodology/Technical Approach: The proposed study will examine multiple biomarkers in a group of 100 individuals who have not had an episode of EHS and a prospective study of 50 persons who have had an EHS event. Control subjects will have biomarker assessments before and after an exercise challenge under thermoneutral (TTT) and thermally challenged conditions (heat tolerance test/HTT); differences in the responses to the two tests will be attributed to the heat. In EHS subjects, blood will be obtained at time of injury and then followed up at 6 weeks according to non-EHS controls. In addition, EHS cases will be prospectively followed at 3, 6, 12, and 18 months after the 6-week post assessment. If they are heat tolerant at 6-weeks as determined by a HTT, subsequent measures will include only blood samples and questionnaires, whereas if they are heat intolerant (HIT) at 6-weeks, subsequent measures will include additional HTTs, along with blood samples and questionnaires. As our previous data indicate, approximately 20% of non-EHS persons are HIT; we will test 100 non-EHS and 50 EHI persons in this study. Thus, data will be evaluated with regard to thermotolerance. Importantly, all control participants will undergo two test sessions (HTT and TTT); to control for an order effect, we will randomize the tests.
Study Type
Enrollment (Actual)
Contacts and Locations
Study Locations
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Tel-Hashomer, Israel
- Heller Institute of Medical Research
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Maryland
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Bethesda, Maryland, United States, 20814
- Uniformed Services University of the Health Sciences
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Participation Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Genders Eligible for Study
Sampling Method
Study Population
Description
Inclusion Criteria:
- Federal Civilian Employee, Active Duty, or DoD Beneficiary
- Between the ages of 18 and 45 years
- Waist circumference ≤ 39.4 inches (100 cm)
- Willing to walk/run on a treadmill
- Willing to undergo exposure in a thermal chamber
- Willing to maintain their current activity patterns, and to abstain from alcohol, caffeine, and tobacco for 24 hours prior to all sessions
- For cases who have suffered from a exertional heat illness / exertional heat stroke, must have a clinically documented heat stroke within the past year
Exclusion Criteria:
- History of malignant hyperthermia
- Pregnant or lactating
- Have overt heart disease
- Have systolic blood pressure over 140 mm Hg, or diastolic pressure over 90 mm Hg
- Have a waist circumference > 39.4 inches (100 cm)
- Are older than 45 or younger than 18 years of age
- Are anemic
- Are taking psychotropic medication for any mental health disorder
- Are taking other selected medications (glucose lowering, prednisone or beta blockers)
Study Plan
How is the study designed?
Design Details
- Observational Models: Case-Control
- Time Perspectives: Prospective
Cohorts and Interventions
Group / Cohort |
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Controls
Active Duty,DoD Beneficiary, or civilian men and women between the ages of 18 and 45 years, with a waist circumference ≤ 39.4 inches (100 cm) will be asked to participate.
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Exertional Heat Illness / Stroke
Active duty men and women between the ages of 18 and 45 years will be asked to participate.
They must have a clinically documented heat stroke within the last year; they will not be tested any sooner than six weeks following the heat stroke.
Heat stroke for the purpose of this study is defined as: a syndrome of hyperthermia, physical collapse or debilitation, and encephalopathy as evidenced by delirium, stupor, or coma, occurring during or immediately following exertion or significant heat exposure.
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What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
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Heat tolerance
Time Frame: 2-hour heat test
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Heat tolerance is determined by physiologic response to a 2-hour heat tolerance test.
During this test, participants with core temperature greater than 38.5 C and/or heart rate greater than 150 bpm are considered heat intolerant.
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2-hour heat test
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Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
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Fitness
Time Frame: 2-hour heat tolerance test
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Body fat and aerobic capacity will be measured to quantify their contribution to heat tolerance.
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2-hour heat tolerance test
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Behavioral correlates of heat tolerance
Time Frame: past month
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Questionnaires will be used to assess behavioral correlates of heat tolerance, including measures of sleep impairment and executive dysfunction.
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past month
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Perceived heat strain
Time Frame: 2-hour heat tolerance test and 2-hour control test
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Measures of perceived heat strain will be recorded to determine how accurately participants perceive that they are working in the heat, and whether this adds diagnostic value to the heat test.
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2-hour heat tolerance test and 2-hour control test
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Other Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
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Blood pressure in response to heat tolerance
Time Frame: 2-hour heat tolerance test and 2-hour control test
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Blood pressure will be recorded to see whether it blood pressure response to exercise in the heat correlates with heat tolerance.
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2-hour heat tolerance test and 2-hour control test
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Collaborators and Investigators
Investigators
- Principal Investigator: Patricia Deuster, PhD, MPH, Uniformed Services University of the Health Sciences
Study record dates
Study Major Dates
Study Start
Primary Completion (Actual)
Study Completion (Actual)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Estimate)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Additional Relevant MeSH Terms
Other Study ID Numbers
- G191FY
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
product manufactured in and exported from the U.S.
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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