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Heat Acclimation and ThermotoleranceNCT01168739

Effect of Combined Exercise, Heat, and Quercetin Supplementation on Whole Body Stress Response

A study testing Quercetin in people with Heat Acclimation and Thermotolerance, run by University of New Mexico at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The purpose of this study is to determine whether dietary quercetin supplementation effects thermotolerance and heat acclimation in human subjects exposed to exercise/heat stress. Specific Aim I. Read more about this study

Who is it for?
Ages 18 to 39 years, men onlyHealthy volunteers can take part
Conditions the study is for
Heat Acclimation and Thermotolerance
What is being tested?
Quercetin
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
9 participants
Where
1 siteUnited States
Study dates
Sep 2009to Mar 2010
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 39 years
  • Men only
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Healthy: 1 or less CV risk factor. Positive risk factors include:
  • Family history
  • Current cigarette smoker or quit within the previous 6 months
  • Hypertension (>140/90 mmHg) or on antihypertensive medication
  • Impaired fasting glucose (>110 mg/dl)
  • Dyslipidemia (LDL>130 mg/dl;HDL<40 mg/dl, total >200 mg/dl)
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  • Low VO2 peak: <40ml/kg/min
  • Overfatness(BMI>30 kg/m2 and/or body fat > 25%)
  • Male
  • 18-39 years of age
  • Willing to follow study diet
  • Willing to exercise for prescribed time
  • Willing to tolerate hot environment
  • Willing to avoid external influences (ambient heat, uv exposure, external exercise) for study duration

Who cannot join

  • History of heat illness
  • Current NSAID use
  • Known gastrointestinal disease
  • Illness (physician provide physical before subject begin each condition)

Trial locations and contacts

1 site in 1 country.

United States1 site
  • UNM General Clinical Research Center

    Albuquerque, New Mexico, 87131

Other trials in United States

About this study

The purpose of this study is to determine whether dietary quercetin supplementation effects thermotolerance and heat acclimation in human subjects exposed to exercise/heat stress.

Specific Aim I. To determine if quercetin in combination with repeated bouts of thermally stressful exercise will impact intestinal barrier function. The investigators will examine urinary lactulose excretion, plasma endotoxin,plasma quercetin, inflammatory cytokines (TNF-a \& Il-6), anti-inflammatory cytokines (Il-10), and HSP70 and HSF-1 content of peripheral blood mononuclear cells.

Specific Aim II. To determine whether quercetin's suppresses the ability of human subjects to acclimate to exercise/heat stress. The investigators will examine body temperatures, heart rates, physiological strain, sweat and plasma volume responses to standardized heat tolerance tests.

Read the detailed description

Overall Protocol:

This study will involve a repeated-measures design (2 conditions) in which subjects will perform exercise in the heat. Each condition will begin with an Intestinal Permeability Measurement (IP1), where subjects will be admitted to the General Clinical Research Center (GCRC), drinking a test solution and collecting their urine for 8 hours to measure intestinal integrity prior to heat stress. This will be followed by a Heat Tolerance Trial (HT1: 50min exercise at 50% VO2max in environmental chamber controlled at 56oC, 20%RF), used as a baseline measurement of subject's capacity to work in the heat. Following HT1 each subject will perform 7 Days of Heat Acclimation (HA)exercise (controlled hyperthermia design, each subject will elevate core temperature >39oC in 50min during 50 minutes of exercise in environmental chamber controlled at 56oC, 20%RF; rest 10 min in environmental chamber; then perform another 50min of exercise at this elevated core temperature). On days 1 and 7 of HA subjects will follow exercise by performing additional Intestinal Permeability Measurements, providing pre (IP2) and post acclimation (IP3) measurements of intestinal permeability. Day 6 of HA will provide a posttest measurement of subjects' capacity to work in the heat, and will be synonymous with Heat Tolerance Trial 2 (HT2).

Subjects will take quercetin during the seven days of HA in one condition, and placebo in the other. At least 1 month must elapse before a subject will be allowed to repeat the opposite condition. The order will be balanced (half will take quercetin first, the other half placebo). This will be a double blinded study. Neither the investigators nor the subjects will know whether a HA involves quercetin or placebo.

Due to the possibility of outside factors causing variations in intestinal permeability over the course of the study, IP1 will always be used as a baseline condition, with IP2 and IP3 being scored relative (as percent change) to the first. Subjects will never be supplemented in IP1, as this might affect basal measurements of permeability. However, because quercetin supplementation may only exert a transient effect on intestinal permeability, subjects will always be supplemented (with either placebo or quercetin, according to condition) in IP2 and IP3.

In all conditions, subjects will be required to follow guidelines on diet and exercise. They will be instructed to avoid caffeine, alcohol, and to stay well hydrated. They will be instructed to avoid exercise that is not directly outlined by the experiment (see attached). Their meals will be provided by the GCRC to ensure adequate nutrition and to avoid high dietary levels of quercetin. We are currently working with BioNutrition on this menu. To ensure compliance with this diet, subjects will fill out a food diary.

Being tested
Quercetin, Placebo
Keywords
thermotolerance, heat acclimation, quercetin, exertional heat illness, gastrointestinal barrier permeability
Medical subject headings
Heat Stress Disorders

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • QuercetinDietary supplement

    2g/d dietary quercetin supplementation, 1g taken am; 1g taken pm

  • PlaceboDietary supplement

    Placebo, performed on same subjects as Quercetin Arm, used to compare results between conditions

Study groups in NCT01168739
Study groupRoleWhat they receive
QuercetinExperimentalnot necessary, contained in protocol
Receives: Dietary Supplement: Quercetin
PlaceboPlacebo comparatornot necessary, contained in protocol
Receives: Dietary Supplement: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Urinary Lactulose Excretion

    Lactulose is a large molecule (disaccharide: 242 kDa) that should not be permeable to the gastrointestinal barrier under normal conditions.

    Subjects will ingest a test solution containing 10 g lactulose (Quintron Instrument Company, QT02500-10-5, Milwaukee, WI, USA) dissolved in 50 ml of distilled water. This is followed by 8 hour urine collection.

    Measured: Baseline

  2. Plasma endotoxin

    Plasma endotoxin will be detected with a standard limulus amebocyte lysate (LAL) kit (Cell Sciences, HIT302, Canton, MA, USA). The minimum and maximum detection limits of this kit are 1.4 pg/ml and 1,000 pg/ml, respectively.

    Measured: Baseline

  3. Plasma Quercetin

    Quercetin conjugates are hydrolysized from plasma with B-glucuronidase and arylsulfatase kit (Roche Diagnostics, 10127698001, Indianapolis, IN, USA). The resulting supernatant is applied to solid phase extraction cartridges and run through a vacuum manifold for purification. The eluent is 80% methanol / 20% 18 MOhm water. Following solid phase extraction chromatographic analysis is performed using high performance liquid chromatography (HPLC).

    Measured: Baseline

  4. Plasma TNF-a

    Measured: pre, post, 2hours post, 4 hours post exercise on Day 1 of exercise/heat stress

  5. plasma Il-6

    Measured: Pre, post, 2hours post, 4 hours post exercise, day 1 of exercise/heat stress

  6. Plasma Il-10

    Measured: Pre, post, 2 hours post, 4 hours post exercise on Day 1 of exercise/heat stress

  7. HSP70 content of peripheral blood mononuclear cells

    Measured: Pre, post, 2 hours post, 4 hours post exercise on day 1 of exercise/heat stress

  8. HSF-1 content of peripheral blood mononuclear cells

    Measured: Pre, post, 2 hours post, 4 hours post exercise on day 1 of exercise/heat stress

  9. Core temperature response to heat tolerance test

    Measured: heat tolerance test 1= before study onset

  10. Skin temperature response to heat tolerance test

    Measured: heat tolerance test 1= before study onset

  11. Mean body temperature response to heat tolerance test

    Measured: heat tolerance test 1= before study onset

  12. Heart rate response to heat tolerance test

    Measured: heat tolerance test 1= before study onset

  13. Physiological strain response to heat tolerance test

    Measured: heat tolerance test 1= before study onset

  14. Urinary Lactulose Excretion

    Measured: Day 1 of exercise/heat stress

  15. Urinary Lactulose Excretion

    Measured: Day 7 of exercise/heat stress

  16. Plasma Quercetin

    Measured: Day 1 of exercise/heat stress

  17. Plasma Quercetin

    Measured: Day 7 of exercise/heat stress

  18. Plasma Endotoxin

    Measured: Day 1 of exercise/heat stress

  19. plasma endotoxin

    Measured: day 7 of exercise/heat stress

  20. Plasma TNF-a

    Measured: pre, post, 2hours post, 4 hours post exercise on Day 7 of exercise/heat stress

  21. plasma Il-10

    Measured: pre, post, 2hours post, 4 hours post exercise on Day 7 of exercise/heat stress

  22. plasma Il-6

    Measured: pre, post, 2hours post, 4 hours post exercise on Day 7 of exercise/heat stress

  23. HSP70 content of peripheral blood mononuclear cells

    Measured: pre, post, 2hours post, 4 hours post exercise on Day 7 of exercise/heat stress

  24. HSF-1 content of peripheral blood mononuclear cells

    Measured: pre, post, 2hours post, 4 hours post exercise on Day 7 of exercise/heat stress

  25. Core temperature response to heat tolerance test

    Measured: heat tolerance trial 2 = day 6 of exercise/heat stress

  26. Skin temperature response to heat tolerance test

    Measured: heat tolerance trial 2 = day 6 of exercise/heat stress

  27. Mean body temperature response to heat tolerance test

    Measured: heat tolerance trial 2 = day 6 of exercise/heat stress

  28. Heart rate response to heat tolerance test

    Measured: heat tolerance trial 2 = day 6 of exercise/heat stress

  29. physiological strain response to heat tolerance test

    Measured: heat tolerance trial 2 = day 6 of exercise/heat stress

Secondary outcomes (4)
  1. Improvements in sweat rate following heat acclimation exercise

    Measured: heat tolerance test 1= before study onset

  2. Plasma volume expansion in response to heat acclimation exercise

    Measured: heat tolerance test 1= before study onset

  3. Improvements in sweat rate following heat acclimation exercise

    Measured: heat tolerance trial 2 = day 6 of exercise/heat stress

  4. plasma volume expansion in response to heat acclimation exercise

    Measured: heat tolerance trial 2 = day 6 of exercise/heat stress

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted23 Jul 2010 (estimated)
  2. Study startSep 2009
  3. Primary completionMar 2010
  4. Study completionMar 2010

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Randomised
Intervention model
Crossover
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
9 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01168739
Sponsor's protocol ID
HRRC08-606
Status last verified
Mar 2024
First submitted
20 Jul 2010
Last updated
12 Mar 2024
Results posted
No
Data monitoring committee
Yes

Questions about this trial

What is this clinical trial studying?

A study testing Quercetin in people with Heat Acclimation and Thermotolerance, run by University of New Mexico at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 14 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 12 Mar 2024. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Urinary Lactulose Excretion (time frame: Baseline). The study lists 29 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Mar 2024.

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