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

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.

Study Overview

• Status: Completed
• Conditions: Heat Acclimation and Thermotolerance
• Intervention / Treatment: Dietary supplement: Quercetin; Dietary supplement: Placebo

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.

• Study Type: Interventional
• Enrollment (Actual): 9
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • New Mexico
    • Albuquerque, New Mexico, United States, 87131
      • UNM General Clinical Research Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 39 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• 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)
  • 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

Exclusion Criteria:

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Quercetin; not necessary, contained in protocol	Dietary supplement: Quercetin; 2g/d dietary quercetin supplementation, 1g taken am; 1g taken pm
Placebo Comparator: Placebo; not necessary, contained in protocol	Dietary supplement: Placebo; Placebo, performed on same subjects as Quercetin Arm, used to compare results between conditions

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	Baseline
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.	Baseline
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).	Baseline
Plasma TNF-a		pre, post, 2hours post, 4 hours post exercise on Day 1 of exercise/heat stress
plasma Il-6		Pre, post, 2hours post, 4 hours post exercise, day 1 of exercise/heat stress
Plasma Il-10		Pre, post, 2 hours post, 4 hours post exercise on Day 1 of exercise/heat stress
HSP70 content of peripheral blood mononuclear cells		Pre, post, 2 hours post, 4 hours post exercise on day 1 of exercise/heat stress
HSF-1 content of peripheral blood mononuclear cells		Pre, post, 2 hours post, 4 hours post exercise on day 1 of exercise/heat stress
Core temperature response to heat tolerance test		heat tolerance test 1= before study onset
Skin temperature response to heat tolerance test		heat tolerance test 1= before study onset
Mean body temperature response to heat tolerance test		heat tolerance test 1= before study onset
Heart rate response to heat tolerance test		heat tolerance test 1= before study onset
Physiological strain response to heat tolerance test		heat tolerance test 1= before study onset
Urinary Lactulose Excretion		Day 1 of exercise/heat stress
Urinary Lactulose Excretion		Day 7 of exercise/heat stress
Plasma Quercetin		Day 1 of exercise/heat stress
Plasma Quercetin		Day 7 of exercise/heat stress
Plasma Endotoxin		Day 1 of exercise/heat stress
plasma endotoxin		day 7 of exercise/heat stress
Plasma TNF-a		pre, post, 2hours post, 4 hours post exercise on Day 7 of exercise/heat stress
plasma Il-10		pre, post, 2hours post, 4 hours post exercise on Day 7 of exercise/heat stress
plasma Il-6		pre, post, 2hours post, 4 hours post exercise on Day 7 of exercise/heat stress
HSP70 content of peripheral blood mononuclear cells		pre, post, 2hours post, 4 hours post exercise on Day 7 of exercise/heat stress
HSF-1 content of peripheral blood mononuclear cells		pre, post, 2hours post, 4 hours post exercise on Day 7 of exercise/heat stress
Core temperature response to heat tolerance test		heat tolerance trial 2 = day 6 of exercise/heat stress
Skin temperature response to heat tolerance test		heat tolerance trial 2 = day 6 of exercise/heat stress
Mean body temperature response to heat tolerance test		heat tolerance trial 2 = day 6 of exercise/heat stress
Heart rate response to heat tolerance test		heat tolerance trial 2 = day 6 of exercise/heat stress
physiological strain response to heat tolerance test		heat tolerance trial 2 = day 6 of exercise/heat stress

Secondary Outcome Measures

Outcome Measure	Time Frame
Improvements in sweat rate following heat acclimation exercise	heat tolerance test 1= before study onset
Plasma volume expansion in response to heat acclimation exercise	heat tolerance test 1= before study onset
Improvements in sweat rate following heat acclimation exercise	heat tolerance trial 2 = day 6 of exercise/heat stress
plasma volume expansion in response to heat acclimation exercise	heat tolerance trial 2 = day 6 of exercise/heat stress

Collaborators and Investigators

• Sponsor: University of New Mexico
• Collaborators: Quercegen Pharmaceuticals; Gatorade Sports and Science Institute
• Investigators: Principal Investigator: Pope L Moseley, MD, University of New Mexico, Professor and Chariman, Dpt of Internal Medicine; Study Director: Matthew R. Kuennen, PhD, UNM Department of Health, Exercise and Sports Sciences and UNM Department of Internal Medicine

Study record dates

Study Major Dates

• Study Start: September 1, 2009
• Primary Completion (Actual): March 1, 2010
• Study Completion (Actual): March 1, 2010

Study Registration Dates

• First Submitted: July 20, 2010
• First Submitted That Met QC Criteria: July 21, 2010
• First Posted (Estimated): July 23, 2010

Study Record Updates

• Last Update Posted (Actual): March 12, 2024
• Last Update Submitted That Met QC Criteria: March 9, 2024
• Last Verified: March 1, 2024

More Information

Terms related to this study

• Keywords: thermotolerance; heat acclimation; quercetin; exertional heat illness; gastrointestinal barrier permeability
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Protective Agents; Antioxidants; Quercetin
• Other Study ID Numbers: HRRC08-606

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No