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| Name | Class |
|---|---|
| Georgetown University | OTHER |
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This primary aim of this study was to critically assess whether or not sweat water content and sodium concentration were acutely regulated by dynamic changes in antidiuretic hormone (arginine vasopressin or AVP) acting on the Vasopressin 2 receptor (V2R) during exercise. Secondary aims were to evaluate running performance and core temperature to further characterize the role of AVP in the coordinated balance of fluid and temperature homeostasis during exercise. The primary hypothesis was that activation of the V2R in sweat glands would result in water reabsorption and fluid conservation during endurance exercise.
Ten healthy habitual runners (> 50km running per week) between 18-60 years of age participated in this double blind randomized control trial. Each subject presented to the exercise lab on four separate occasions. Trial 1 was a familiarization trial to determine each subject's maximal aerobic capacity and peak treadmill running speak (VO2 Peak test). Trials 2, 3 and 4 utilized the same exact protocol, differing only in pharmacological intervention. In a randomized, double-blind order (both participant and investigator blinded to the intervention), either a placebo pill, the V2 receptor antagonist tolvaptan (Samsca™, 30mg tablet), or the V2 receptor agonist desmopressin (DDAVP™, 0.2mg tablet) was ingested along with the CorTemp™ Core Temperature Sensor two hours before commencement of the Exercise Trial with 240mL of bottled water. The exercise protocol consisted of 60 minutes of treadmill running at 60% of peak speed (steady-state) followed by a performance test (the VO2 Peak test). Blood, saliva and urine, were collected before the exercise trial (baseline) and again after both the steady-state run and performance runs. Sweat was obtained from sweat patches after both the steady-state and performance runs. Core temperature, fluid intake, performance time, body weight, thirst and sodium palatability ratings were also assessed. Free access to water was allowed during the trial and all urine produced during the trial was measured and collected. The main outcome measure was sweat sodium concentration.
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| all study participants | Experimental | All study participants received all interventions. V2R Antagonist: 30mg Tolvaptan tablet ingested 2 hours before exercise. V2R agonist: 0.2mg DDAVP tablet ingested 2 hours before exercise Placebo |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| V2R (Vasopressin 2 receptor) | Drug | All ten subjects were used as their own controls in this double-blind, randomized controlled trial assessing the effect of the V2R on sweat sodium concentration via use of a V2R blocker (antagonist), stimulator (agonist), against a placebo (drug naive state). |
| Measure | Description | Time Frame |
|---|---|---|
| Sweat Sodium Concentration Obtained After the Steady-state Portion of the Trial | Changes in sweat sodium concentration will parallel changes in urine sodium concentration with use of the V2R antagonist, agonist and placebo if the primary hypothesis is true (sweat sodium is regulated by the V2R, similar to how urine sodium is regulated by principle cells located within in the kidney collecting duct) | 4 study trials (4 weeks) |
| Measure | Description | Time Frame |
|---|---|---|
| Urine Sodium Concentration After the Steady-state Portion of the Trial | Changes in urine sodium concentration after use of the V2R antagonist, agonist and placebo interventions will verify whether or not pharmacologic activation or inhibition was successfully induced. | 4 study trials (4 weeks) |
| Blood Sodium Concentration |
| Measure | Description | Time Frame |
|---|---|---|
| Body Weight | Changes in body weight during the V2R antagonist, agonist and placebo conditions will provide researchers with an additional measure of overall fluid balance (fluid in versus fluid out) as well as an estimate of overall sweat water losses. | 4 trials (4 weeks) |
| Core Temperature |
Inclusion Criteria:
Exclusion Criteria:
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| Name | Affiliation | Role |
|---|---|---|
| Tamara D Hew-Butler, PhD | Oakland University | Principal Investigator |
| Joseph G Verbalis, MD | Georgetown University | Study Director |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| Oakland University | Rochester | Michigan | 48309 | United States |
| PubMed Identifier | Type | Citation | Retractions |
|---|---|---|---|
| 24944242 | Derived | Hew-Butler T, Hummel J, Rider BC, Verbalis JG. Characterization of the effects of the vasopressin V2 receptor on sweating, fluid balance, and performance during exercise. Am J Physiol Regul Integr Comp Physiol. 2014 Aug 15;307(4):R366-75. doi: 10.1152/ajpregu.00120.2014. Epub 2014 Jun 18. |
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Participants received all three interventions in randomized fashion.
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| ID | Title | Description |
|---|---|---|
| FG000 | 1/Placebo, V2R Agonist, V2R Antagonist | This study was a double-blind randomized controlled trial in which all ten subjects participated in three trials under three separate pharmacological interventions: V2R antagonist, agonist and placebo conditions. A standardized exercise protocol was performed in the laboratory, separated by one week. Each subject served as his or her own control and the key which identified which intervention was utilized in the exact order (all tablets customized to appear identical) was unlocked only after data collection was completed. Therefore, all ten subjects participated in a total of thirty intervention exercise trials after the initial treadmill familiarization trial was completed. V2R (Vasopressin 2 receptor): All ten subjects were used as their own controls in this double-blind, randomized controlled trial assessing the effect of the V2R on sweat sodium concentration via use of a V2R blocker (antagonist), stimulator (agonist), against a placebo (drug naive state). |
| Title | Milestones | Reasons Not Completed | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Overall Study |
|
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| ID | Title | Description |
|---|---|---|
| BG000 | 1/Placebo, V2R Agonist, V2R Antagonist | This study was a double-blind randomized controlled trial in which all ten subjects participated in three trials under three separate pharmacological interventions: V2R antagonist, agonist and placebo conditions. A standardized exercise protocol was performed in the laboratory, separated by one week. Each subject served as his or her own control and the key which identified which intervention was utilized in the exact order (all tablets customized to appear identical) was unlocked only after data collection was completed. Therefore, all ten subjects participated in a total of thirty intervention exercise trials after the initial treadmill familiarization trial was completed. V2R (Vasopressin 2 receptor): All ten subjects were used as their own controls in this double-blind, randomized controlled trial assessing the effect of the V2R on sweat sodium concentration via use of a V2R blocker (antagonist), stimulator (agonist), against a placebo (drug naive state). |
| Units | Counts |
|---|---|
| Participants |
|
| Title | Description | Population Description | Parameter Type | Dispersion Type | Unit of Measure | Calculate Percentage | Denominator Units Selected | Denominators | Classes |
|---|---|---|---|---|---|---|---|---|---|
| Age, Continuous | Mean |
| Type | Title | Description | Population Description | Reporting Status | Anticipated Posting Date | Parameter Type | Dispersion Type | Unit of Measure | Calculate Percentage | Time Frame | Units Analyzed | Denominator Units Selected | Arm/Group Information | Denominators | Classes | Analyses | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Primary | Sweat Sodium Concentration Obtained After the Steady-state Portion of the Trial | Changes in sweat sodium concentration will parallel changes in urine sodium concentration with use of the V2R antagonist, agonist and placebo if the primary hypothesis is true (sweat sodium is regulated by the V2R, similar to how urine sodium is regulated by principle cells located within in the kidney collecting duct) | Posted | Mean | Standard Deviation | mEq/L | 4 study trials (4 weeks) |
|
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| ID | Title | Description | Deaths (Affected) | Deaths (At Risk) | Serious Events (Affected) | Serious Events (At Risk) | Other Events (Affected) | Other Events (At Risk) |
|---|---|---|---|---|---|---|---|---|
| EG000 | 1/Placebo, V2R Agonist, V2R Antagonist | This study was a double-blind randomized controlled trial in which all ten subjects participated in three trials under three separate pharmacological interventions: V2R antagonist, agonist and placebo conditions. A standardized exercise protocol was performed in the laboratory, separated by one week. Each subject served as his or her own control and the key which identified which intervention was utilized in the exact order (all tablets customized to appear identical) was unlocked only after data collection was completed. Therefore, all ten subjects participated in a total of thirty intervention exercise trials after the initial treadmill familiarization trial was completed. V2R (Vasopressin 2 receptor): All ten subjects were used as their own controls in this double-blind, randomized controlled trial assessing the effect of the V2R on sweat sodium concentration via use of a V2R blocker (antagonist), stimulator (agonist), against a placebo (drug naive state). |
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| Title | Organization | Phone | Extension | |
|---|---|---|---|---|
| Tamara Hew-Butler | Oakland University | 248-364-8686 | hew@oakland.edu |
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| ID | Term |
|---|---|
| D007010 | Hyponatremia |
| D006955 | Hypernatremia |
| D003919 | Diabetes Insipidus |
| ID | Term |
|---|---|
| D014883 | Water-Electrolyte Imbalance |
| D008659 | Metabolic Diseases |
| D009750 | Nutritional and Metabolic Diseases |
| D007674 | Kidney Diseases |
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| ID | Term |
|---|---|
| D013607 | Tablets |
| ID | Term |
|---|---|
| D004304 | Dosage Forms |
| D004364 | Pharmaceutical Preparations |
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|
|
Measurement of blood sodium concentration will determine if normonatremia (blood sodium concentrations within the normal physiological range of 135-145mmol/L) were maintained throughout the trial with appropriate fluid intake during the V2R antagonist, agonist and placebo intervention trials. |
| 4 study trials (4 weeks) |
| Saliva Sodium Concentration | Measurement of salivary sodium concentration will allow us to determine if the V2R antagonist, agonist and placebo interventions activate aquaporin-5 (AQP5) water channels that are also located in sweat glands. If the V2R acts on the sweat glands through AQP5, there should be parallel changes in sweat, urine and saliva sodium concentrations with each pharmaceutical intervention. | 4 trials (4 weeks) |
Measurement of core temperature using an ingestible CorTemp sensor during the V2R antagonist, agonist and placebo trials will allow researchers to assess if fluid homeostasis and thermoregulation were intertwined in response to each pharmacological intervention. |
| 4 trials (4 weeks) |
| Thirst Rating | To determine if fluid intake behaviors were appropriately regulated in response to the V2R antagonist, agonist and placebo conditions during exercise. | 4 trials (4 weeks) |
| Sodium Palatability Ratings | To determine if sodium preference ratings were appropriately regulated in response to the V2R antagonist, agonist and placebo conditions during exercise. | 4 weeks (4 trials) |
| Performance | To determine if exercise performance, as determined by overall exercise time, was affected in response to the V2R antagonist, agonist and placebo conditions. | 4 trials (4 weeks) |
| Fluid Intake | To determine if fluid intake behaviors were appropriately regulated in response to the V2R antagonist, agonist and placebo conditions during exercise. | 4 weeks (4 trials) |
| years |
|
| Sex: Female, Male | Count of Participants | Participants |
|
| Region of Enrollment | Number | participants |
|
| years of running experience | Mean | Standard Deviation | years |
|
| BMI | Mean | Standard Deviation | kg/m2 |
|
| VO2 Peak | Mean | Standard Deviation | ml/kg/minute |
|
| Peak treadmill running speed | Mean | Standard Deviation | mph |
|
|
|
| Secondary | Urine Sodium Concentration After the Steady-state Portion of the Trial | Changes in urine sodium concentration after use of the V2R antagonist, agonist and placebo interventions will verify whether or not pharmacologic activation or inhibition was successfully induced. | Posted | Mean | Standard Deviation | mEq/L | 4 study trials (4 weeks) |
|
|
|
| Secondary | Blood Sodium Concentration | Measurement of blood sodium concentration will determine if normonatremia (blood sodium concentrations within the normal physiological range of 135-145mmol/L) were maintained throughout the trial with appropriate fluid intake during the V2R antagonist, agonist and placebo intervention trials. | Posted | Mean | Standard Deviation | mEq/L | 4 study trials (4 weeks) |
|
|
|
| Secondary | Saliva Sodium Concentration | Measurement of salivary sodium concentration will allow us to determine if the V2R antagonist, agonist and placebo interventions activate aquaporin-5 (AQP5) water channels that are also located in sweat glands. If the V2R acts on the sweat glands through AQP5, there should be parallel changes in sweat, urine and saliva sodium concentrations with each pharmaceutical intervention. | Posted | Mean | Standard Deviation | mEq/L | 4 trials (4 weeks) |
|
|
|
| Other Pre-specified | Body Weight | Changes in body weight during the V2R antagonist, agonist and placebo conditions will provide researchers with an additional measure of overall fluid balance (fluid in versus fluid out) as well as an estimate of overall sweat water losses. | Not Posted | 4 trials (4 weeks) |
| Other Pre-specified | Core Temperature | Measurement of core temperature using an ingestible CorTemp sensor during the V2R antagonist, agonist and placebo trials will allow researchers to assess if fluid homeostasis and thermoregulation were intertwined in response to each pharmacological intervention. | Not Posted | 4 trials (4 weeks) |
| Other Pre-specified | Thirst Rating | To determine if fluid intake behaviors were appropriately regulated in response to the V2R antagonist, agonist and placebo conditions during exercise. | Not Posted | 4 trials (4 weeks) |
| Other Pre-specified | Sodium Palatability Ratings | To determine if sodium preference ratings were appropriately regulated in response to the V2R antagonist, agonist and placebo conditions during exercise. | Not Posted | 4 weeks (4 trials) |
| Other Pre-specified | Performance | To determine if exercise performance, as determined by overall exercise time, was affected in response to the V2R antagonist, agonist and placebo conditions. | Not Posted | 4 trials (4 weeks) |
| Other Pre-specified | Fluid Intake | To determine if fluid intake behaviors were appropriately regulated in response to the V2R antagonist, agonist and placebo conditions during exercise. | Not Posted | 4 weeks (4 trials) |
| 0 |
| 10 |
| 0 |
| 10 |
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| D014570 | Urologic Diseases |
| D052776 | Female Urogenital Diseases |
| D005261 | Female Urogenital Diseases and Pregnancy Complications |
| D000091642 | Urogenital Diseases |
| D052801 | Male Urogenital Diseases |
| D010900 | Pituitary Diseases |
| D004700 | Endocrine System Diseases |
| Title | Measurements |
|---|---|
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| Title | Measurements |
|---|---|
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