Effect of Adding Glycerol to Electrolyte Beverages on Fluid Balance in Healthy Euhydrated Men and Women at Rest

The results of a prior study PEP-2311 suggested there was a positive dose-response effect of glycerol and sodium on fluid balance and fluid retention. In addition, inclusion of glycerol resulted in an upward shift in the relationship between sodium concentration and fluid balance. The practical interpretation is that addition of glycerol enables a reduction in sodium concentration compared with a 0% glycerol drink.

In this follow-up study, the investigators hypothesize that 1) fluid balance will be sustained (greater than or not different from baseline) and significantly greater than placebo for 120 min after drinking the test no/low/moderate carbohydrate beverages and 2) fluid balance will not differ between the carbohydrate-electrolyte beverages, but both will be greater than placebo.

Study Overview

• Status: Recruiting
• Conditions: Fluid Balance
• Intervention / Treatment: Other: Placebo beverage, kiwi-strawberry flavor (Part 1 and Part 2); Other: 0% carbohydrate electrolyte solution with glycerol beverage (Part 1 only); Other: 0% carbohydrate electrolyte solution without glycerol beverage (Part 1 only); Other: 6% carbohydrate electrolyte solution without glycerol beverage (Part 2 only); Other: 1% carbohydrate electrolyte solution with glycerol beverage (Parts 1 and 2); Other: 6% carbohydrate electrolyte solution with glycerol beverage (Parts 1 and 2); Other: 2% carbohydrate electrolyte solution without glycerol beverage (Part 2 only)

Detailed Description

This is a two-part study. Subjects will be asked to complete either Part 1 or Part 2 of this study. Subjects can participate in both parts of the study if they are interested and available to complete all trials. However, they will be asked to complete Part 1 before enrolling in Part 2 of the study. Dosing days are separated by 2-15 days.

Objective 1) To compare the effect of consumption of four no/low/moderate carbohydrate drinks with high electrolyte concentrations vs. placebo on fluid balance at rest. To enroll N=25

Objective 2) To compare the effect of consumption of two moderate carbohydrate drinks with low electrolyte concentrations vs. placebo on fluid balance at rest. To enroll N=70

• Study Type: Interventional
• Enrollment (Estimated): 95
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Lindsay Baker, PhD; Phone Number: 814-883-9454; Email: lindsay.baker@pepsico.com

Study Locations

• United States
  • New York
    • Valhalla, New York, United States, 10595
      • Recruiting
      • PepsiCo R&D, Gatorade Sports Science Institute
      • Contact: Matthew Hinkley, PhD; Phone Number: 914-742-4975; Email: Matt.Hinkley@pepsico.com
      • Contact: Lindsay Baker, PhD; Phone Number: 814-883-9454; Email: lindsay.baker@pepsico.com
      • Principal Investigator: Lindsay Baker, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

Subject is male or female

• If female, subject is not pregnant (based on self-report)
• Subject is 18-50 years of age, inclusive Subject is at least recreationally active (engaged in light to moderate intensity, intermittent, or steady-state exercise at least 3 days per week for at least 30 min at a time)
• Subject does not smoke (or has quit for at least 6 months)
• Subject is not taking medication that may interfere with the study (e.g., diuretics)
• Subject has no health conditions that would interfere with the study, As indicated on the general health questionnaire (GHQ), e.g. cardiovascular, renal, or metabolic diseases
• Subject is not allergic to adhesives (e.g., medical tape)
• Subject is not allergic to kiwi-strawberry flavoring
• Subject is willing to avoid alcohol consumption 24 hours prior to visit(s)
• Subject is willing to fast overnight (~8-12 hours)
• Subject is willing to refrain from vigorous exercise for 24 hours (light physical activity only)
• Subject is willing to eat the exact same food the day prior to each visit to the laboratory
• Able to speak, write, and read English
• Provision of written consent to participate

Exclusion Criteria:

• Subject has participated in a clinical trial within the past 30 days
• Subject has participated in any PepsiCo trial within past 6 months
• Subject has a condition or is taking medication that the investigator believes would interfere with his/her ability to provide informed consent, comply with the study protocol, which might confound the interpretation of the study results, or put the person at undue risk
• Subject is employed by, or has a parent, guardian, or other immediate family member employed by a company that manufactures any products that compete with any Gatorade product. If subject is unsure if a company would be considered a competitor to Gatorade, they will be asked to please let the study investigator know the name of the other company and the nature of their relationship to that company before they sign the informed consent.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

7

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 0% carbohydrate electrolyte solution with glycerol beverage (Part 1 only)	Other: 0% carbohydrate electrolyte solution with glycerol beverage (Part 1 only); 9.3 oz (276 ml) aliquots 3 times for a total of 28 oz (828 ml) over a 35 min period followed by 25 min rest until Time 0 post-dose. Beverage matched to placebo for color and flavor.
Experimental: 0% carbohydrate electrolyte solution without glycerol beverage (Part 1 only)	Other: 0% carbohydrate electrolyte solution without glycerol beverage (Part 1 only); 9.3 oz (276 ml) aliquots 3 times for a total of 28 oz (828 ml) over a 35 min period followed by 25 min rest until Time 0 post-dose. Beverage matched to placebo for color and flavor.
Experimental: 6% carbohydrate electrolyte solution without glycerol beverage (Part 2 only)	Other: 6% carbohydrate electrolyte solution without glycerol beverage (Part 2 only); 9.3 oz (276 ml) aliquots 3 times for a total of 28 oz (828 ml) over a 35 min period followed by 25 min rest until Time 0 post-dose. Beverage matched to placebo for color and flavor.
Placebo Comparator: Placebo beverage (Parts 1 and 2)	Other: Placebo beverage, kiwi-strawberry flavor (Part 1 and Part 2); 9.3 oz (276 ml) aliquots 3 times for a total of 28 oz (828 ml) over a 35 min period followed by 25 min rest until Time 0 post-dose.
Experimental: 1% carbohydrate electrolyte solution with glycerol beverage (Parts 1 and 2)	Other: 1% carbohydrate electrolyte solution with glycerol beverage (Parts 1 and 2); 9.3 oz (276 ml) aliquots 3 times for a total of 28 oz (828 ml) over a 35 min period followed by 25 min rest until Time 0 post-dose. Beverage matched to placebo for color and flavor.
Experimental: 6% carbohydrate electrolyte solution with glycerol beverage (Parts 1 and 2)	Other: 6% carbohydrate electrolyte solution with glycerol beverage (Parts 1 and 2); 9.3 oz (276 ml) aliquots 3 times for a total of 28 oz (828 ml) over a 35 min period followed by 25 min rest until Time 0 post-dose. Beverage matched to placebo for color and flavor.
Experimental: 2% carbohydrate electrolyte solution without glycerol beverage (Part 2 only)	Other: 2% carbohydrate electrolyte solution without glycerol beverage (Part 2 only); 9.3 oz (276 ml) aliquots 3 times for a total of 28 oz (828 ml) over a 35 min period followed by 25 min rest until Time 0 post-dose. Beverage matched to placebo for color and flavor.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fluid balance (Body Weight)	Platform scale to the nearest 0.005 kilograms (kg)	Change each test day from pre-beverage baseline (-60 minutes) to post-beverage Time 0 minutes, 30 minutes, 60 minutes, 90 minutes,120 minutes, and 150 minutes post 3rd (last) beverage
Fluid balance (Percent (%) change in Body Mass)	Platform scale to the nearest 0.005 kilograms (kg)	Change each test day from pre-beverage baseline (-60 minutes) to post-beverage Time 0 minutes, 30 minutes, 60 minutes, 90 minutes,120 minutes, and 150 minutes post 3rd (last) beverage

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fluid retention	Platform scale to the nearest 0.005 kilograms (kg), unit percent (%)	% change each test day from pre-beverage baseline (-60 minutes) to post-beverage Time 0 minutes, 30 minutes, 60 minutes, 90 minutes,120 minutes, and 150 minutes post 3rd (last) beverage
Urine mass	Graduated cylinder on scale to the nearest 0.01 grams	Change each test day from pre-beverage baseline (-60 minutes) to post-beverage Time 0 minutes, 30 minutes, 60 minutes, 90 minutes,120 minutes, and 150 minutes post 3rd (last) beverage
Urine specific gravity	USG digital pen refractometer (Atago), no unit	Change each test day from pre-beverage baseline (-60 minutes) to post-beverage Time 0 minutes, 30 minutes, 60 minutes, 90 minutes,120 minutes, and 150 minutes post 3rd (last) beverage
Blood sodium	Fingerstick sampling, unit millimoles per liter (mmol/L), iSTAT Blood Electrolyte and Chemistry Analyzer (CHEM8+ cartridge)	Change each test day from pre-beverage baseline (-60 minutes) to post-beverage Time 0 minutes, 30 minutes, 60 minutes, 90 minutes,120 minutes, and 150 minutes post 3rd (last) beverage
Blood glucose	Fingerstick sampling, unit milligrams per deciliter (mg/dl), iSTAT Blood Electrolyte and Chemistry Analyzer (CHEM8+ cartridge)	Change each test day from pre-beverage baseline (-60 minutes) to post-beverage Time 0 minutes, 30 minutes, 60 minutes, 90 minutes,120 minutes, and 150 minutes post 3rd (last) beverage
Percent change in plasma volume	Fingerstick sampling, calculated from hematocrit and hemoglobin concentration percent (%)	Change each test day from pre-beverage baseline (-60 minutes) to post-beverage Time 0 minutes, 30 minutes, 60 minutes, 90 minutes,120 minutes, and 150 minutes post 3rd (last) beverage
Serum glycerol concentration	Fingerstick sampling unit millimoles per liter (mmol/L) using Sigma Aldrich glycerol assay kit	Change each test day from pre-beverage baseline (-60 minutes) to post-beverage Time 0 minutes, 30 minutes, 60 minutes, 90 minutes,120 minutes, and 150 minutes post 3rd (last) beverage
Serum osmolality	Fingerstick sampling, unit milliosmoles per kilogram of water (mOsm/Kg H20)	Change each test day from pre-beverage baseline (-60 minutes) to post-beverage Time 0 minutes, 30 minutes, 60 minutes, 90 minutes,120 minutes, and 150 minutes post 3rd (last) beverage
Saliva osmolality	Measured directly from the tongue using a handheld MX3 Diagnostics device, unit milliosmoles per kilogram of water (mOsm/kg H2O)	Change each test day from pre-beverage baseline (-60 minutes) to post-beverage Time 0 minutes, 30 minutes, 60 minutes, 90 minutes,120 minutes, and 150 minutes post 3rd (last) beverage
Blood pressure (systolic/diastolic)	Automatic sphygmomanometer unit millimeters of mercury (mm/Hg)	Change each test day from pre-beverage baseline (-60 minutes) to post-beverage Time 0 minutes, 30 minutes, 60 minutes, 90 minutes,120 minutes, and 150 minutes post 3rd (last) beverage
Heart rate	Heart rate monitor, unit beats per minute (bpm)	Change each test day from pre-beverage baseline (-60 minutes) to post-beverage Time 0 minutes, 30 minutes, 60 minutes, 90 minutes,120 minutes, and 150 minutes post 3rd (last) beverage
Subjective measure of headache	One item on a 100 point visual analog scale anchored from 0=No headache to 100=Severe headache	Change each test day from pre-beverage baseline (-60 minutes) to post-beverage Time 0 minutes, 30 minutes, 60 minutes, 90 minutes,120 minutes, and 150 minutes post 3rd (last) beverage
Subjective measure of lightheadedness	One item on a 100 point visual analog scale anchored from 0=No lightheadedness to 100=Severe lightheadedness	Change each test day from pre-beverage baseline (-60 minutes) to post-beverage Time 0 minutes, 30 minutes, 60 minutes, 90 minutes,120 minutes, and 150 minutes post 3rd (last) beverage
Subjective measures of gastrointestinal discomfort	Eight items on a 100 point visual analog scale (stomach upset, nausea, burping, stomach bloating, abdominal discomfort, stomach fullness, vomiting, diarrhea anchored frrom 0= None to 100=Severe	Change each test day from pre-beverage baseline (-60 minutes) to post-beverage Time 0 minutes, 30 minutes, 60 minutes, 90 minutes,120 minutes, and 150 minutes post 3rd (last) beverage
Menstrual categorization	Using Elliott-Sale chart, 2023 to categorize menstrual/hormonal contraceptive status for those who have not yet reached perimenopause/menopause. This is a decision-tree chart, not a scale.	Assessed at Screening Visit

Collaborators and Investigators

• Sponsor: PepsiCo Global R&D
• Investigators: Principal Investigator: Lindsay Baker, PhD, PepsiCo R&D Life Sciences, Sports Science

Study record dates

Study Major Dates

• Study Start (Actual): September 30, 2024
• Primary Completion (Estimated): May 30, 2025
• Study Completion (Estimated): May 30, 2025

Study Registration Dates

• First Submitted: October 18, 2024
• First Submitted That Met QC Criteria: October 21, 2024
• First Posted (Actual): October 23, 2024

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: February 7, 2025
• Last Verified: February 1, 2025

More Information

Terms related to this study

• Keywords: beverage; electrolytes; hydration; glycerol; carbohtydrate
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Protective Agents; Cryoprotective Agents; Pharmaceutical Solutions; Glycerol
• Other Study ID Numbers: PEP-2412

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No