The Effect of Water Carbonation on Orthostatic Tolerance

April 22, 2026 updated by: Dr. Victoria Claydon, Simon Fraser University
The primary purpose of this investigation is to determine whether water carbonation can improve orthostatic tolerance in healthy control volunteers. Orthostatic tolerance refers to the ability to maintain an adequate blood pressure when standing. In some individuals blood pressure can fall when standing, predisposing to dizzy spells or fainting episodes. Drinking water can boost blood pressure and making fainting episodes less likely. However, it is not clear whether the carbonation of the water has any further impact on the blood pressure response. This is important because it may be that carbonated water expands the stomach (gastric distension), provoking an increase in sympathetic activity. The increase in sympathetic nervous system activity boosts blood pressure. Resolving this question would have important implications for patients with syncope. This study will test whether carbonated water will have any further impact on blood pressure than the already known effect of non-carbonated water.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

The primary purpose of this investigation is to determine whether water carbonation can improve orthostatic tolerance in healthy control volunteers. Orthostatic tolerance refers to the ability to maintain an adequate blood pressure when standing [1]. In some individuals blood pressure can fall when standing, predisposing to dizzy spells or fainting episodes [1]. Drinking water can boost blood pressure and making fainting episodes less likely [2-8]. However, it is not clear whether the carbonation of the water has any further impact on the blood pressure response [9,10]. This is important because it may be that carbonated water expands the stomach (gastric distension), provoking an increase in sympathetic activity. The increase in sympathetic nervous system activity boosts blood pressure. Resolving this question would have important implications for patients with syncope. This study will test whether carbonated water will have any further impact on blood pressure than the already known effect of non-carbonated water.

Volunteers (n=25) will be asked to undergo a "tilt test" to assess cardiovascular reflex control and orthostatic tolerance (measured as time to presyncope, or near fainting, in minutes). It has been previously shown that this technique to be reproducible, reliable, and to have high sensitivity and specificity for differentiating persons with differing orthostatic tolerance, or for examining the effects of interventions aimed at improving orthostatic tolerance [4,6,11-18].

Volunteers will undergo this test on three separate days. On each day participants will be asked to drink a glass of water: either a 50ml drink of room temperature water (control condition), a 500ml drink of flat (non-carbonated) room temperature water, or a 500ml drink of carbonated room temperature water. The study will be conducted in a randomised, single-blind fashion. The investigator responsible for terminating the test will be blinded as to the water condition on each test day, rendering the study single blind. It will not be possible to blind participants as to the carbonation of the water, however, participants will not be informed as to the hypothesised impact of the water conditions.

Study Type

Interventional

Enrollment (Estimated)

25

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

  • Name: Vera-Ellen M Lucci, PhD
  • Phone Number: 7787828560
  • Email: vlucci@sfu.ca

Study Locations

  • Canada
    • British Columbia
      • Burnaby, British Columbia, Canada, V5A 1S6
        • Recruiting
        • Simon Fraser University
        • Contact:
          • Vera-Ellen M Lucci, PhD
          • Phone Number: 7787828560
          • Email: vlucci@sfu.ca
        • Principal Investigator:
          • Victoria E Claydon, PhD
        • Sub-Investigator:
          • Vera-Ellen M Lucci, PhD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

15 years to 46 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • healthy, English-speaking

Exclusion Criteria:

  • pregnancy or suspected pregnancy, history of cardiovascular disease, history of neurological disease, history of recurrent fainting (≥ 2 episodes of fainting with loss of consciousness in the prior 6 months)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: 500mL carbonated water first, then 500mL of still water, then 50mL of still water
Participants will undergo this test on three separate days. On each day participants will be asked to drink a glass of water: either a 50mL drink of still water (control condition), a 500mL drink of still (non-carbonated) water, or a 500mL drink of carbonated water. In this arm of the study, participants will receive 500mL carbonated water on the first test day, 500mL still water on the second test day, then 50mL still water on the third day.
Other: 500mL carbonated water
Drink 500mL carbonated water immediately prior to head-up tilt test
Other: 500mL still water
Drink 500mL still water immediately prior to head-up tilt test
Other: 50mL still water
Drink 50mL still water immediately prior to head-up tilt test
Experimental: 500mL still water first, then 500 mL carbonated water, then 50mL still water
Participants will undergo this test on three separate days. On each day participants will be asked to drink a glass of water: either a 50mL drink of still water (control condition), a 500mL drink of still (non-carbonated) water, or a 500mL drink of carbonated water. In this arm of the study, participants will receive 500mL still water on the first test day, 500mL carbonated water on the second test day, then 50mL still water on the third day.
Other: 500mL carbonated water
Drink 500mL carbonated water immediately prior to head-up tilt test
Other: 500mL still water
Drink 500mL still water immediately prior to head-up tilt test
Other: 50mL still water
Drink 50mL still water immediately prior to head-up tilt test
Experimental: 500mL carbonated water first, then 50mL of still water, then 500mL of still water
Participants will undergo this test on three separate days. On each day participants will be asked to drink a glass of water: either a 50mL drink of still water (control condition), a 500mL drink of still (non-carbonated) water, or a 500mL drink of carbonated water. In this arm of the study, participants will receive 500mL carbonated water on the first test day, 50mL still water on the second test day, then 500mL still water on the third day.
Other: 500mL carbonated water
Drink 500mL carbonated water immediately prior to head-up tilt test
Other: 500mL still water
Drink 500mL still water immediately prior to head-up tilt test
Other: 50mL still water
Drink 50mL still water immediately prior to head-up tilt test
Experimental: 500mL still water first, then 50mL still water, then 500 mL carbonated water
Participants will undergo this test on three separate days. On each day participants will be asked to drink a glass of water: either a 50mL drink of still water (control condition), a 500mL drink of still (non-carbonated) water, or a 500mL drink of carbonated water. In this arm of the study, participants will receive 500mL still water on the first test day, 50mL still water on the second test day, then 500mL carbonated water on the third day.
Other: 500mL carbonated water
Drink 500mL carbonated water immediately prior to head-up tilt test
Other: 500mL still water
Drink 500mL still water immediately prior to head-up tilt test
Other: 50mL still water
Drink 50mL still water immediately prior to head-up tilt test
Experimental: 50mL still water first, then 500mL still water, then 500 mL carbonated water
Participants will undergo this test on three separate days. On each day participants will be asked to drink a glass of water: either a 50mL drink of still water (control condition), a 500mL drink of still (non-carbonated) water, or a 500mL drink of carbonated water. In this arm of the study, participants will receive 50mL still water on the first test day, 500mL carbonated water on the second test day, then 500mL carbonated water on the third day.
Other: 500mL carbonated water
Drink 500mL carbonated water immediately prior to head-up tilt test
Other: 500mL still water
Drink 500mL still water immediately prior to head-up tilt test
Other: 50mL still water
Drink 50mL still water immediately prior to head-up tilt test
Experimental: 50mL still water first, then 500mL carbonated water, then 500 mL still water
Participants will undergo this test on three separate days. On each day participants will be asked to drink a glass of water: either a 50mL drink of still water (control condition), a 500mL drink of still (non-carbonated) water, or a 500mL drink of carbonated water. In this arm of the study, participants will receive 50mL still water on the first test day, 500mL still water on the second test day, then 500mL still water on the third day.
Other: 500mL carbonated water
Drink 500mL carbonated water immediately prior to head-up tilt test
Other: 500mL still water
Drink 500mL still water immediately prior to head-up tilt test
Other: 50mL still water
Drink 50mL still water immediately prior to head-up tilt test

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Orthostatic tolerance
Time Frame: 0-50 minutes
The time, in minutes, to presyncope (near-fainting) after the initiation of head-up tilt
0-50 minutes

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Simon Fraser University

Investigators

  • Principal Investigator: Victoria E Claydon, PhD, Professor, Biomedical Physiology and Kinesiology

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 1, 2023

Primary Completion (Estimated)

April 1, 2027

Study Completion (Estimated)

April 1, 2027

Study Registration Dates

First Submitted

November 10, 2022

First Submitted That Met QC Criteria

November 10, 2022

First Posted (Actual)

November 18, 2022

Study Record Updates

Last Update Posted (Actual)

April 23, 2026

Last Update Submitted That Met QC Criteria

April 22, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 30000955

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Data will be presented in aggregate form and no identifiers will be included.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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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