Human Hydration Status Monitoring

NCT ID: NCT01124903

Last Updated: 2020-04-22

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 31 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2009-01-31
• Study Completion Date: 2011-03-31

Brief Summary

The sports medicine literature provides a consensus on what threshold values constitute euhydration (normal body water) using a variety of hydration assessment markers (e.g., blood, urine). The investigators add to this literature by providing decision levels for multiple body fluids which can be used as starting points for diagnosing and treating dehydration. At present, plasma osmolality (Posm) provides the best potential measure for static dehydration assessment (spot measure), while dynamic dehydration assessment (serial monitoring) is best accomplished using change values for Posm, urine specific gravity, or body mass (weight). These findings should be considered useful for clinical, military, and sports medicine communities.

Detailed Description

Well-recognized markers for static (one time) or dynamic (monitoring over time) dehydration assessment have not been rigorously tested for their usefulness in clinical, military, and sports medicine communities.

This study evaluated the components of biological variation and accuracy of potential markers in plasma, urine, saliva, and body mass, for static and dynamic dehydration assessment. Design: Eighteen healthy volunteers (13M, 5F) were studied while carefully controlling hydration and numerous pre-analytical factors. Biological variation was determined over three consecutive days using published methods. Atypical values based on statistical deviations from a homeostatic set-point were examined. Measured deviations in body fluid were produced using a separate, prospective dehydration experiment and evaluated by ROC analysis to quantify diagnostic accuracy.

All dehydration markers displayed substantial individuality and half displayed marked heterogeneity of intra-individual variation. Decision levels for all dehydration markers were within one standard deviation of the ROC criterion values and most were nearly identical to the prospective group means after dehydrating volunteers by 1.8 - 7.0% of body mass. However, only plasma osmolality (Posm) showed statistical promise for use in static dehydration assessment. A 301 ± 5 mmol/kg diagnostic decision level is proposed. Reference change values (RCV) of 9 mmol/kg (Posm), 0.010 (urine specific gravity, Usg), and 2.5% change in body mass (Bm) were also statistically valid for dynamic dehydration assessment at the 95% probability level.

Posm is the only useful marker for static dehydration assessment. Posm, Usg, and Bm are valid markers in the setting of dynamic dehydration assessment.

Conditions

Dehydration

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: SINGLE

Study Groups

Dehydration

Multiple measures of hydration status were made when subjects were normally hydrated (euhydrated) and when dehydrated. The diagnostic usefulness of the measures was determined.

Group Type: EXPERIMENTAL

Dehydration

Intervention Type: PROCEDURE

Subjects were dehydrated by 2 - 7% of body mass over 3-5 hours using exercise-heat stress and fluid restriction.

Interventions

Dehydration

Subjects were dehydrated by 2 - 7% of body mass over 3-5 hours using exercise-heat stress and fluid restriction.

Intervention Type: PROCEDURE

Other Intervention Names

Hypohydration

Eligibility Criteria

Inclusion Criteria

• You are a member of the U.S. Army between 18-39 years of age
• You have passed the APFT within the previous 12 months
• You have completed and passed a recent medical physical exam
• You are willing to discuss with OMSO and the Principle Investigator (PI) all medications and supplements you are taking and you are willing to stop taking any supplements not approved by OMSO and the PI.

Exclusion Criteria

• You have any physical problems that would make exercise difficult
• You have ever had a heat injury or have a history of having trouble in the heat
• You have an allergy to sulfa drugs
• You have been treated for dry eyes
• You are pregnant, planning on becoming pregnant during the study, or are presently lactating

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 39 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

ChromoLogic, LLC

INDUSTRY

Sponsor Role: collaborator

Intelligent Automation, Inc.

INDUSTRY

Sponsor Role: collaborator

Gaia Medical Institute

INDUSTRY

Sponsor Role: collaborator

United States Army Research Institute of Environmental Medicine

FED

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Samuel N Cheuvront, PhD

Role: PRINCIPAL_INVESTIGATOR

United States Army Research Institute of Environmental Medicine

Locations

USARIEM

Natick, Massachusetts, United States

Countries

United States

Other Identifiers

H08-12

Identifier Type: -

Identifier Source: org_study_id