The Effect of Acute Mild Dehydration on Blood Pressure Control

Study Overview
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Brief Summary
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The goal of this project is determine how acute mild dehydration impacts blood pressure control at rest and during static exercise. This protocol will test healthy young and older adults in a normally hydrated and dehydrated condition.

Detailed Description
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The purpose of this project is determine how acute mild dehydration impacts blood pressure control at rest and during static exercise. Additionally, we will determine whether or not the sympathetic nervous system has a role in mediating blood pressure control at rest and during static exercise. This protocol will test healthy young and older adults in a normally hydrated and dehydrated condition. This will allow for a within participant comparison. Additionally, we will later determine if age alters blood pressure control at rest or during static exercise.

Official Title
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Sympathetic Reactivity to Water Restriction in Young and Older Adults

Conditions
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Mild Dehydration

Intervention / Treatment
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* Other: Normal hydration
* Other: Dehydration


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria (Young): • age: 20-35 years old Exclusion Criteria (Young): high blood pressure (>140/90 mmHg) history of cardiovascular disease history of cancer history of diabetes history of kidney disease obesity (BMI > 30 kg/m2) smoking or tobacco use current pregnancy nursing mothers communication barriers Inclusion Criteria (Older): age: 60-75 years old ECG within normal limits screening blood panel within normal limits Exclusion Criteria (Older): high blood pressure (>140/90 mmHg) history of cardiovascular disease history of cancer history of diabetes history of kidney disease obesity (BMI > 30 kg/m2) smoking or tobacco use current pregnancy nursing mothers communication barriers

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Normal Hydration and Dehydration
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Normal hydration then dehydration<br>Participants will consume water to maintain proper hydration for three days prior to testing (visit 1). Seven to 60 days later, participants will reduce water intake over three days and abstain from any water for the final 16 hours prior to testing (visit 2). | Other: Normal hydration<br>* see description in 'arms'<br>Other: Dehydration<br>* see description in 'arms'<br>|
| Experimental: Dehydration than normal hydration<br>Participants will reduce water intake over three days and abstain from any water for the final 16 hours prior to testing (visit 1). Seven to 60 days later, participants will consume water to maintain proper hydration for three days prior to testing (visit 2). | Other: Normal hydration<br>* see description in 'arms'<br>Other: Dehydration<br>* see description in 'arms'<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood Pressure Variability | Blood pressure variability (BPV) was calculated using standard deviation and using the average real variability index of blood pressure values. The average real variability index calculates the average of absolute differences between consecutive BP measurements and is thought to provide further prognostic value compared with traditional measures of BPV. | During experimental visits 1 and 2 | 
| Blood Pressure Reactivity - Handgrip Exercise | Change in systolic blood pressure during the second-minute handgrip exercise minus compared to pre-exercise baseline (i.e., at rest). | During experimental visits 1 and 2 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Dehydration