Mechanisms Underlying the Protective Vascular Effects of Dietary Potassium in Humans

Study Overview
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Brief Summary
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Americans continue to consume high amounts of sodium. Potassium is notable for its blood pressure lowering effects but less is known regarding its effect on the vasculature. This investigation seeks to determine the role of dietary potassium on the vasculature in the presence of a high sodium diet in salt-resistant adults.

Detailed Description
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Significant public health efforts have been made towards salt reduction but most have met with failure. Dietary factors such high sodium/low potassium diets contribute to the development of cardiovascular diseases (CVDs) such as atherosclerosis and high blood pressure (BP). This is important as CVD is the number one killer in the U.S. While the role of these two nutrients on BP is widely accepted, their impact on the vasculature has received less attention. Endothelial dysfunction, characterized by impaired dilation, is an important non-traditional risk factor for atherosclerosis. Evidence supporting potassium's beneficial role on vascular health remains unclear although it may be more effective in the presence of a high sodium diet. A purported mechanism responsible for sodium-induced vascular dysfunction is overproduction of reactive oxygen species (ROS) resulting in reduced nitric oxide (NO) production/bioavailability. Additionally, high sodium diets have been shown to stiffen the endothelium. This investigation will evaluate the vascular effects of dietary potassium during a high salt diet including its impact on sodium-induced oxidative stress and endothelial cell stiffness.

Official Title
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Mechanisms Underlying the Protective Vascular Effects of Dietary Potassium in Humans

Conditions
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Cardiovascular Risk Factor

Intervention / Treatment
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* Other: Moderate Potassium/Low Sodium Diet
* Other: Moderate Potassium/High Sodium Diet
* Other: High Potassium/High Sodium Diet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy normal blood pressure normal resting ECG Exclusion Criteria: hypertension history of heart disease diabetes kidney disease obese (BMI ≥30) significant weight changes in the last 6 months use of tobacco products pregnant on a special diet (gluten free; vegan) take any medications for the above conditions endurance trained athletes

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 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: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: All participants will complete each arm. It is a crossover, randomized design.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Moderate Potassium/Low Sodium<br>Subjects will be provided with a diet that is moderate in potassium and low in sodium. | Other: Moderate Potassium/Low Sodium Diet<br>* Consumption of 10 days of a diet moderate in potassium and low in sodium.<br>|
| Experimental: Moderate Potassium/High Sodium<br>Subjects will be provided with a diet that is moderate in potassium and high in sodium. | Other: Moderate Potassium/High Sodium Diet<br>* Consumption of 10 days of a diet moderate in potassium and high in sodium.<br>|
| Experimental: High Potassium/High Sodium<br>Subjects will be provided with a diet that is high in both potassium and sodium. | Other: High Potassium/High Sodium Diet<br>* Consumption of 10 days of a diet high in potassium and high in sodium.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Conduit artery endothelial-dependent dilation | The change in flow-mediated dilation (FMD) between the 3 diets as assessed by brachial artery FMD | on day 10 of the diet | 
| Microvascular function | Cutaneous microvascular dilatory response to local heating assessed by laser Doppler flowmetry coupled with intradermal microdialysis | on day 10 of the diet | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ambulatory BP monitoring | assessed by 24-hour ambulatory blood pressure | on day 7 and 10 of diet | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Dietary Potassium, Dietary Sodium, Vascular Health