Vascular Effects of Dietary Potassium

Study Overview
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Brief Summary
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The purpose of this study is to determine if dietary potassium can attenuate the deleterious effects of high sodium on blood vessel function in healthy, salt-resistant participants.

Detailed Description
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Cardiovascular disease remains a major Public Health problem in the U.S. and is the result of diseases such as atherosclerosis and high blood pressure (BP). Several dietary factors have been implicated as risk factors including high sodium and low potassium diets. Indeed, it is well known that excess sodium can increase BP while potassium rich diets have BP lowering properties. 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. Data in animal models suggest that salt loading, independent of changes in BP, results in endothelial dysfunction while evidence is mounting that potassium may be beneficial to vascular health. Further, potassium may be more effective in the presence of high sodium however the role of potassium in protecting the vasculature from a high sodium diet in salt-resistant adults has not been explored. A potential mechanism responsible for sodium induced vascular dysfunction is overproduction of reactive oxygen species resulting in reduced nitric oxide (NO) production/ bioavailability. It has been suggested that potassium can counteract sodium's effect by reducing ROS. The central hypothesis is that potassium can protect against the deleterious effects of high sodium on the vasculature by reducing oxidative stress and preserving NO. In this grant, the investigators propose to use a 21-day controlled feeding study to compare the effects of a high sodium diet (300 mmol) combined with either a high (120 mmol) or moderate (65 mmol) amount of potassium and low sodium (50 mmol) combined with moderate potassium (crossover design, diet order sequence randomized) on 2 levels of the vasculature, conduit artery and microvasculature. These experiments will be performed in salt-resistant participants to study the vascular effects alone, independent of changes in BP.

Official Title
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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 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: 22 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 |
| --- | --- |
| Other: Moderate Potassium/Low Sodium Diet<br>Vascular function will be assessed at both the conduit artery and microvascular level after 7 days of the moderate potassium/low sodium diet. | Other: Moderate Potassium/Low Sodium Diet<br>* 7 days of the prescribed diet<br>|
| Other: Moderate Potassium/High Sodium Diet<br>Vascular function will be assessed at both the conduit artery and microvascular level after 7 days of the moderate potassium/high sodium diet. | Other: Moderate Potassium/High Sodium Diet<br>* 7 days of the prescribed diet<br>|
| Other: High Potassium/High Sodium Diet<br>Vascular function will be assessed at both the conduit artery and microvascular level after 7 days of the high potassium/high sodium diet. | Other: High Potassium/High Sodium Diet<br>* 7 days of the prescribed diet<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 the 7th day of each diet | 

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