The Potassium Supplementation Study

Study Overview
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Brief Summary
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This study will test whether potassium supplementation can reduce the deleterious effect of a high sodium diet on blood vessel function, blood pressure reactivity and autonomic nervous system function in apparently healthy adults.

Detailed Description
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Excess sodium intake is linked to poor blood pressure (BP) regulation and endothelial dysfunction, both of which are implicated in the pathogenesis of atherosclerosis and high BP. Evidence suggests potassium may offset the damaging effects of sodium; however, studies in healthy adults are lacking. This is important as these pre-clinical risk factors have been observed in this population, suggesting early intervention may be critical for cardiovascular disease prevention. High potassium diets have been effective at attenuating a sodium-induced decline in endothelial function. However, potassium intake was increased using whole foods; thus, the vascular benefits cannot be attributed solely to potassium. Furthermore, whether potassium can reduce sodium-induced oxidative stress is unknown. The central hypothesis of this study is that endothelial function will be greater and BP reactivity and oxidative stress will be lower with a high potassium intake compared to a low potassium intake, in the context of a high sodium diet. The investigators will assess macrovascular function using flow-mediated dilation, BP reactivity using the cold pressor test and isometric handgrip grip test, and oxidative stress using electron paramagnetic resonance.

Official Title
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The Role of Potassium Supplementation on Endothelial Function, BP Regulation, and Oxidative Stress Under High Sodium Conditions

Conditions
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Cardiovascular Health, Cardiovascular Risk Factor

Intervention / Treatment
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* Dietary Supplement: Potassium chloride supplement
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: men and women 18-45 years of age all races/ethnicities BMI < 30 kg/m2 BP < 130/80 mmHg Exclusion Criteria: presence of hypertension known heart disease diabetes kidney disease cancer inflammatory conditions blood clotting disorders pregnancy adrenal gland disorder history of stomach or intestinal bleeding history of kidney stones serum potassium outside of the normal range

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 all arms in a randomized, crossover design.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Moderate potassium/low sodium<br>Subjects will consume a diet moderation in potassium and low in sodium. | Dietary Supplement: Placebo<br>* Subjects will receive a placebo capsule on the moderate potassium/low sodium diet and the moderate potassium/high sodium diet<br>|
| Experimental: Moderate potassium/high sodium<br>Subjects will consume a diet moderation in potassium and high in sodium. | Dietary Supplement: Placebo<br>* Subjects will receive a placebo capsule on the moderate potassium/low sodium diet and the moderate potassium/high sodium diet<br>|
| Experimental: High potassium/high sodium<br>Subjects will consume a diet moderation in potassium and high in sodium. | Dietary Supplement: Potassium chloride supplement<br>* Subjects will receive 64 mmol of KCl on the high potassium/high sodium condition.<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 difference in flow-mediated dilation (FMD) between the 3 diets | on day 10 of each diet | 
| Blood pressure reactivity | The change in both systolic and diastolic blood pressure during handgrip exercise and cold pressor test from baseline | on day 10 of each diet | 
| Superoxide levels | The difference in superoxide levels as measured by electronic paramagnetic resonance (EPR) between the 3 diets will be assessed | on day 10 of each diet |