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Vascular Effects of Dietary Potassium

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ClinicalTrials.gov Identifier: NCT03265353
Recruitment Status : Recruiting
First Posted : August 29, 2017
Last Update Posted : January 30, 2018
Sponsor:
Information provided by (Responsible Party):
University of Delaware

Brief Summary:
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.

Condition or disease Intervention/treatment Phase
Cardiovascular Risk Factor Other: Moderate Potassium/Low Sodium Diet Other: Moderate Potassium/High Sodium Diet Other: High Potassium/High Sodium Diet Not Applicable

Detailed Description:
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.

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 75 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Intervention Model Description: All participants will complete each arm. It is a crossover, randomized design.
Masking: None (Open Label)
Primary Purpose: Prevention
Official Title: Vascular Effects of Dietary Potassium in Humans
Actual Study Start Date : July 25, 2013
Estimated Primary Completion Date : July 25, 2019
Estimated Study Completion Date : July 25, 2020

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Potassium

Arm Intervention/treatment
Moderate Potassium/Low Sodium Diet
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
7 days of the prescribed diet

Moderate Potassium/High Sodium Diet
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
7 days of the prescribed diet

High Potassium/High Sodium Diet
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
7 days of the prescribed diet




Primary Outcome Measures :
  1. Conduit artery endothelial-dependent dilation [ Time Frame: on the 7th day of each diet ]
    The change in flow-mediated dilation (FMD) between the 3 diets as assessed by brachial artery FMD


Other Outcome Measures:
  1. Arterial Stiffness [ Time Frame: on 7th day of each diet ]
    Assessed by carotid to femoral artery pulse wave velocity

  2. Wave reflection [ Time Frame: on 7th day of each diet ]
    Assessed by augmentation index

  3. Endothelial cell expression of oxidative stress marker [ Time Frame: on the 7th day of each diet ]
    Assessed in venous endothelial cells from participants.

  4. Ambulatory blood pressure [ Time Frame: 7 days ]
    Assessed by 24 hr ambulatory blood pressure monitoring.



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Ages Eligible for Study:   22 Years to 45 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03265353


Contacts
Contact: Liza J Walker, BS (302)831-3181 lizaj@udel.edu
Contact: Shannon L Lennon, PhD (302)831-2798 slennon@udel.edu

Locations
United States, Delaware
University of Delaware Recruiting
Newark, Delaware, United States, 19716
Contact: Liza Walker, BS    302-831-3181    lizaj@udel.edu   
Sponsors and Collaborators
University of Delaware
Investigators
Principal Investigator: Shannon L Lennon, PhD University of Delaware

Responsible Party: University of Delaware
ClinicalTrials.gov Identifier: NCT03265353     History of Changes
Other Study ID Numbers: 487998-8
First Posted: August 29, 2017    Key Record Dates
Last Update Posted: January 30, 2018
Last Verified: January 2018
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided

Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Keywords provided by University of Delaware:
Potassium
Sodium
Vascular function