Mechanisms Underlying the Protective Vascular Effects of Dietary Potassium in Humans

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.

Study Overview

• Status: Recruiting
• Conditions: Cardiovascular Risk Factor
• Intervention / Treatment: Other: Moderate Potassium/Low Sodium Diet; Other: Moderate Potassium/High Sodium Diet; Other: High Potassium/High Sodium Diet

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Estimated): 90
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Liza J Walker, BS; Phone Number: (302)831-3181; Email: lizaj@udel.edu
• Study Contact Backup: Name: Shannon L Lennon, PhD; Phone Number: 3028312798; Email: slennon@udel.edu

Study Locations

• United States
  • Delaware
    • Newark, Delaware, United States, 19716
      • Recruiting
      • University of Delaware
      • Contact: Liza Walker, BS; Phone Number: 302-831-3181; Email: lizaj@udel.edu
      • Contact: Shannon L Lennon, PhD; Phone Number: 3028312798; Email: slennon@udel.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

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

What is the study measuring?

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

Collaborators and Investigators

• Sponsor: University of Delaware
• Investigators: Principal Investigator: Shannon L Lennon, PhD, University of Delaware

Study record dates

Study Major Dates

• Study Start (Actual): January 16, 2020
• Primary Completion (Estimated): August 30, 2024
• Study Completion (Estimated): December 31, 2024

Study Registration Dates

• First Submitted: September 23, 2019
• First Submitted That Met QC Criteria: September 23, 2019
• First Posted (Actual): September 24, 2019

Study Record Updates

• Last Update Posted (Actual): June 1, 2023
• Last Update Submitted That Met QC Criteria: May 30, 2023
• Last Verified: May 1, 2023

More Information

Terms related to this study

• Keywords: Dietary Sodium; Vascular Health; Dietary Potassium
• Other Study ID Numbers: 1472577

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No