Dietary Sodium, Oxidative Stress, and Pulsatile Hemodynamics

The Role of Oxidative Stress and Endothelial Dysfunction in High Sodium-Induced Changes in Pulsatile Hemodynamics

High sodium diets impair vascular function, which may influence the work of the heart. This investigation is designed to determine if this change in vascular function results in a greater workload in the heart and if people who regularly exercise are protected from these effects.

Study Overview

• Status: Recruiting
• Conditions: Sodium Excess
• Intervention / Treatment: Dietary supplement: High Sodium; Other: Placebo

Detailed Description

Excess dietary sodium is associated with cardiac hypertrophy independent of changes in blood pressure. Importantly, increased arterial pulsatile load predicts left ventricular hypertrophy, and thus presents a potential mechanism through which high dietary sodium augments cardiovascular disease risk.

While high sodium diets impair vascular function via an increase in oxidative stress, how high sodium influences central pulsatile hemodynamics is not known. This project aims to a) determine how impaired vascular function affects pulsatile hemodynamics and thus influences the work of the heart during periods of high sodium consumption and b) examine whether regular aerobic exercise and/or fitness protects against the deleterious effects of excess sodium.

• Study Type: Interventional
• Enrollment (Estimated): 50
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: David G Edwards, PhD; Phone Number: 302-831-3363; Email: dge@udel.edu
• Study Contact Backup: Name: Jordan C Patik, PhD; Phone Number: 512-820-6387; Email: jpatik@udel.edu

Study Locations

• United States
  • Delaware
    • Newark, Delaware, United States, 19713
      • Recruiting
      • Department of Kinesiology and Applied Physiology, University of Delaware
      • Contact: David Edwards, PhD; Email: dge@udel.edu
      • Principal Investigator: David Edwards, PhD
      • Contact: Jordan Patik, PhD; Email: jpatik@udel.edu
      • Principal Investigator: Jordan Patik, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years to 45 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Healthy individuals (age 21-45) who are either sedentary (1 or less days of exercise per week during past year) or habitually active (4 or more days of aerobic exercise per week for a minimum of 1 year)

Exclusion Criteria:

• Body mass index <18 or >35
• Systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90
• Blood donation within past 8 weeks,
• Glucose 6 phosphate dehydrogenase (G6PD) deficiency
• A history of cancer, diabetes, or any other chronic disease
• A history of any heart disease
• A history of hormone therapy
• Use of nicotine products
• Pregnancy
• Nursing mothers
• Participation in regular physical activity greater than 1 day/week- but less than 4 days/week

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: High Sodium; Consumption of an extra 3900 mg of dietary sodium per day.	Dietary supplement: High Sodium; 10 days of 3900 mg of sodium/day in excess of normal dietary intake delivered via enteric capsules filled with table salt.
Placebo Comparator: Placebo; Control Condition	Other: Placebo; 10 days of enteric capsules filled with dextrose.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Reflected Pulse Wave Amplitude	Aortic pressure-flow relations will be assessed non-invasively using echocardiography and peripheral artery applanation tonometry. Wave separation analysis will be used to calculate reflected pulse wave amplitude.	On the 10th day of each arm.
Conduit artery endothelium-dependent dilation	Brachial artery flow mediated dilation (FMD) will be assessed by duplex ultrasound as an index of conduit artery endothelial function.	On the 10th day of each arm.
Arterial Stiffness	Carotid-femoral pulse wave velocity (cf-PWV) will be assessed via applanation tonometry as an index of aortic stiffness. cf-PWV will be calculated as the difference in timing of of pulse waves at the carotid and femoral arteries divided by the distance between measurements.	On the 10th day of each arm.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Wave reflection timing	Aortic pressure-flow relations will be assessed non-invasively using echocardiography and peripheral artery applanation tonometry. Wave separation analysis will be used to calculate reflected wave transit time.	On the 10th day of each arm.
Forward Pulse Wave Amplitude	Aortic pressure-flow relations will be assessed non-invasively using echocardiography and peripheral artery applanation tonometry. Wave separation analysis will be used to the amplitude of the forward traveling pulse wave.	On the 10th day of each arm.
24 Hour Blood Pressure	24 hour blood pressure monitoring will be performed using an ambulatory blood pressure monitor device. Average day and nighttime systolic, diastolic, and mean blood pressures will be determined.	The morning of day 9 through the morning of day 10 for each arm.

Collaborators and Investigators

• Sponsor: University of Delaware
• Investigators: Principal Investigator: David G Edwards, PhD, University of Delaware

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2020
• Primary Completion (Estimated): June 30, 2024
• Study Completion (Estimated): December 31, 2024

Study Registration Dates

• First Submitted: December 23, 2019
• First Submitted That Met QC Criteria: January 16, 2020
• First Posted (Actual): January 18, 2020

Study Record Updates

• Last Update Posted (Actual): November 29, 2023
• Last Update Submitted That Met QC Criteria: November 28, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Keywords: physical activity; oxidative stress; endothelium; ventricular-vascular coupling; pulsatile load
• Additional Relevant MeSH Terms: Metabolic Diseases; Water-Electrolyte Imbalance; Hypernatremia
• Other Study ID Numbers: 1452626

Drug and device information, study documents

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