Vascular Effects of Dietary Salt in Humans With Salt-Resistant Blood Pressure

Vascular Effects of Dietary Salt in Humans With Salt-Resistant Blood Pressure: Dietary Counseling Study

The purpose of this study is to determine the effects of dietary salt restriction on central hemodynamics and vascular function in men and women with salt resistant blood pressure.

Study Overview

• Status: Recruiting
• Conditions: Healthy
• Intervention / Treatment: Other: Dietary Sodium Restriction; Other: Control

Detailed Description

Cardiovascular disease remains a major Public Health problem and is the leading cause of death in the US. Dietary sodium restriction is considered an important lifestyle modification for individuals with hypertension; however, there is controversy about the effects of dietary salt given that many individuals do not have "salt sensitive" blood pressure. Deleterious effects of salt on the vasculature may explain the finding that chronic DSR reduces the cardiovascular event rate by 25%despite only minor reductions in BP. It is not known whether dietary sodium restriction improves central pulsatile hemodynamics, known to be related to the development of left ventricular hypertrophy and heart failure risk, and whether the hypothesized improvements in central hemodynamics are similar in men & women. The purpose of this study is to determine the effects of dietary sodium restriction through dietary counseling on central hemodynamics and vascular function in men and women with salt resistant blood pressure.

• Study Type: Interventional
• Enrollment (Estimated): 125
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: William B Farquhar, PhD; Phone Number: 302-831-6178; Email: wbf@udel.edu
• Study Contact Backup: Name: David G Edwards, PhD; Phone Number: 302-831-3363; Email: dge@udel.edu

Study Locations

• United States
  • Delaware
    • Newark, Delaware, United States, 19713
      • Recruiting
      • Department of Kinesiology and Applied Physiology, University of Delaware
      • Contact: William B Farquhar, PhD; Phone Number: 302-831-6178; Email: wbf@udel.edu
      • Contact: David G Edwards, PhD; Phone Number: 302-831-3363; Email: dge@udel.edu
      • Principal Investigator: David G Edwards, PhD
      • Principal Investigator: William B Farquhar, PhD
      • Principal Investigator: Shannon Lennon, PhD

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Habitual dietary sodium intake > 3400mg per day

Exclusion Criteria:

• Abnormal resting ECG
• Current abnormal blood panel (assessed by comprehensive metabolic panel, lipid panel and complete blood count).
• Hypertension (currently taking anti-hypertensive medications or resting blood pressure >140/90 mmHg)
• Medical history of cardiovascular disease, malignant cancer, diabetes or kidney disease
• Obesity (Body Mass Index > 30)
• Current pregnancy
• Unable to provide consent

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Dietary Sodium Restriction; Daily habitual dietary sodium intake < 2000mg	Other: Dietary Sodium Restriction; A registered dietician will counsel participants to reduce daily habitual dietary salt intake below 2000mg over 4 weeks
Sham Comparator: Control; Routine habitual dietary sodium intake >3400mg	Other: Control; Participants will consume their routine habitual dietary sodium intake > 3400mg per day with regular pre determined check in phone calls from a registered dietician.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Reflected Pulse Wave Amplitude	Late systolic pulsatile load on the left ventricle represented by reflected pulse wave amplitude; assessed by echocardiography combined with applanation tonometry.	Change from baseline at 4 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Microvascular Function	Cutaneous microvascular dilatory response to local heating assessed by laser Doppler flowmetry coupled with intradermal microdialysis	Change from baseline at 4 weeks
Conduit Artery Endothelial Dependent Dilation	Brachial artery flow mediated dilation assessed by duplex ultrasound	Change from baseline at 4 weeks
Arterial Stiffness	Carotid - Femoral pulse wave velocity assessed by applanation tonometry	Change from baseline at 4 weeks
Forward pulse wave amplitude	Central hemodynamic assessment of the forward pulse wave amplitude assessed by echocardiography combined with applanation tonometry.	Change from baseline at 4 weeks

Collaborators and Investigators

• Sponsor: University of Delaware
• Investigators: Principal Investigator: William B Farquhar, PhD, University of Delaware; Principal Investigator: David G Edwards, PhD, University of Delaware; Principal Investigator: Shannon Lennon, PhD, University of Delaware

Study record dates

Study Major Dates

• Study Start (Actual): January 21, 2018
• Primary Completion (Estimated): March 1, 2024
• Study Completion (Estimated): March 1, 2024

Study Registration Dates

• First Submitted: January 29, 2018
• First Submitted That Met QC Criteria: February 5, 2018
• First Posted (Actual): February 7, 2018

Study Record Updates

• Last Update Posted (Actual): November 28, 2023
• Last Update Submitted That Met QC Criteria: November 27, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Keywords: Cardiovascular Disease; Oxidative Stress; Hemodynamics; Dietary Sodium; Endothelium, vascular; Dietary Counseling
• Other Study ID Numbers: 1083986

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