Effects of Acute Dietary Sodium on Cerebrovascular Reactivity and Blood Pressure Reactivity

Americans eat more salt than is recommended by the American Heart Association. This is important because consuming a high-salt diet is associated with an increased risk of cardiovascular events, like strokes and heart attacks. In fact, consuming one high-salt meal temporarily reduces blood vessel function and it is not uncommon for Americans to consume high-salt meals. Therefore, our laboratory is interested in determining if a single high-salt meal affects 1) brain blood vessel function at rest and 2) blood pressure responses during exercise.

Study Overview

• Status: Completed
• Conditions: Blood Pressure; Cerebrovascular Reactivity
• Intervention / Treatment: Other: Low Sodium Meal (138 mg sodium); Other: High Sodium Meal (1,495 mg sodium)

Detailed Description

Excess dietary salt increases the risk of cardiovascular events like strokes and heart attacks, independent of resting blood pressure. Recent data found that consuming one high-salt meal temporarily reduces endothelial function in the periphery. This decrease in endothelial function can lead to an exaggerated blood pressure response during exercise and may also attenuate cerebrovascular reactivity at rest. This is essential, because an exaggerated cardiovascular response to exercise and a decrease in brain blood vessel function at rest are risk factors for future cardiovascular events. The long-term goal is to determine how dietary salt adversely affects BP and cerebrovascular regulation. The objective of this proposal is to evaluate the impact of an acute dietary salt meal on BP response during exercise and cerebrovascular reactivity at rest. The investigators have 2 specific aims: 1) Aim 1 will test the hypothesis that high dietary salt will reduce cerebrovascular reactivity, 2) Aim 2 will test the hypothesis that high dietary salt will augment blood pressure reactivity during exercise. The findings of this project will shed light on how acute dietary salt affects the risk of cardiovascular events during a bout of exercise and long-term risk for cardiovascular disease and stroke.

• Study Type: Interventional
• Enrollment (Actual): 37
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Delaware
    • Newark, Delaware, United States, 19713
      • William B Farquhar

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• normal blood pressure
• males, females, minorities

Exclusion Criteria:

• high blood pressure
• body mass index (BMI > 30 kg/m2)
• smokers or nicotine users
• those who are pregnant or planning to become pregnant
• allergy to the tomato soup

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Cerebrovascular Reactivity; Cerebrovascular reactivity (CVR) will be assessed using transcranial Doppler ultrasound with carbon dioxide as the vasoactive stimuli. The intervention is to provide subjects with either a low sodium meal (138 mg sodium) and high sodium meal (1,495 mg sodium), in a randomized order. The CVR test will be performed prior to soup consumption as well as after soup consumption.	Other: Low Sodium Meal (138 mg sodium); One Low Sodium Meal; Other: High Sodium Meal (1,495 mg sodium); One High Sodium Meal
Experimental: Blood Pressure Reactivity; Blood pressure responses during dynamic exercise will be assessed. The intervention is to provide subjects with either a low sodium meal (138 mg sodium) and high sodium meal (1,495 mg sodium), in a randomized order. Blood pressure reactivity during dynamic exercise will be assessed after soup consumption.	Other: Low Sodium Meal (138 mg sodium); One Low Sodium Meal; Other: High Sodium Meal (1,495 mg sodium); One High Sodium Meal

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from Baseline Cerebrovascular Reactivity post soup consumption	Middle Cerebral Artery/ End-tidal Carbon Dioxide (cm/s/mmHg)	Prior to and 60 minutes after soup consumption
Blood Pressure Reactivity- Dynamic Exercise	Change in Blood Pressure during dynamic exercise (mmHg)	80 minutes after soup consumption

Collaborators and Investigators

• Sponsor: University of Delaware
• Investigators: Principal Investigator: William B Farquhar, PhD, University of Delaware; Principal Investigator: Kamila U Migdal, BS, University of Delaware

Publications and helpful links

General Publications

• Migdal KU, Robinson AT, Watso JC, Babcock MC, Serrador JM, Farquhar WB. A high-salt meal does not augment blood pressure responses during maximal exercise. Appl Physiol Nutr Metab. 2020 Feb;45(2):123-128. doi: 10.1139/apnm-2019-0217. Epub 2019 Jun 25.

Study record dates

Study Major Dates

• Study Start (Actual): May 1, 2018
• Primary Completion (Actual): June 1, 2020
• Study Completion (Actual): June 1, 2020

Study Registration Dates

• First Submitted: May 16, 2018
• First Submitted That Met QC Criteria: June 8, 2018
• First Posted (Actual): June 20, 2018

Study Record Updates

• Last Update Posted (Actual): September 22, 2020
• Last Update Submitted That Met QC Criteria: September 18, 2020
• Last Verified: September 1, 2020

More Information

Terms related to this study

• Other Study ID Numbers: 1178955-1

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