Sodium Diet Effect on Aldosterone and Urinary RNA (SALTY) (SALTY)

This cross-over clinical trial is being conducted to evaluate the difference in urinary messenger RNA (mRNA) biomarkers of mineralocorticoid receptor activation following a low-sodium diet, as compared to a high-sodium diet. The study team will collect urine and blood samples from each participant to study mineralocorticoid receptor-regulated mRNA biomarkers following the consumption of each diet.

The study team will instruct the participants to consume 8 days each of high- (300 mmol/day) and low- (10 mmol/day) sodium meals. The order in which the participants will eat the two study diets will be randomly determined. In between the high- and low-sodium diets, the participants will have a wash-out period of 6 days, during which they will be encouraged to consume their usual diet. Participants will be asked to provide the study team with 24-hour urine samples, random urine samples, and blood samples throughout their participation in this clinical trial.

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Other: High-sodium diet 300 mmol sodium/day; Other: Low-sodium diet 10 mmol sodium/day

• Study Type: Interventional
• Enrollment (Actual): 21
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Michigan
    • Ann Arbor, Michigan, United States, 48109
      • University of Michigan

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 19 years to 48 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Normotensive, as defined by:

  • Systolic blood pressure (SBP) < 140 mmHg and diastolic blood pressure (DBP) < 90 mmHg
  • Never prescribed an antihypertensive medication
• Willingness to refrain from intense exercise (for example, swimming, biking, running)

Exclusion Criteria:

• Hypertension (history of blood pressure ≥ 140/90 mmHg)
• History of hypertensive urgency, hypertensive crisis, or hospitalizations for hypertension
• History of chronic kidney disease
• History of heart failure
• Current food allergy
• Pregnancy
• Known hyperaldosteronism
• Current mineralocorticoid antagonist use
• Current treatment for diabetes mellitus
• Known adrenal insufficiency
• Current glucocorticoid use
• Electrolyte abnormality on baseline laboratory assessment
• Current potassium supplementation
• Urinary tract infection (UTI)
• Significant renal insufficiency or any other condition thought by the Principal Investigator to place the participant at increased risk of injury during the clinical trial or compromise the scientific integrity of the study

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: High sodium diet	Other: High-sodium diet 300 mmol sodium/day; Day 7 or day 21 high-sodium diet begins for 8 days. Day 15 wash-out begins for 6 days. Pre-made meals for both the high-and low-sodium diet will be provided to each participant by the study team.
Experimental: Low sodium diet	Other: Low-sodium diet 10 mmol sodium/day; Day 7 or day 21 low-sodium diet begins for 8 days. Day 15 wash-out begins for 6 days. Pre-made meals for both the high-and low-sodium diet will be provided to each participant by the study team.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Urinary mineralocorticoid receptor-regulated messenger RNA (mRNA) biomarker	Urinary mRNA biomarkers following consumption of a high-sodium and low-sodium diet will be measured using real-time quantitative polymerase chain reaction (RT-qPCR).	Day 15 (after first diet period)
Urinary mineralocorticoid receptor-regulated mRNA biomarker	Urinary mRNA biomarkers following consumption of a high-sodium and low-sodium diet will be measured using real-time quantitative polymerase chain reaction (RT-qPCR).	Day 29 (after second diet period)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood pressure	Systolic and diastolic blood pressure measurement following consumption of a high-sodium compared to a low-sodium diet	Day 15 (after first diet period)
Blood pressure	Systolic and diastolic blood pressure measurement following consumption of a high-sodium compared to a low-sodium diet	Day 29 (after second diet period)

Collaborators and Investigators

• Sponsor: University of Michigan
• Collaborators: National Heart, Lung, and Blood Institute (NHLBI)
• Investigators: Principal Investigator: J Brian Byrd, MD, MS, University of Michigan

Study record dates

Study Major Dates

• Study Start (Actual): February 12, 2020
• Primary Completion (Actual): December 8, 2021
• Study Completion (Actual): December 8, 2021

Study Registration Dates

• First Submitted: November 15, 2019
• First Submitted That Met QC Criteria: November 15, 2019
• First Posted (Actual): November 19, 2019

Study Record Updates

• Last Update Posted (Estimate): December 15, 2022
• Last Update Submitted That Met QC Criteria: December 6, 2022
• Last Verified: December 1, 2022

More Information

Terms related to this study

• Keywords: biomarker; aldosterone; low sodium diet; high sodium diet; mineralocorticoid; mineralocorticoid receptor
• Other Study ID Numbers: HUM00097366; 1K23HL128909-01A1 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

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

IPD Plan Description

We will de-identify participant information and will share it with a trusted repository, such as National Institutes of Health (NIH) Figshare or The Inter-university Consortium for Political and Social Research (ICPSR).

We will de-identify and share data obtained from analyzing urinary mRNA biomarkers and measuring the systolic and diastolic blood pressure following consumption of a high-sodium and low-sodium diet. Additionally, specific lab values that support the validity and quality of the study treatment will be shared in a trusted repository.

• IPD Sharing Time Frame: De-identified data will be deposited into a repository within 1 year of the conclusion of the study.
• IPD Sharing Access Criteria: No additional access restrictions will be placed on the de-identified data, beyond those required by the repository to access or download the data.
• IPD Sharing Supporting Information Type: Study Protocol; Informed Consent Form (ICF)

Drug and device information, study documents

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