Genomics, Environmental Factors and Social Determinants of Cardiovascular Disease in African Americans Study (GENE-FORECAST): Sodium Intervention Trial (SIT)

NCT ID: NCT04717336

Last Updated: 2025-04-27

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 36 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2021-01-22
• Study Completion Date: 2022-07-08

Brief Summary

Background:

Hypertension is a risk factor for heart disease. Low-sodium diets rich in fruits, vegetables, and other healthy foods are a good way to reduce blood pressure in people with hypertension. Researchers want to learn more about why African Americans seem to have the greatest benefit from certain dietary interventions.

Objective:

To better understand the body's response to adding more salt to the diet.

Eligibility:

U.S.-born African American adults ages 21 to 65 who are in good general health and took part in the GENE-FORECAST.

Design:

Participants will be screened with a medical history and physical exam. If needed, they will take a pregnancy test. These tests will be repeated during the study.

Each day for 2 weeks, participants will take 3 capsules that contain either placebo or salt. Then they will take no pills for 3 weeks. Then they will take placebo or salt capsules for 2 more weeks.

Participants will talk about the foods and drinks they have consumed over the past 24 hours. They will take a survey about their physical activity and sleep.

Participants will complete taste tasks to obtain their responses to sweetness or saltiness. Sucrose and salt detection thresholds and preferences will be assessed.

Participants will give blood and urine samples. Saliva samples will be collected from their mouth by passive drool or by spitting into a sterile tube. Skin samples will be collected from behind their ears and the inner part of their elbow, using sterile swabs. Participants will get kits to collect stool samples at home.

Participants will have 4 study visits over 7 weeks.

Detailed Description

The objective of this study is to implement a sodium intervention investigation to assess the effect of increased dietary sodium intake on changes in blood pressure, vascular function, microbiome, whole blood epigenome, whole blood and urine transcriptome as outcome measures. The study design will include a double-blind, cross-over treatment/placebo trial among African Americans GENE-FORECAST participants with normal blood pressure and will last 7 weeks. It is hypothesized that exposure to increased dietary sodium will affect blood pressure, whole blood epigenome, whole blood and urine transcriptome, vascular function, microbiome and blood pressure.

Conditions

Cardiovascular Disease

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: TRIPLE

Study Groups

Cohort 1: Sodium Chloride then Placebo

Participant will take Sodium Chloride at 3 pills per day for a total of 3 grams for two weeks, followed by a wash-out period for three-weeks, then ending with a cross-over to the Placebo at 3 pills per day for a total of 3 grams for two weeks.

Group Type: EXPERIMENTAL

Sodium Chloride

Intervention Type: OTHER

It is well established that increased dietary sodium can predispose to an increase in blood pressure; particularly in salt-sensitive individuals. Seeking to test the hypothesis that changes in dietary sodium intake are sufficient to influence the composition of the gut microbiome in association with sodium-induced changes in vascular function, epigenome, transcriptome and blood pressure in African Americans.

Placebo

Intervention Type: OTHER

placebo capsules

Cohort 2: Placebo then Sodium Chloride

Participant will take Placebo at 3 pills per day for a total of 3 grams for two weeks, followed by a wash-out period for three-weeks, then ending with a cross-over to the Sodium Chloride at 3 pills per day for a total of 3 grams for two weeks.

Group Type: EXPERIMENTAL

Sodium Chloride

Intervention Type: OTHER

It is well established that increased dietary sodium can predispose to an increase in blood pressure; particularly in salt-sensitive individuals. Seeking to test the hypothesis that changes in dietary sodium intake are sufficient to influence the composition of the gut microbiome in association with sodium-induced changes in vascular function, epigenome, transcriptome and blood pressure in African Americans.

Placebo

Intervention Type: OTHER

placebo capsules

Interventions

Sodium Chloride

It is well established that increased dietary sodium can predispose to an increase in blood pressure; particularly in salt-sensitive individuals. Seeking to test the hypothesis that changes in dietary sodium intake are sufficient to influence the composition of the gut microbiome in association with sodium-induced changes in vascular function, epigenome, transcriptome and blood pressure in African Americans.

Intervention Type: OTHER

Placebo

placebo capsules

Intervention Type: OTHER

Other Intervention Names

salt treatment

Eligibility Criteria

Inclusion Criteria

African American men and women who are former GENE-FORECAST participants between 21 and 65 years of age. This criterion is inclusive of self-identified AA of both Hispanic, Latino and non-Hispanic, Latino ethnicities. Normotensive participants with systolic blood pressure (SBP) <140 mm Hg and diastolic blood pressure (DBP) <90 mm Hg and the absence of a history of prior diagnosis of hypertension.

-Willingness and ability to participate in study procedures.

Exclusion Criteria

• Individuals who are pregnant or breast-feeding.
• Individuals with high blood pressure or a history of hypertension.
• Individuals with a history of myocardial infarction, stroke, heart failure, diabetes, chronic liver or kidney diseases.
• Individuals who are taking antihypertensive, antidepressants, antidiabetic and antibiotic medications.
• Individuals currently participating in another NIH protocol.
• Individuals unable to provide informed consent.

• Minimum Eligible Age: 21 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

National Human Genome Research Institute (NHGRI)

NIH

Sponsor Role: collaborator

National Heart, Lung, and Blood Institute (NHLBI)

NIH

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Amadou Gaye, PhD

Role: PRINCIPAL_INVESTIGATOR

National Human Genome Research Institute (NHGRI)

Locations

National Institutes of Health Clinical Center

Bethesda, Maryland, United States

Countries

United States

Provided Documents

Document Type: Study Protocol and Statistical Analysis Plan

View Document

Document Type: Informed Consent Form

View Document

Related Links

https://clinicalstudies.info.nih.gov/cgi/detail.cgi?B_000070-HG.html

NIH Clinical Center Detailed Web Page

Other Identifiers

000070-H

Identifier Type: -

Identifier Source: secondary_id

10000070

Identifier Type: -

Identifier Source: org_study_id