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

NCT04717336 | Completed Results

• 2 other identifiers: 10000070000070-H
• Study Type: interventional
• Target: 36
• Locations: 1 country
• Sites: 1

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.

Conditions

Cardiovascular Disease

Keywords

African American; Cardiovascular Disease

Outcome Measures

Primary Outcomes (1)

• Mean Change in Vascular Function Measured by Pulse Wave Velocity

  Mean change in vascular function was measured by Pulse Wave Velocity (PWV) using the SphygmoCor XCEL. PWV was determined by recording the pulse waves of the carotid and femoral arteries and calculating the ratio of the distance between the pulse measuring sites to the time delay between the carotid and femoral pulse waves. The distance was measured with a non-stretchable tape from the suprasternal notch to the carotid site and from the suprasternal notch to the femoral site. The former distance was subtracted from the latter and used in the calculation of PWV. High PWV is directly associated with increased arterial stiffness, reflecting reduced elasticity of the arterial walls.

  Baseline, Week 2, Week 5 and Week 7

Study Arms (2)

Cohort 1: Sodium Chloride then Placebo

EXPERIMENTAL

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.

Other: Sodium Chloride; Other: Placebo

Cohort 2: Placebo then Sodium Chloride

EXPERIMENTAL

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.

Other: Sodium Chloride; Other: Placebo

Interventions

Sodium Chloride 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.

Also known as: salt treatment

Cohort 1: Sodium Chloride then Placebo; Cohort 2: Placebo then Sodium Chloride

Placebo OTHER

placebo capsules

Cohort 1: Sodium Chloride then Placebo; Cohort 2: Placebo then Sodium Chloride

Eligibility Criteria

• Age: 21 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• National Heart, Lung, and Blood Institute (NHLBI): lead
• National Human Genome Research Institute (NHGRI): collaborator

Study Sites (1)

National Institutes of Health Clinical Center

Bethesda, Maryland, 20892, United States

Location

Related Links

• NIH Clinical Center Detailed Web Page

MeSH Terms

Conditions

Cardiovascular Diseases

Interventions

Sodium Chloride

Intervention Hierarchy (Ancestors)

Chlorides; Hydrochloric Acid; Chlorine Compounds; Inorganic Chemicals; Sodium Compounds

Results Point of Contact

• Title: Georg Aue, MD
• Organization: The National Heart, Lung, and Blood Institute (NHLBI) at the National Institutes of Health (NIH)

aueg@nhlbi.nih.gov

301.451.7141

Study Officials

• Amadou Gaye, PhD

  National Human Genome Research Institute (NHGRI)

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: NIH
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 20, 2021
• First Posted: January 22, 2021
• Study Start: January 22, 2021
• Primary Completion: June 30, 2022
• Study Completion: July 8, 2022
• Last Updated: April 27, 2025
• Results First Posted: April 27, 2025

Record last verified: 2024-07-23

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)