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

Early Phase 1

Completed

Conditions: Cardiovascular Disease

Interventions: Other: SODIUM CHLORIDE
Other: placebo

Registration Number: NCT04717336

Lead Sponsor: National Human Genome Research Institute (NHGRI)

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.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 36

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
PERIOD 1: Sodium Chloride then Placebo	SODIUM CHLORIDE	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.
PERIOD 1: Sodium Chloride then Placebo	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.
PERIOD 2: Placebo then Sodium Chloride	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.
PERIOD 2: Placebo then Sodium Chloride	placebo	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.

Primary Outcome Measures

Name	Time	Method
Mean Change in Vascular Function Measured by Pulse Wave Velocity	Baseline, Week 2, Week 5 and Week 7	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.

Secondary Outcome Measures