Skip to content

Analyzing Genetic Factors Involved in Blood Pressure Changes Due to Salt and Potassium Intake (The GenSalt Study)

Genetic Epidemiology Network of Salt Sensitivity

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00721721
Acronym
GenSalt
Enrollment
1906
Registered
2008-07-24
Start date
2003-10-31
Completion date
2009-05-31
Last updated
2016-07-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Blood Pressure

Keywords

Dietary Sodium, Dietary Potassium, Genes, Genomics

Brief summary

High blood pressure is a serious health problem. In terms of diet recommendations, people with this condition are encouraged to eat a low sodium and high potassium diet. It is believed that genetics may play a role in the development of high blood pressure and may affect changes in blood pressure levels, including changes brought on by sodium and potassium. This study will identify genetic factors that may influence blood pressure changes due to increased salt or potassium intake in people with mildly elevated blood pressure and in their family members.

Detailed description

High blood pressure is one of the most common health problems among adults. If left untreated, it can lead to heart failure, kidney failure, or stroke. Common causes include stress, diet, diabetes, kidney disease, or obesity. Typical treatments include taking medication, losing weight, and quitting smoking. It is also recommended that people with high blood pressure or those at risk of developing high blood pressure modify their diets to decrease sodium intake and increase potassium intake. Research has shown that genetics may play a role in the development of high blood pressure and may affect fluctuations of blood pressure levels, including blood pressure changes brought on by sodium and potassium. This study will identify and analyze the genetic factors that may be responsible for blood pressure changes due to dietary salt and potassium intake. Blood samples collected in this study may also be used for future genetic research on blood pressure. This study will enroll people who have mildly elevated blood pressure and their siblings, spouses, and children. Participants will first take part in a 3-day observation period. At a Day 1 study visit, participants' weight, height, waist size, and blood pressure will be measured. There will be three separate blood pressure measurements. Study staff will then interview participants to collect information on family and personal medical history, cigarette smoking habits, alcohol consumption, physical activity, and diet. Finally, blood samples will be collected. For 24 hours after the first study visit, participants will collect their urine. At study visits on Days 2 and 3, participants will undergo three blood pressure measurements and a cold pressor test, which measures blood pressure at different body temperatures. Participants will also collect a urine sample each night. After the 3-day observation period, participants will take part in a 3-week treatment period. Each day, all participants will eat breakfast, lunch, and dinner in the study kitchen. For Days 1 through 7, participants will eat a low sodium diet; for Days 7 through 14, participants will eat a high sodium diet; and for Days 14 through 21, participants will eat a high sodium diet and receive potassium supplements. Blood pressure will be measured three times per day and urine will be collected at several times during this period. Blood samples will be collected at the end of each week. Parents of participants will also be enrolled in this study, and they will complete the same study procedures that participants complete during the 3-day observation period except for the urine collection. The study completion date listed in this record was obtained from the Completed Date entered in the Query View Report System (QVR).

Interventions

BEHAVIORALLow Sodium Diet

3 grams of salt or 51.3 mmol of sodium per day

18 grams of salt or 307.8 mmol of sodium per day

DIETARY_SUPPLEMENTPotassium Supplementation

60 mmol potassium supplement

Sponsors

National Heart, Lung, and Blood Institute (NHLBI)
Lead SponsorNIH

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
No

Inclusion criteria

Inclusion Criteria for Primary Participants: * Between 18 and 60 years old * Systolic blood pressure level of 130 to 160 mm Hg and/or diastolic blood pressure level of 85 to 100 mm Hg * Both parents (2-generation nuclear family) or at least one parent (at least a 3-generation family) is available and willing to participate in the study * At least one sibling meets eligibility criteria for participation Inclusion Criteria for Sibling/Spouse/Child Participants: * Siblings and spouses must be between 18 and 60 years old; children must be more than 16 years old * Lives in the same village as the main study participant

Exclusion criteria

for All Participants: * Current stage 2 hypertension (systolic blood pressure level greater than or equal to 160 mm Hg and/or diastolic blood pressure level greater than or equal to 100 mm Hg) * Current or recent (i.e., less than 1 month before the screening visit) use of antihypertensive medications or medications that affect blood pressure * Secondary hypertension * History of clinical cardiovascular disease, including heart attack, congestive heart failure, stroke, and peripheral arterial disease * Chronic kidney failure or urinary albumin concentration of greater than or equal to 20 mg/dL * Current diabetes (i.e., fasting serum glucose level greater than or equal to 126 mg/dL) or use of insulin or oral hypoglycemic agents * Peptic ulcer disease requiring treatment in the 2 years before study entry * Liver disease requiring treatment in the 2 years before study entry * Pregnant * Heavy alcohol drinker (i.e., more than 14 drinks per week) * Currently adhering to a low sodium diet

Design outcomes

Primary

MeasureTime frame
Blood pressureMeasured at Day 21

Countries

China

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Apr 3, 2026