CARDIA-Salt Sensitivity of Blood Pressure (SSBP)
Keywords
Abstract
Dates
Last Verified: | 06/30/2020 |
First Submitted: | 02/03/2020 |
Estimated Enrollment Submitted: | 02/03/2020 |
First Posted: | 02/05/2020 |
Last Update Submitted: | 07/06/2020 |
Last Update Posted: | 07/08/2020 |
Actual Study Start Date: | 09/30/2020 |
Estimated Primary Completion Date: | 08/30/2024 |
Estimated Study Completion Date: | 08/30/2024 |
Condition or disease
Intervention/treatment
Dietary Supplement: High Salt Diet
Dietary Supplement: Low Salt Diet
Phase
Arm Groups
Arm | Intervention/treatment |
---|---|
Other: High Salt Diet then Low Salt Diet The high-salt diet will be achieved through the supplementation of each participant's usual diet with Na+ bullion packets (2 packets per day). This will increase Na+ intake by approximately 2,200 mg (≈100 mEq Na+) to a total greater than 5,000 mg Na+ per day based on prior estimates of Na+ intake (see section C1.2). In addition, 1,000 mg of calcium carbonate (provided via Tums tablets) will be taken daily on the high Na+ diet to reduce the potential impact of changes in calcium intake on blood pressure.
The low-salt diet is comprised of 7 days of freshly prepared frozen meals, snacks, and Na+ free water. All low-salt meals will be prepared in each site's Metabolic Kitchen, with standardization of diets across sites. The low-salt diet includes: 20 mEq Na+ (±2 mEq) (460 mg/day), 100 mEq potassium (±2 mEq), and 1,000 mg calcium (±50 mg). | |
Other: Low Salt Diet then High Salt Diet The low-salt diet is comprised of 7 days of freshly prepared frozen meals, snacks, and Na+ free water. All low-salt meals will be prepared in each site's Metabolic Kitchen, with standardization of diets across sites. The low-salt diet includes: 20 mEq Na+ (±2 mEq) (460 mg/day), 100 mEq potassium (±2 mEq), and 1,000 mg calcium (±50 mg).
The high-salt diet will be achieved through the supplementation of each participant's usual diet with Na+ bullion packets (2 packets per day). This will increase Na+ intake by approximately 2,200 mg (≈100 mEq Na+) to a total greater than 5,000 mg Na+ per day based on prior estimates of Na+ intake (see section C1.2). In addition, 1,000 mg of calcium carbonate (provided via Tums tablets) will be taken daily on the high Na+ diet to reduce the potential impact of changes in calcium intake on blood pressure. |
Eligibility Criteria
Ages Eligible for Study | 50 Years To 50 Years |
Sexes Eligible for Study | All |
Accepts Healthy Volunteers | Yes |
Criteria | Inclusion Criteria: Potentially eligible individuals must consent to and be willing to adhere to the study protocol. We will include individuals not taking anti-HTN medications, i.e. normotensives and untreated hypertensives, and individuals with controlled HTN by use of ≤ 3 anti-HTN medications. Exclusion Criteria: - Unwilling to adhere to the study protocol - Resistant HTN, defined as taking ≥ 4 anti-HTN medications to control BP or uncontrolled BP despite ≥ 3 anti-HTN medications that includes a diuretic - Contraindications to high- or low-salt diet (e.g. heart, renal, or liver failure, postural orthostatic tachycardia syndrome) - Use of salt tabs, fludricortisone, midodrine - Contraindications to 24hr ABPM: bilateral upper extremity lymphedema, cuff will not fit - Medical contraindications to foods, e.g. celiac disease, nut allergy, egg allergy, etc. - Year 35 core exam systolic BP < 90 or > 160 mm Hg or diastolic BP < 50 or > 100 mm Hg - Current use of steroids, NSAIDS, anti-inflammatories - Rheumatologic condition (e.g. Lupus, Rheumatoid Arthritis, Psoriatic arthritis, Inflammatory Bowel Disease, Multiple Sclerosis - Immune deficiency or immunosuppressed |
Outcome
Primary Outcome Measures
1. Salt sensitivity of blood pressure [14 days]
2. Immune response to dietary salt loading, IL-6 [14 days]
3. Immune response to dietary salt loading, Change in circulating levels of IL-17 [14 days]
4. Immune response to dietary salt loading, IL-10 [14 days]