Sodium Regulation in Individuals on Known Dietary Sodium Intake
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Enrollment
- 52
- Locations
- 1
- Primary Endpoint
- Blood pressure
Study Overview
Brief Summary
The overall objective of this study is to examine how dietary sodium is used by the body. In a racially diverse sample of adults, the investigators will examine the effects of high and low dietary sodium intake on the storage and excretion of sodium and determine whether sodium distribution affects blood pressure. This has implications for how investigators interpret studies that use urine biomarkers of sodium. Study findings about tissue sodium storage also have implications for managing hypertension and related conditions.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover
- Primary Purpose
- Basic Science
- Masking
- Single (Outcomes Assessor)
Masking Description
Throughout data collection, study data collectors and the study coordinator will remain blinded to participants' exposure group.
Eligibility Criteria
- Ages
- 18 Years to — (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •At least 18 years old;
- •Diagnosed with high blood pressure or pre-hypertension (systolic blood pressure (SBP) > 120 mm Hg or diastolic blood pressure (DBP) > 80 mm Hg);
- •Taking no more than two medications for high blood pressure;
- •Currently has a primary care provider;
- •Willing to eat all meals provided by the study for two 14-day feeding periods;
- •Willing to complete study measurement procedures.
Exclusion Criteria
- •Diabetes;
- •Serious food allergies;
- •Currently pregnant or planning to become pregnant
Arms & Interventions
High-low dietary sodium
High sodium diet (3400 mg/day) feeding period followed by low sodium diet (2300 mg/day) feeding period
Intervention: High dietary sodium intake (Other)
High-low dietary sodium
High sodium diet (3400 mg/day) feeding period followed by low sodium diet (2300 mg/day) feeding period
Intervention: Low dietary sodium intake (Other)
Low-high dietary sodium
Low sodium diet (2300 mg/day) feeding period followed by high sodium diet (3400 mg/day) feeding period
Intervention: High dietary sodium intake (Other)
Low-high dietary sodium
Low sodium diet (2300 mg/day) feeding period followed by high sodium diet (3400 mg/day) feeding period
Intervention: Low dietary sodium intake (Other)
Outcomes
Primary Outcomes
Blood pressure
Time Frame: 60 days
Blood pressure under high versus low dietary sodium conditions will be measured.
Estimated sodium concentration in bone
Time Frame: 60 days
The concentration of sodium in bone will be measured, and the difference in concentrations resulting from high versus low sodium intakes will be calculated. Sodium storage in bone will be measured non-invasively using in vivo neutron activation analysis (IVNAA) technology to quantify the concentration of Na in the hand.
Concentration of sodium, potassium, and hormone regulators in excreted urine
Time Frame: 60 days
Urinary concentration of sodium, potassium, and hormones (renin, angiotensin, aldosterone, free cortisol, free cortisone, glucocorticoid, and mineralocorticoid) will be measured and variation over time will be calculated.
Estimated sodium concentration in skin and muscle
Time Frame: 60 days
The concentration of sodium in skin and muscle will be measured, and the difference in concentrations resulting from high versus low sodium intakes will be calculated. Skin and muscle sodium stores will be non-invasively quantified using 23sodium-magnetic resonance imaging (23Na-MRI).
Secondary Outcomes
- Racial differences in concentrations of sodium in skin, muscle and bone(60 days)
- Racial differences in concentration of urinary potassium excretion(60 days)
Investigators
Cheryl Anderson
Professor / Dean
University of California, San Diego