Hypertension
Conditions
Keywords
Blood pressure, Sodium, Salt, Randomized controlled trial, balance, humans
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.
Interventions
OTHERHigh dietary sodium intake
Fourteen day feeding period of high dietary sodium (3400 mg/day)
OTHERLow dietary sodium intake
Fourteen day feeding period of low dietary sodium (2300 mg/day)
Sponsors
University of California, San Diego
Study design
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.
Intervention model description
Dietary intervention consisting of two 25-day feeding periods separated by a 10-day washout.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
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; * Smoker; * Serious food allergies; * Currently pregnant or planning to become pregnant
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Estimated sodium concentration in skin and muscle | 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). |
| Estimated sodium concentration in bone | 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 | 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. |
| Blood pressure | 60 days | Blood pressure under high versus low dietary sodium conditions will be measured. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Racial differences in concentrations of sodium in skin, muscle and bone | 60 days | Blacks/African Americans mean sodium concentrations versus the average of the means of each of the other racial/ethnic groups will be examined. |
| Racial differences in concentration of urinary potassium excretion | 60 days | The concentration of potassium excreted in urine will be compared between Blacks/African Americans versus the pooled sample of other racial/ethnic groups. |
Countries
United States
Outcome results
None listed