Low vs High Sodium Diet for High Blood Pressure
Recruiting in Palo Alto (17 mi)
Age: 18+
Sex: Any
Travel: May Be Covered
Time Reimbursement: Varies
Trial Phase: Academic
Recruiting
Sponsor: Medical College of Wisconsin
Must not be taking: Glucocorticoids, Anticoagulants
Disqualifiers: Diabetes, Heart failure, Kidney disease, others
No Placebo Group
Trial Summary
What is the purpose of this trial?
Salt sensitive hypertension is a significant health problem worldwide and a primary modifiable risk factor for renal, cardiovascular, and cerebrovascular diseases. Yet, the underlying mechanisms remain poorly understood. The proposed study determines how renal oxygenation and substrate metabolism differs between individuals with and without salt sensitivity, with the ultimate goal of identifying mechanisms, diagnostic criteria, and treatment strategies for salt sensitive hypertension.
Will I have to stop taking my current medications?
The trial does not specify if you need to stop taking your current medications, but you cannot participate if you use glucocorticoids or anti-platelet and anticoagulant agents like aspirin.
What data supports the effectiveness of the treatment for high blood pressure?
Is a low or high sodium diet safe for humans?
Research suggests that reducing sodium intake can lower blood pressure, which is generally safe and beneficial for people with high blood pressure. However, there is limited evidence on the long-term safety of low sodium diets in terms of overall health outcomes like mortality and morbidity, and more studies are needed to confirm these effects.678910
How does the low vs high sodium diet treatment for high blood pressure differ from other treatments?
Eligibility Criteria
This trial is for English-speaking individuals with blood pressure levels indicating elevated BP or Stage 1 hypertension, as per the 2017 ACC/AHA guidelines. It's not suitable for those with normal or severe high blood pressure, diabetes, heart failure, liver cirrhosis, electrolyte issues, kidney disease, certain medication use (like glucocorticoids), pregnant/nursing women, bleeding disorders, heavy daily salt intake (>6000 mg/day), metallic implants presence in body including pacemakers.Inclusion Criteria
I speak English.
My blood pressure is high but not severe, according to the 2017 guidelines.
Exclusion Criteria
You are allergic to shellfish.
You are afraid of small, enclosed spaces.
I have a bleeding disorder.
See 10 more
Trial Timeline
Screening
Participants are screened for eligibility to participate in the trial
1 week
1 visit (in-person)
Low Sodium Diet
Participants follow a low sodium diet (1200 mg/day) for two weeks with food logs and dietary assessments
2 weeks
1 visit (in-person) for BOLD MRI and other assessments
Wash-out
Participants undergo a wash-out period between diet phases
1 week
High Sodium Diet
Participants follow a high sodium diet (>4200 mg/day) for two weeks with sodium chloride supplementation if needed
2 weeks
1 visit (in-person) for BOLD MRI and renal vein sampling for some participants
Follow-up
Participants are monitored for changes in renal oxygenation and metabolites after diet interventions
1 week
Treatment Details
Interventions
- high sodium diet (Behavioural Intervention)
- Low sodium diet (Behavioural Intervention)
Trial OverviewThe study investigates how a low sodium diet versus a high sodium diet affects kidney oxygenation and metabolism in people who are sensitive to salt. This could help understand why some individuals develop high blood pressure when they consume salt and lead to better diagnostic methods and treatments.
Participant Groups
2Treatment groups
Active Control
Group I: Low sodium dietActive Control1 Intervention
-Subjects will be randomized to start a low sodium diet (1200 mg/day) for two weeks (this will be followed by a high sodium diet - crossover design)
Group II: high sodium dietActive Control1 Intervention
-Subjects will be randomized to start a high sodium diet (4200 mg/day) for two weeks (this will be followed by a low sodium diet - crossover design)
Find a Clinic Near You
Research Locations NearbySelect from list below to view details:
Medical College of Wisconsin /Froedtert HospitalMilwaukee, WI
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Who Is Running the Clinical Trial?
Medical College of WisconsinLead Sponsor
References
Advice to reduce dietary salt for prevention of cardiovascular disease. [2018]Restricting sodium intake in elevated blood pressure over short periods of time reduces blood pressure. Long term effects (on mortality, morbidity or blood pressure) of advice to reduce salt in patients with elevated or normal blood pressure are unclear.
Reduced dietary salt for prevention of cardiovascular disease. [2018]Restricting sodium intake in elevated blood pressure over short periods of time reduces blood pressure. Long term effects (on mortality, morbidity or blood pressure) of advice to reduce salt in patients with elevated or normal blood pressure are unclear.
Reduced dietary salt for prevention of cardiovascular disease. [2020]Restricting sodium intake in elevated blood pressure over short periods of time reduces blood pressure. Long term effects (on mortality, morbidity or blood pressure) of advice to reduce salt in patients with elevated or normal blood pressure are unclear.
Reduced dietary salt for prevention of cardiovascular disease. [2020]Restricting sodium intake in elevated blood pressure over short periods of time reduces blood pressure. Long term effects (on mortality, morbidity or blood pressure) of advice to reduce salt in patients with elevated or normal blood pressure are unclear.
Importance of the renin system in determining blood pressure fall with salt restriction in black and white hypertensives. [2022]Seventy-one white and 33 black patients with essential hypertension were studied while on a high sodium intake of 350 mmol/d for 5 days and low sodium intake of 10 mmol/d for 5 days. The fall in blood pressure on changing from the high sodium to the low sodium diet was 17/6 mm Hg in whites and 22/10 mm Hg in blacks. Compared with whites, black patients had a 7-mm Hg greater fall (P
Reducing dietary sodium and decreases in cardiovascular disease in Canada. [2021]Increases in dietary sodium increase blood pressure, whereas emerging evidence confirms that the reduction in dietary sodium results in reduced cardiovascular events.
Salt intake and hypertension therapy. [2013]Hypertension is a risk factor for cardiovascular and renal organ damage. Environmental conditions affect the development of high blood pressure (BP), although genetic influences are also important. Current international guidelines recommend reducing dietary sodium to no more than 100 mmol (about 2.4 g sodium or approximately 6 g salt) per day to prevent BP rising; the current intake of sodium in industrialized countries is approximately double the recommended amount. Clinical trials (DASH and TOHP studies) have shown that dietary factors are fundamental in the prevention and control of BP. Low dietary sodium intake is particularly effective in preventing hypertension in subjects with an increased risk such as the overweight, borderline hypertensives or the elderly. A low-salt diet combined with anti-hypertensive therapies facilitates BP reduction independent of race. The hypotensive effect of calcium channel blockers is less dependent on salt intake than other drugs, such as ACE inhibitors or diuretics. Reduced sodium intake associated with other dietary changes (such as weight loss, and increasing potassium, calcium and magnesium intake) are important instruments for the prevention and therapy of hypertension.
Low sodium diet after DASH: has the situation changed? Dietary Approaches to Stop Hypertension. [2019]The Dietary Approaches to Stop Hypertension (DASH) trial adds to the large body of evidence indicating a direct association of dietary sodium with blood pressure, and showing that rigorous reduction of dietary sodium can reduce blood pressure over a 30-day period by statistically significant amounts. DASH, however, neither addressed nor answered whether a reduction of dietary sodium reduces morbidity and mortality. Data linking baseline sodium to mortality and morbidity outcomes are sparse, with only six known studies. Of these, two showed no association, two showed an inverse association, and two showed a direct association only in obese subsets. No studies have examined outcomes after sodium reduction, and no studies have linked sodium to outcomes or even a blood pressure benefit among treated hypertensives. Universal recommendations for sodium reduction or dietary sodium goals should await evidence that such interventions are both safe and effective as measured by morbidity and mortality outcomes.
The Effects of a Low Sodium Meal Plan on Blood Pressure in Older Adults: The SOTRUE Randomized Feasibility Trial. [2021]Reduced sodium meal plans are recommended by the Centers of Disease Control to lower blood pressure in older adults; however, this strategy has not been tested in a clinical trial. The Satter House Trial of Reduced Sodium Meals (SOTRUE) was an individual-level, double-blind, randomized controlled pilot study of adults living in a congregate living facility subsidized by the Federal Department of Housing and Urban Development (HUD). Adults over age 60 years ate 3 isocaloric meals with two snacks daily for 14 days. The meal plans differed in sodium density (<0.95 vs. >2 mg/kcal), but were equivalent in potassium and macronutrients. Seated systolic BP (SBP) was the primary outcome, while urine sodium-creatinine ratio was used to measure compliance. Twenty participants were randomized (95% women; 95% white; mean age 78 ± 8 years), beginning in 7 October 2019. Retention was 100% with the last participant ending 4 November 2019. Mean baseline SBP changed from 121 to 116 mmHg with the typical sodium diet (-5 mmHg; 95% CI: -18, 8) and from 123 to 112 mmHg with the low sodium diet (-11 mmHg; 95% CI: -15.2, -7.7). Compared to the typical sodium meal plan, the low sodium meal plan lowered SBP by 4.8 mmHg (95% CI: -14.4, 4.9; p = 0.31) and urine sodium-creatinine ratio by 36% (-36.0; 95% CI: -60.3, 3.4; p = 0.07), both non-significant. SOTRUE demonstrates the feasibility of sodium reduction in federally mandated meal plans. A longer and larger study is needed to establish the efficacy and safety of low sodium meals in older adults.
Salt and cardiovascular disease: insufficient evidence to recommend low sodium intake. [2021]Several blood pressure guidelines recommend low sodium intake (5 g/day, while awaiting the results of large randomized controlled trials of sodium reduction on incidence of cardiovascular events and mortality.
Effects of Sodium Reduction and the DASH Diet in Relation to Baseline Blood Pressure. [2022]Both sodium reduction and the DASH (Dietary Approaches to Stop Hypertension) diet, a diet rich in fruits, vegetables, and low-fat dairy products, and reduced in saturated fat and cholesterol, lower blood pressure. The separate and combined effects of these dietary interventions by baseline blood pressure (BP) has not been reported.