Sodium Intake Timing for High Blood Pressure

Overseen By David Pollock, PhD

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: University of Alabama at Birmingham

Must not be taking: Antidepressants, Sleep medications

Disqualifiers: Kidney disease, Elevated BP, Diabetes, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 3 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: Unknown

Duration: 9 days

55 Participants Needed

Trial Summary

What is the purpose of this trial?

Experimental data have shown that timing of sodium intake impacts diurnal patterns of sodium excretion. The purpose of this study is to test the hypothesis that the time of day for salt intake impacts (1) blood pressure rhythms and urinary sodium excretion and (2) circadian timing of factors responsible for blood pressure regulation and cardiometabolic health in obese individuals. These studies will address two aims. The first aim will test the hypothesis that limiting high salt intake prior to sleep increases day-night differences in blood pressure, improves timing of urinary sodium excretion, and improves metabolic risk factors. The second aim will test the hypothesis that limiting high salt intake prior to sleep preferentially improves rhythmicity in peripheral vs. central circadian clock factors linked to renal sodium handling. The proposed hypothesis-driven studies will determine how timing of sodium intake affects diurnal blood pressure and circadian timing of factors responsible for blood pressure control and metabolic health, with the ultimate goal of identifying novel strategies to treat nocturnal hypertension and metabolic disease in obesity.

Will I have to stop taking my current medications?

If you are taking two or more blood pressure medications or supplements regularly, you may not be eligible for the trial. The protocol does not specify if you need to stop other medications, but it seems focused on limiting certain medications.

What data supports the effectiveness of the treatment Oral sodium supplementation for high blood pressure?

The research suggests that changes in sodium intake can affect blood pressure, but the evidence is mixed and not strong enough to recommend sodium changes as a treatment for high blood pressure. Some studies show that reducing sodium can lower blood pressure, but results vary and are not consistent across different groups. ^{1 2 3 4 5}

Is oral sodium supplementation generally safe for humans?

There is no specific safety data on oral sodium supplementation, but studies on sodium intake suggest that extreme changes in sodium levels can affect blood pressure. The safety of sodium manipulation in humans varies, and more research is needed to determine its safety and effects. ^{1 3 5 6 7}

How does oral sodium supplementation differ from other treatments for high blood pressure?

Oral sodium supplementation is unique because it involves adding sodium to the diet, which is contrary to the common approach of reducing sodium intake to manage high blood pressure. This treatment explores the timing and amount of sodium intake, which may have different effects on blood pressure compared to traditional sodium restriction strategies. ^{3 4 5 8 9}

Eligibility Criteria

This trial is for obese African Americans aged 25-45 with a BMI of 30-50. It's not suitable for those with drug/alcohol abuse history, high alcohol consumption, pregnancy, hormone therapy use, sleep medication or antidepressant users, kidney disease sufferers, very high blood pressure individuals (>150/90 mmHg), shift workers, sleep disorder patients (like apnea), major chronic diseases like diabetes or severe anemia.

Inclusion Criteria

My BMI is between 30 and 50.

I am between 25 and 45 years old.

I am between 25 and 45 years old.

Exclusion Criteria

You have a serious mental illness, as determined by a specific evaluation form.

My kidney function is reduced or I have abnormal urine test results.

You have smoked or used tobacco products in the last year.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Run-in Period

Participants consume a standardized diet providing 2.3 g of sodium per day for 7 days

1 week

Treatment

Participants continue the standardized diet for 9 days with additional sodium intake either with dinner or breakfast

9 days

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

Treatment Details

Interventions

• Oral sodium supplementation

Trial Overview The study tests if the timing of salt intake affects blood pressure rhythms and urinary sodium excretion in obese people. Participants will limit salt before bedtime to see if it improves day-night blood pressure differences and metabolic risk factors by influencing circadian clock factors linked to renal sodium handling.

Participant Groups

Group I: Late Sodium Experimental Treatment 1 Intervention

Late sodium load: participants will consume a standardized diet providing 2.3 g of sodium per day for 7 days (run-in period), after which they will continue to consume the standardized diet for the next 9 days and in addition will take 2 g of sodium with dinner each day.

Group II: Early Sodium Experimental Treatment 1 Intervention

Early sodium load: participants will consume a standardized diet providing 2.3 g of sodium per day for 7 days (run-in period), after which they will continue to consume the standardized diet for 9 days and in addition will take 2 g of sodium in the form of salt tablets with breakfast each day.

Oral sodium supplementation is already approved in United States, European Union, Canada for the following indications:

Approved in United States as Sodium supplements for:

• Sodium deficiency
• Hyponatremia

Approved in European Union as Oral sodium for:

• Sodium deficiency
• Hyponatremia
• Dehydration

Approved in Canada as Sodium supplements for:

• Sodium deficiency
• Hyponatremia

Who Is Running the Clinical Trial?

University of Alabama at Birmingham

Lead Sponsor

Trials

1,677

Recruited

2,458,000+

Findings from Research

A 10-week study involving 17 elderly hypertensive subjects showed that a reduction in dietary sodium intake by 80 mmol/day led to a significant decrease in clinic supine systolic blood pressure (SBP).

While moderate sodium restriction was beneficial for some individuals, the overall effect on 24-hour blood pressure was not significant, suggesting that this dietary change may not be effective for all elderly hypertensive patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of moderate sodium restriction on clinic and twenty-four-hour ambulatory blood pressure in elderly hypertensive subjects. Fotherby, MD., Potter, JF.[2019]

Dietary salt significantly impacts blood pressure, making sodium intake a key focus in lifestyle modifications for managing hypertension, but recommendations are complicated by varying study results.

Recent major trials show stronger links between sodium intake and blood pressure than earlier studies, yet methodological limitations in measuring sodium intake and other factors make it challenging to establish clear guidelines for sodium consumption.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dietary salt restriction and blood pressure in clinical trials. Lackland, DT., Egan, BM.[2019]

Extreme changes in sodium intake can affect blood pressure in both people with normal blood pressure and those with high blood pressure, but the evidence is not strong enough to recommend a general reduction in sodium intake for everyone to prevent hypertension.

Studies show mixed results on the effectiveness of sodium restriction for managing hypertension, and many patients are unlikely to stick to a low-sodium diet without significant support, suggesting that low-sodium diets should not be the primary public health recommendation for treating high blood pressure.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Sodium manipulation in the management of hypertension. The view against its general use. Logan, AG.[2019]

In a study of 108 participants, reducing dietary sodium intake from 140 to 60 mmol/d while maintaining a high potassium diet led to a significant decrease in home systolic blood pressure by 2.5 mm Hg, indicating that lower sodium can effectively help manage blood pressure.

The study demonstrated that a low sodium diet (50 mmol/d) combined with high potassium intake (over 80 mmol/d) not only reduced urinary sodium levels but also increased urinary potassium, suggesting that this dietary approach could be beneficial for blood pressure control in the general population.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Decreasing dietary sodium while following a self-selected potassium-rich diet reduces blood pressure. Nowson, CA., Morgan, TO., Gibbons, C.[2018]

Substantial reductions in sodium intake (75 to 100 mmol/d) can lead to modest decreases in blood pressure, with average reductions of about 1 mmHg for diastolic and 3 to 5 mmHg for systolic pressure, based on clinical trial data.

Current evidence does not support routine dietary sodium restriction for either normotensive or hypertensive individuals, as studies show inconsistent results regarding sodium intake's impact on cardiovascular health outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dietary sodium and cardiovascular health in hypertensive patients: the case against universal sodium restriction. Alderman, MH.[2019]

Multiple guidelines from reputable health organizations over the past decade consistently support sodium restriction as an effective strategy for controlling blood pressure.

These guidelines, including those from the American Heart Association and the World Health Organization, emphasize that reducing sodium intake is both feasible and beneficial for overall cardiovascular health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Reduction of sodium intake is a prerequisite for preventing and curing high blood pressure in hypertensive patients - second part: guidelines. De Santo, NG.[2019]

The Satter House Trial of Reduced Sodium Meals (SOTRUE) showed that a low sodium meal plan for 14 days in older adults led to a reduction in seated systolic blood pressure (SBP) from 123 to 112 mmHg, indicating potential benefits for blood pressure management.

While the low sodium diet did lower SBP by 4.8 mmHg compared to a typical sodium diet, the results were not statistically significant, suggesting that further research with a larger sample size and longer duration is necessary to confirm the efficacy and safety of low sodium meals in older adults.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Effects of a Low Sodium Meal Plan on Blood Pressure in Older Adults: The SOTRUE Randomized Feasibility Trial. Juraschek, SP., Millar, CL., Foley, A., et al.[2021]

A study involving 201 normotensive volunteers and 60 untreated hypertensive patients found that a high sodium diet significantly increased blood pressure, with an average rise of 4.5 mmHg in normotensive individuals and 8.4 mmHg in hypertensive individuals.

The results suggest that reducing sodium intake from 200 to 70 mmol/day could lower blood pressure levels in the general population, potentially decreasing the need for medication in those with hypertension.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effect of sodium intake on the blood pressure related to age and sex. Myers, J., Morgan, T.[2019]

In a study of 149 healthy children, restricting dietary sodium intake to 60 mEq/day for 3 months led to a significant decrease in sodium excretion and a small but notable reduction in diastolic blood pressure, indicating that sodium restriction can have a measurable impact on blood pressure in children.

In a separate analysis of 31 children, potassium supplementation resulted in a significant decrease in systolic blood pressure, suggesting that potassium may play a beneficial role in managing blood pressure, although the effects of sodium restriction and potassium supplementation differ.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Blood pressure response to sodium restriction and potassium supplementation in healthy normotensive children. Miller, JZ., Weinberger, MH.[2019]

References

1. Netherlands pubmed.ncbi.nlm.nih.gov

Effects of moderate sodium restriction on clinic and twenty-four-hour ambulatory blood pressure in elderly hypertensive subjects. [2019]

2. United States pubmed.ncbi.nlm.nih.gov

Dietary salt restriction and blood pressure in clinical trials. [2019]

3. Canada pubmed.ncbi.nlm.nih.gov

Sodium manipulation in the management of hypertension. The view against its general use. [2019]

4. United States pubmed.ncbi.nlm.nih.gov

Decreasing dietary sodium while following a self-selected potassium-rich diet reduces blood pressure. [2018]

5. United States pubmed.ncbi.nlm.nih.gov

Dietary sodium and cardiovascular health in hypertensive patients: the case against universal sodium restriction. [2019]

6. United Arab Emirates pubmed.ncbi.nlm.nih.gov

Reduction of sodium intake is a prerequisite for preventing and curing high blood pressure in hypertensive patients - second part: guidelines. [2019]

7. Switzerland pubmed.ncbi.nlm.nih.gov

The Effects of a Low Sodium Meal Plan on Blood Pressure in Older Adults: The SOTRUE Randomized Feasibility Trial. [2021]

8. United States pubmed.ncbi.nlm.nih.gov

The effect of sodium intake on the blood pressure related to age and sex. [2019]

9. United States pubmed.ncbi.nlm.nih.gov

Blood pressure response to sodium restriction and potassium supplementation in healthy normotensive children. [2019]