Salt Intake for High Blood Pressure Differences by Race

No longer recruiting at 2 trial locations

Overseen By Austin Robinson, PhD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Indiana University

Disqualifiers: Hypertension, Cardiovascular disease, Diabetes, Obesity, others

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

Compensation: Varies

Number of Visits: 3

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to explore racial differences in blood pressure regulation after consuming a high-salt meal. Researchers seek to understand why Black individuals might experience more salt-sensitive hypertension (high blood pressure from excessive salt) compared to other racial groups. Participants will consume both a high-sodium and a low-sodium tomato soup meal while doctors monitor their blood pressure and blood vessel responses. The trial is suitable for individuals aged 19-40 with normal blood pressure, a healthy weight, and no serious health conditions like diabetes or heart disease. As an unphased trial, it offers participants the chance to contribute to important research that could enhance understanding and treatment of hypertension across different racial groups.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. However, it does mention that participants should not have any medical issues that prevent them from exercising or giving blood, which might imply some medication restrictions.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research shows that consuming too much salt can raise blood pressure, leading to hypertension. This condition increases the risk of heart disease and stroke. Studies have found that people who consume a lot of salt often have higher blood pressure. However, reducing salt intake, even slightly over a few weeks, can significantly lower blood pressure.

The main safety concern with excessive salt intake is its impact on blood pressure and heart health. In this trial, participants will consume meals with specific salt amounts to observe effects on blood pressure and blood vessel function. This method, commonly used to study salt's impact on the body, is generally well-tolerated. No new drugs or treatments are being tested, only dietary changes.

While excessive salt consumption can be harmful over time, the controlled setting of this trial helps manage any risks. Researchers closely monitor participants to ensure their safety. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about this trial because it aims to uncover how different salt levels in meals affect blood pressure differently across racial groups. Unlike current treatments for high blood pressure, which often involve medications like ACE inhibitors or diuretics, this approach focuses on dietary sodium intake as a key factor. By understanding the body's immediate reaction to high and low sodium meals, scientists hope to develop more personalized dietary recommendations that could complement or even enhance existing treatments for better blood pressure management.

What evidence suggests that this trial's treatments could be effective for high blood pressure differences by race?

Research has shown that excessive salt intake can significantly impact blood pressure, particularly in Black individuals. Studies have found that Black people often experience a stronger increase in blood pressure from salt compared to other racial groups. This is partly due to typically lower levels of certain hormones that help manage salt in the body. In this trial, participants will consume meals with varying sodium levels to assess these effects. Specifically, one study discovered that after eating a salty meal, Black participants experienced a greater rise in blood pressure than others. This suggests that high blood pressure related to salt intake might be more common and severe in Black individuals. ^{6 7 8 9 10}

Who Is on the Research Team?

Austin T Robinson, PhD

Principal Investigator

Auburn University

Are You a Good Fit for This Trial?

This trial is for non-smoking individuals aged 19-75 with a BMI below 35 and no history of metabolic, pulmonary, or cardiovascular diseases. Participants must have blood pressure under 150/90 mmHg and be free from conditions that limit exercise or blood donation.

Inclusion Criteria

I don't have health issues that stop me from exercising or giving blood.

My BMI is under 35.

I am between 19 and 75 years old.

Exclusion Criteria

I have had cancer in the past.

I have a history of heart disease.

Your blood pressure is lower than 90/50 mmHg.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Baseline Assessment

Participants undergo baseline assessments including cardiorespiratory fitness, physical activity, habitual dietary intake, and mental health evaluations

1 week

1 visit (in-person)

Intervention

Participants consume a high-sodium meal and a low-sodium control meal, with assessments of blood pressure, vascular function, and blood samples before and after each meal

1 day per meal

2 visits (in-person)

Follow-up

Participants are monitored for changes in blood pressure regulation, blood vessel function, and biochemical markers after the intervention

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Acute Salt (sodium chloride)

Trial Overview

The study investigates how dietary salt affects blood vessel function and blood pressure regulation differently in black versus white individuals. It also examines the impact of lifestyle factors like sleep, physical activity, and nutrition on these racial differences.

How Is the Trial Designed?

Group I: Low Sodium Meal (140 mg sodium), then High Sodium Meal (2500 mg sodium) Experimental Treatment 2 Interventions

On experimental visit days, participants will consume each of the experimental meals, in this order. Prior to, and at several timepoints after consumption, they will have sympathetic nerve activity, vascular function, blood pressure and blood samples (from intravenous catheters) assessed.

Group II: High Sodium Meal (2500 mg sodium), Then Low Sodium Meal (140 mg sodium) Experimental Treatment 2 Interventions

On experimental visit days, participants will consume each of the experimental meals, in this order. Prior to, and at several timepoints after consumption, they will have sympathetic nerve activity, vascular function, blood pressure and blood samples (from intravenous catheters) assessed.

Who Is Running the Clinical Trial?

Indiana University

Lead Sponsor

Trials

1,063

Recruited

1,182,000+

Auburn University

Lead Sponsor

Trials

81

Recruited

14,600+

University of Delaware

Collaborator

Trials

167

Recruited

25,700+

National Heart, Lung, and Blood Institute (NHLBI)

Collaborator

Trials

3,987

Recruited

47,860,000+

Published Research Related to This Trial

Long-term high dietary salt intake is linked to increased blood pressure (BP) and a higher prevalence of hypertension, with evidence from both observational and randomized controlled studies.

Reducing salt intake in the population could lead to lower average BP levels and decrease the risk of cardiovascular complications associated with hypertension, potentially improving health outcomes as hypertension affects over 30% of adults and increases with age.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Reducing food salt content--a neglected approach to hypertension prevention and treatment in the population]. Horký, K.[2009]

The study analyzed 180 canteen meals from 15 worksites and found that the average salt content was 3.8 g per meal for men and 2.8 g per meal for women, indicating a high intake that could contribute to elevated blood pressure.

Fast food samples showed even higher salt levels, averaging 13.8 g per 10 MJ, with some items like sausages containing up to 16.3 g per 10 MJ, highlighting the need for reduced salt content in both canteen and fast food meals.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Salt content in canteen and fast food meals in Denmark. Rasmussen, LB., Lassen, AD., Hansen, K., et al.[2021]

High dietary salt intake is linked to increased risks of hypertension, cardiovascular diseases, and possibly obesity and stomach cancer, with current global intakes averaging 9-12 g per day, significantly above the WHO recommendation of less than 5 g per day.

Reducing salt intake to 5-6 g per day can lower blood pressure and morbidity rates, especially in salt-sensitive individuals, and should be accompanied by increased potassium intake from fruits and vegetables to further support blood pressure management.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Impact of Salt Intake on the Pathogenesis and Treatment of Hypertension. Rust, P., Ekmekcioglu, C.[2017]

Global sodium intake levels are alarmingly high, with most adult populations consuming over 100 mmol/day, and many, especially in Asian countries, exceeding 200 mmol/day, which is well above the physiological need of 10-20 mmol/day.

The primary sources of dietary sodium differ by region, with manufactured foods contributing approximately 75% of sodium intake in Europe and North America, while home-added salt and soy sauce are major sources in Japan and China, highlighting the need for targeted public health policies to reduce sodium consumption.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Salt intakes around the world: implications for public health. Brown, IJ., Tzoulaki, I., Candeias, V., et al.[2023]

Recent research has strengthened the connection between high salt intake and high blood pressure, indicating that reducing salt consumption may help manage hypertension.

Additionally, there is growing evidence that salt can have harmful effects on health that are not related to blood pressure, suggesting that limiting salt intake could provide broader health benefits.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dietary salt restriction: benefits for cardiovascular disease and beyond. Cappuccio, FP., MacGregor, GA.[2019]

Population studies indicate that high salt intake does not consistently correlate with negative health outcomes, despite common beliefs about its risks.

Extreme salt reduction may lower blood pressure in hypertensive individuals, but its effect is significantly less than that of antihypertensive medications, and other lifestyle changes like diet and weight loss are more effective and easier to implement.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Should dietary salt restriction be a basic component of antihypertensive therapy? Graudal, N., Galløe, A.[2019]

In a study analyzing dietary intake and blood pressure of 1928 black and 9739 white adults, it was found that black individuals had a higher sodium/potassium ratio despite lower absolute sodium and potassium intakes compared to whites.

The research suggests that the higher blood pressure and prevalence of hypertension in black adults may be linked to their relatively low potassium intake rather than higher sodium intake, indicating a potential greater sensitivity to sodium's effects on blood pressure.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Blood pressure in blacks and whites and its relationship to dietary sodium and potassium intake. Frisancho, AR., Leonard, WR., Bollettino, LA.[2022]

In a study comparing table salt sales in supermarkets across different racial communities in Houston, it was found that sales in predominantly black and Hispanic areas were 50-100% higher than in predominantly white areas, suggesting higher dietary sodium intake.

The findings raise questions about the potential link between increased table salt consumption and the higher prevalence of hypertension in black populations, but further research is needed to establish a causal relationship.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Ethnic patterns of salt purchase in Houston, Texas. Kerr, GR., Amante, P., Decker, M., et al.[2022]

Reducing dietary salt (NaCl) intake to a moderate level of 6 g/day is recommended for patients with hypertension or cardiovascular conditions, as it effectively lowers blood pressure.

However, there is insufficient evidence to suggest that reducing salt intake significantly impacts cardiovascular mortality, and for patients with fewer health issues, consuming up to 10 g/day of salt appears to be safe.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Salt restriction in people with hypertension and patients with cardiovascular disease : meaningfulness and extent]. Hoyer, J.[2018]

Excessive table salt intake is a significant factor in increasing blood pressure and is linked to various health issues, including arterial hypertension, coronary artery disease, and organ damage, as confirmed by numerous epidemiological and clinical studies.

Reducing salt intake can lead to lower blood pressure and decreased cardiovascular risks, and is beneficial for overall health, suggesting that public health initiatives should focus on promoting lower salt consumption alongside other lifestyle changes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Salt--hidden poison in everyday meal]. Jelaković, B., Premuzić, V., Skupnjak, B., et al.[2009]

Citations

1.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC11414742/

Unpacking Racial Differences in Salt-Sensitive Hypertension

To review underlying mechanisms and environmental factors that may influence racial disparities in the development of salt-sensitive blood pressure.

2.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC8627459/

Differential influences of dietary sodium on blood pressure ...

These data suggest the DASH diet may minimize racial differences in blood pressure responses to sodium manipulation (28, 29). In addition, Morris et al (33) ...

3.

frontiersin.org

frontiersin.org/journals/physiology/articles/10.3389/fphys.2018.01354/full

Acute NaCl Loading Reveals a Higher Blood Pressure for ...

In conclusion, acute increases in serum sodium via hypertonic saline resulted in greater BP responsiveness in African American participants for a given level of ...

4.

sciencedirect.com

sciencedirect.com/science/article/abs/pii/S156607022100103X

Differential influences of dietary sodium on blood pressure ...

Non-Hispanic Black men and women have higher rates of hypertension compared to non-Hispanic White men and women and other racial/ethnic groups. In aggregate, ...

5.

jamanetwork.com

jamanetwork.com/journals/jamanetworkopen/fullarticle/2816740

Sodium Intake and Mortality Among Black and White US ...

80% of low-income Black and White Americans exceeded the recommended daily intake of sodium, which was associated with 10% to 30% of cardiovascular disease ...

6.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC7384997/

Is too much salt harmful? Yes - PMC - PubMed Central

People with a higher salt consumption had a higher average BP and a greater increase of BP with age. The relationship between dietary salt ...

7.

ahajournals.org

ahajournals.org/doi/10.1161/HYPERTENSIONAHA.123.17959

Salt Sensitivity: Causes, Consequences, and Recent ...

Excess salt intake leads to elevation in blood pressure which drives cardiovascular morbidity and mortality.

8.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC6770596/

Sodium Intake and Hypertension - PMC - PubMed Central - NIH

A large meta-analysis [9] showed that modest reduction in salt intake for four or more weeks causes a significant fall in BP in both hypertensive and ...

9.

escardio.org

escardio.org/Journals/E-Journal-of-Cardiology-Practice/Volume-22/salt-and-hypertension-current-views

Salt and hypertension: current views

The association between sodium consumption and hypertension is well known, as high sodium intake can negatively affect control of hypertension.

10.

nutritionsource.hsph.harvard.edu

nutritionsource.hsph.harvard.edu/salt-and-sodium/

Salt and Sodium - The Nutrition Source

But too much sodium in the diet can lead to high blood pressure, heart disease, and stroke. It can also cause calcium losses, some of which may be pulled from ...