Clinical trial NCT04244604: Vascular Effects of Acute Sodium (VEAS) Study
Official title: The Effects of a High Salt Meal on Blood Flow Regulation
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Sodium Excess
Racial Disparities
Blood Pressure
Cardiovascular Risk Factor
Keywords: blood pressure
racial disparities
cardiovascular health
physical fitness
sleep
dietary sodium
dietary salt
diet
Lead sponsor: Indiana University
Sponsor class: OTHER
Collaborators: name: University of Delaware
First posted: 2020-01-28
Enrollment: 100
Sex: ALL
Minimum age (years): 19
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: The intervention is to provide subjects with either a low sodium meal (140 mg sodium) and a high sodium meal (2500 mg sodium), in a randomized order.
Primary purpose: PREVENTION

Brief summary: This IRB will cover a current clinical trial (NCT04244604) that was started at Auburn University (AU IRB#19-390), the Principal Investigator's prior institution, and is supported by his NIH Career Development Award (NHLBI K01HL147998).

About nine out of ten Americans overconsume dietary salt. Compared to other racial groups, Black individuals are more prone to salt-sensitive hypertension and negative cardiovascular conditions associated with high salt intake. However, there is a critical need to determine the reasons behind and mechanisms that contribute to these racial disparities. Both acute (single meal) and chronic high-dietary sodium cause small but important increases in blood sodium concentration that are associated with altered blood pressure regulation and blood vessel dysfunction. However, racial differences in these measures have not been examined. This is important because Black individuals generally exhibit lower circulating concentrations of hormones (e.g., renin, aldosterone, angiotensin 2) that buffer changes in body sodium to regulate blood pressure, and this could make them more vulnerable to the negative effects of a high-sodium meal.

Therefore, the purpose of this study is to determine whether there are racial differences in blood pressure regulation and blood flow after a high-sodium meal. The investigators will assess blood pressure regulation, blood vessel stiffness, and the blood vessel's ability to dilate before and after a high-salt meal and a low-salt control meal (both meals are low-salt tomato soup with varied added salt). The investigators will also collect blood and urine to measure sodium and determine biochemical changes that may be contributing to racial differences in cardiovascular function.

Detailed description: The investigators have previously used a high-sodium saline infusion to increase blood sodium and consequently increase blood pressure in Black and White individuals. The investigators' prior data suggest that increased blood sodium concentrations result in larger blood pressure elevations for a given elevation in blood sodium levels in Black compared to White adults. In this proposal, the investigators are seeking to translate these previous findings using a single high-salt meal (up to 2500 mg of sodium; similar to a few slices of pizza or a sandwich/burger and side dish). Our primary aims are to determine if the high-sodium meal causes greater 1) blood pressure dysregulation 2) decreases in blood vessel function and 3) larger changes in blood sodium in Black compared to White individuals. Other potential questions that could be determined include aging differences or an influence of fitness. The investigators will not exclude other races/ethnicities as the project will also determine the response of other minority groups (e.g. Asian or Latine/Hispanic adults) to a high-salt meal.

Eligibility criteria: Inclusion Criteria:

1. Are between the ages of 19-75.
2. Have blood pressure no higher than 150/90 mmHg.
3. Have a BMI below 35 Kg/m2 (otherwise healthy)
4. Free from metabolic disease (diabetes or renal disease), pulmonary disorders (e.g., COPD \& cystic fibrosis), and cardiovascular disease (peripheral vascular, cardiac, or cerebrovascular).
5. Do not have any precluding medical issues that prevent participants from exercising (i.e., cardiovascular issues, or muscle/joint issues including painful arthritis) or giving blood (e.g., blood thinners).
6. Are not currently smoking, using smokeless tobacco, nor smoked within the past 12 months.

Exclusion Criteria:

1. High blood pressure - greater the 150/90 mmHg
2. Low blood pressure - less than 90/50 mmHg
3. History of cardiovascular disease
4. History of cancer
5. History of diabetes
6. History of kidney disease
7. Obesity (BMI \> 30 kg/m2)
8. Smoking or tobacco use
9. Current pregnancy
10. Nursing mothers
11. Communication barriers

Primary outcomes:
measure: Changes in flow-mediated dilation (FMD)
timeFrame: Before, 30 minutes, and one hour after soup, both conditions (high- and low- salt)
measure: Changes in indices of arterial stiffness
timeFrame: Before 30 minutes, and one hour after soup, both conditions (high- and low- salt)
measure: Changes in blood pressure reactivity
timeFrame: Before and one hour after soup, both conditions (high- and low- salt)
measure: Changes in blood biomarkers of nitric oxide bioavailability
timeFrame: Before, 30 minutes, and one hour after soup, both conditions (high- and low- salt)
measure: Changes in circulating reactive oxygen species
timeFrame: Before, 30 minutes, and one hour after soup, both conditions (high- and low- salt)
measure: Changes in circulating inflammatory cytokines
timeFrame: Before, 30 minutes, and one hour after soup, both conditions (high- and low- salt)
Secondary outcomes:
measure: Objective sleep duration and quality
timeFrame: Baseline (pre-intervention)
measure: Subjective Sleep duration and quality
timeFrame: Baseline (pre-intervention)
measure: Physical activity
timeFrame: Baseline (pre-intervention)
measure: Cardiorespiratory fitness
timeFrame: Baseline (pre-intervention)
measure: Mental health - social anxiety
timeFrame: Baseline (pre-intervention)
measure: Mental health - depression
timeFrame: Baseline (pre-intervention)
measure: Habitual dietary intake
timeFrame: Baseline (pre-intervention)
Other outcomes:
Locations:
city: Auburn
country: United States
facility: Auburn University
state: Alabama
city: Bloomington
country: United States
facility: Indiana University School of Public Health
state: Indiana
Study officials:
References:
citation: Wenner MM, Paul EP, Robinson AT, Rose WC, Farquhar WB. Acute NaCl Loading Reveals a Higher Blood Pressure for a Given Serum Sodium Level in African American Compared to Caucasian Adults. Front Physiol. 2018 Oct 1;9:1354. doi: 10.3389/fphys.2018.01354. eCollection 2018.
citation: Babcock MC, Robinson AT, Migdal KU, Watso JC, Wenner MM, Stocker SD, Farquhar WB. Reducing Dietary Sodium to 1000 mg per Day Reduces Neurovascular Transduction Without Stimulating Sympathetic Outflow. Hypertension. 2019 Mar;73(3):587-593. doi: 10.1161/HYPERTENSIONAHA.118.12074.
citation: Dickinson KM, Clifton PM, Burrell LM, Barrett PH, Keogh JB. Postprandial effects of a high salt meal on serum sodium, arterial stiffness, markers of nitric oxide production and markers of endothelial function. Atherosclerosis. 2014 Jan;232(1):211-6. doi: 10.1016/j.atherosclerosis.2013.10.032. Epub 2013 Nov 20.
citation: Migdal KU, Robinson AT, Watso JC, Babcock MC, Serrador JM, Farquhar WB. A high-salt meal does not augment blood pressure responses during maximal exercise. Appl Physiol Nutr Metab. 2020 Feb;45(2):123-128. doi: 10.1139/apnm-2019-0217. Epub 2019 Jun 25.