Clinical trial NCT02881515: Adverse Neurogenic Actions of Dietary Salt
Official title: Adverse Neurogenic Actions of Dietary Salt
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Blood Pressure
Lead sponsor: University of Delaware
Sponsor class: OTHER
First posted: 2016-08-29
Enrollment: 77
Sex: ALL
Minimum age (years): 21
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: Excess dietary salt increases the risk for cardiovascular events, even in people that are not hypertensive. There is some evidence that excess dietary salt exaggerates blood pressure and sympathetic nervous system responses to various perturbations and increases blood pressure variability. This proposal will examine the effects of low, medium, and high salt diets on cardiovascular reactivity and blood pressure variability.

Detailed description: Excess dietary salt causes target organ damage and increases the risk for adverse cardiovascular (CV) events independent of blood pressure (BP). Recent data in salt-resistant, normotensive rodents suggest that high dietary salt enhances the excitability or gain of sympathetic circuits, exaggerates sympathetic and CV responses to various stimuli, and increases BP variability (BPV). There are limited data regarding the impact of dietary salt intake on sympathetic nerve activity (SNA) and CV function in salt-resistant humans as well as the underlying mechanisms contributing to these adverse effects. The long-term goal is to determine how dietary salt adversely affects BP regulation and CV health. The objective of this proposal is to comprehensively evaluate the impact of dietary salt intake on SNA and CV reactivity and BPV in normotensive humans. The investigators have 2 specific aims: 1) Aim 1 will test the hypothesis that high dietary salt increases SNA and CV reactivity in normotensive adults, 2) Aim 2 will test the hypothesis that high dietary salt increases BPV in normotensive adults. The expected outcome is to demonstrate that dietary salt loading increases CV reactivity and BPV through a sympathetic nervous system mechanism that originates in the brain. The proposed research is significant, as these studies will provide empirical evidence that dietary salt intake impacts neurohumoral control of the circulation in salt-resistant humans. The proposed research is innovative because it will identify a novel neurogenic action of dietary salt in human CV regulation.

Eligibility criteria: Inclusion Criteria:

* normal blood pressure
* men, Women, minorities
* ECG within normal limits
* screening blood panel within normal limits

Exclusion Criteria:

* high blood pressure (\>140/90 mmHg)
* history of cardiovascular disease
* history of cancer
* history of diabetes
* history of kidney disease
* obesity (BMI \> 30 kg/m2)
* smoking or tobacco use
* current pregnancy
* nursing mothers
* communication barriers

Primary outcomes:
measure: Blood Pressure Variability
timeFrame: Day 10 of diet (i.e., after 10 days of low, medium, and high sodium diets; crossover design)
measure: Blood Pressure Reactivity - Handgrip exercise
timeFrame: Day 10 of diet (i.e., after 10 days of low, medium, and high sodium diets; crossover design)
Secondary outcomes:
measure: Blood Pressure Reactivity - Cold Pressor test
timeFrame: Day 10 of diet (i.e., after 10 days of low, medium, and high sodium diets; crossover design)
measure: Sympathetic Responses - Handgrip exercise
timeFrame: Day 10 of diet (i.e., after 10 days of low, medium, and high sodium diets; crossover design)
measure: Sympathetic Responses - Cold Pressor test
timeFrame: Day 10 of diet (i.e., after 10 days of low, medium, and high sodium diets; crossover design)
Other outcomes:
Locations:
city: Newark
country: United States
facility: University of Delaware
state: Delaware
Study officials:
affiliation: University of Delaware
name: William B Farquhar, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Migdal KU, Babcock MC, Robinson AT, Watso JC, Wenner MM, Stocker SD, Farquhar WB. The Impact of High Dietary Sodium Consumption on Blood Pressure Variability in Healthy, Young Adults. Am J Hypertens. 2020 Apr 29;33(5):422-429. doi: 10.1093/ajh/hpaa014.