Cardiovascular Risk Factor
Conditions
Keywords
Potassium, Sodium, Vascular function
Brief summary
The purpose of this study is to determine if dietary potassium can attenuate the deleterious effects of high sodium on blood vessel function in healthy, salt-resistant participants.
Detailed description
Cardiovascular disease remains a major Public Health problem in the U.S. and is the result of diseases such as atherosclerosis and high blood pressure (BP). Several dietary factors have been implicated as risk factors including high sodium and low potassium diets. Indeed, it is well known that excess sodium can increase BP while potassium rich diets have BP lowering properties. While the role of these two nutrients on BP is widely accepted, their impact on the vasculature has received less attention. Endothelial dysfunction, characterized by impaired dilation is an important non-traditional risk factor for atherosclerosis. Data in animal models suggest that salt loading, independent of changes in BP, results in endothelial dysfunction while evidence is mounting that potassium may be beneficial to vascular health. Further, potassium may be more effective in the presence of high sodium however the role of potassium in protecting the vasculature from a high sodium diet in salt-resistant adults has not been explored. A potential mechanism responsible for sodium induced vascular dysfunction is overproduction of reactive oxygen species resulting in reduced nitric oxide (NO) production/ bioavailability. It has been suggested that potassium can counteract sodium's effect by reducing ROS. The central hypothesis is that potassium can protect against the deleterious effects of high sodium on the vasculature by reducing oxidative stress and preserving NO. In this grant, the investigators propose to use a 21-day controlled feeding study to compare the effects of a high sodium diet (300 mmol) combined with either a high (120 mmol) or moderate (65 mmol) amount of potassium and low sodium (50 mmol) combined with moderate potassium (crossover design, diet order sequence randomized) on 2 levels of the vasculature, conduit artery and microvasculature. These experiments will be performed in salt-resistant participants to study the vascular effects alone, independent of changes in BP.
Interventions
7 days of the prescribed diet
7 days of the prescribed diet
7 days of the prescribed diet
Sponsors
University of Delaware
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
NONE
Intervention model description
All participants will complete each arm. It is a crossover, randomized design.
Eligibility
Sex/Gender
ALL
Age
22 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* healthy * normal blood pressure
Exclusion criteria
* hypertension * history of heart disease * diabetes * kidney disease * obese (BMI ≥30) * significant weight changes in the last 6 months * use of tobacco products * pregnant * on a special diet (gluten free; vegan) * take any medications for the above conditions * endurance trained athletes
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Conduit artery endothelial-dependent dilation | on the 7th day of each diet | The change in flow-mediated dilation (FMD) between the 3 diets as assessed by brachial artery FMD |
Other
| Measure | Time frame | Description |
|---|---|---|
| Arterial Stiffness | on 7th day of each diet | Assessed by carotid to femoral artery pulse wave velocity |
| Wave reflection | on 7th day of each diet | Assessed by augmentation index |
| Endothelial cell expression of oxidative stress marker | on the 7th day of each diet | Assessed in venous endothelial cells from participants. |
| Ambulatory blood pressure | 7 days | Assessed by 24 hr ambulatory blood pressure monitoring. |
Countries
United States
Outcome results
None listed