The Effect of High and Low Sodium Intake on Urinary Aquaporin-2 in Essential Hypertension

Study Overview
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Brief Summary
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The aim of the study is to test the following hypotheses: that the function and/or regulation of AQP2 and/or ENaC in the principal cells is abnormal in essential hypertension. if an abnormal function of the principal cells is present in essential hypertension, this will become more pronounced at high and low sodium intake.

Official Title
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The Effect of High and Low Sodium Intake on Urinary Aquaporin-2 in Essential Hypertension, During Basal Conditions and After Hypertonic Saline Infusion.

Conditions
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Essential Hypertension and Healthy Controls

Intervention / Treatment
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* Behavioral: high sodium diet
* Behavioral: Low Sodium Diet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Caucasian men and women Age 18-65 years Arterial hypertension Body mass index between 18.5 and 30 kg/m2 Exclusion Criteria: Secondary hypertension Isolated systolic hypertension History or clinical signs of AMI, atrial fibrillation, disease of the heart valves, or chronic heart failure. Malignant disease Prior apoplexy alcohol or drug abuse Drug use except antihypertensives and oral contraceptives Abnormal biochemical screening of the blood regarding: red and white blood count, s-creatinine (> 200 micromol/L), b-hemoglobin, p-Sodium, p- potassium, p-albumine, p-bilirubin, p-alanine aminotransferase, p-alkaline phosphatase, p-cholesterol and b-glucose. Abnormal screening of the urine regarding: Blood, albumine and glucose. abnormal electrocardiogram Blood donation within one month of the first examination day Unwillingness to participate

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Intervention/Treatment |
| --- |
|Behavioral: high sodium diet|250-350 mmol|
|Behavioral: Low Sodium Diet|25-35 mmol|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| u-AQP-2 |  | Before and after hypertonic saline infusion after 4 days on high and low sodium diet, respectively. | 
| fractional sodium excretion |  | Before and after hypertonic saline infusion after 4 days on high and low sodium diet, respectively. | 
| p-vasopressin |  | Before and after hypertonic saline infusion after 4 days on high and low sodium diet, respectively. | 
| p-aldosterone |  | Before and after hypertonic saline infusion after 4 days on high and low sodium diet, respectively. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| u-p-AQP-2 |  | Before and after hypertonic saline infusion after 4 days on high and low sodium diet, respectively. | 
| u-ENaC(alfa,beta,gamma) |  | Before and after hypertonic saline infusion after 4 days on high and low sodium diet, respectively. | 
| CH2O |  | Before and after hypertonic saline infusion after 4 days on high and low sodium diet, respectively. | 
| u-cAMP |  | Before and after hypertonic saline infusion after 4 days on high and low sodium diet, respectively. | 
| uPGE2 |  | Before and after hypertonic saline infusion after 4 days on high and low sodium diet, respectively. | 
| GFR |  | Before and after hypertonic saline infusion after 4 days on high and low sodium diet, respectively. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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urinary aquaporin-2, ENaC, fractional sodium excretion, High/low sodium diet