Sodium, Nocturnal Blood Pressure and Nocturnal Pauses in Breathing

Study Overview
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Brief Summary
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A reduction of dietary sodium intake reduces blood pressure and risk of cardiovascular disease.

Detailed Description
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A reduction of dietary sodium intake reduces blood pressure and risk of cardiovascular disease. Patients with hypertension resistant of antihypertensive treatment have a high frequency of non-dipping and obstructive sleep apnoea (OSA). The aim of this project is to analyse the effect of dietary sodium restriction on nocturnal blood pressure and nocturnal pauses in breathing in this patients population.

Official Title
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Sodium, Nocturnal Blood Pressure and Nocturnal Pauses in Breathing

Conditions
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Sodium Imbalance, Nocturnal Blood Pressure, Obstructive Sleep Apnea of Adult

Intervention / Treatment
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* Behavioral: Dietary sodium restriction


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 24h blood pressure > 130/80 mmHg under antihypertensive treatment with three agent, one of these being diuretic. Blood pressure measurement completed after observed intake of antihypertensive medication. unchanged antihypertensive treatment for three months estimated glomerular function >45 mL/min/1.73 m2 Exclusion Criteria: Heart failure assessed from NYHA classification (grade 3-4) Presence of clinically significant peripheral edema In treatment for obstructive sleep apnea Chronic obstructive pulmonary disease (FEV1 <50%) Antihypertensive therapy that can not be taken once daily Pregnancy or breastfeeding Β-albumin <34 g / l U-albumin creatinine ratio> 1000 mg / g INR> 1.2 (if marevan treatment: ALAT> 200) Gluten allergy (dietary guidelines are not adjusted to this group)

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Not blinded cross over trial. First arm is usual diet for two weeks, second arm is sodium dietary restriction.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Dietary sodium restriction<br>DIetary sodium restriction | Behavioral: Dietary sodium restriction<br>* Selfemployed dietary sodium restriction<br>|
| No Intervention: Usual diet<br>Usual diet | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in nocturnal systolic blood pressure | Comparison of blood pressure measured by 24 hour blood pressure measurements at baseline conditions (after two weeks of usual diet) and intervention (after two weeks of dietary sodium restriction) | from day 14 to day 28 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in day (systolic and diastolic) and 24h blood pressure (systolic and diastolic) | Comparison of blood pressure measured by 24h blood pressure measurements at baseline conditions (after two weeks of usual diet) and intervention (after two weeks of dietary sodium restriction) | from day 14 to day 28 | 
| Changes in number of nocturnal pauses in breathing (apnoea hypopnoea index, AHI) | Comparison of apnoea hypopnoea index measured by cardio respiratory monitoring at baseline conditions (after two weeks of usual diet) and intervention (after two weeks of dietary sodium restriction) | from day 14 to day 28 | 
| Changes in day:night sodium urinary sodium excretion | Comparison of baseline conditions (after two weeks of usual diet) and intervention (after two weeks of dietary sodium restriction) | from day 14 to day 28 | 
| Changes in urinary excretion of aquaporin-2 (U-AQP2) og epithelial sodium channel (u-ENaCɣ) | Comparison of baseline conditions (after two weeks of usual diet) and intervention (after two weeks of dietary sodium restriction) | from day 14 to day 28 | 
| Changes in endothelial function (nitric oxide (NO), erythrocyte sodium sensitivity) | Comparison of biomarkers from blood samples drawn at baseline conditions (after two weeks of usual diet) and intervention (after two weeks of dietary sodium restriction) | from day 14 to day 28 |