The Effects of Sodium and Potassium on Blood Pressure, Vascular Function and Renal Function (KaNa)

March 25, 2025 updated by: Marianne Geleijnse, Wageningen University

Study on the Effects of Sodium and Potassium on Blood Pressure, Vascular Function and Renal Function in Untreated (pre)hypertensive Subjects

To determine the effect of (1) increased sodium intake and (2) increased potassium intake on blood pressure, vascular function and renal function in untreated (pre)hypertensive subjects.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This is a randomized, double-blind, placebo controlled cross-over feeding study.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
40

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Netherlands
      • Wageningen, Netherlands, 6703 HD
        • Wageningen University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

40 years to 90 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • (Pre)hypertension, defined as office SBP: 130-159 mmHg;
  • No use of antihypertensive, lipid-lowering, anticoagulant or other cardiovascular medication;
  • Age at start of the ≥ 40 years;

  • Apparently healthy:

    • No reported current or previous metabolic diseases
    • No history of cardiovascular diseases
    • No history of renal, liver or thyroid diseases
    • No history of gastrointestinal diseases
    • No diabetes mellitus
    • Fasting laboratory parameters within normal range: renal function (serum creatinine, ureum), liver function (ALAT, ASAT, ɣ-GT) and serum glucose.

Exclusion Criteria:

  • Body mass index > 40 kg/m²;
  • Smoking
  • Secondary hypertension;
  • Weight loss or weight gain of 5 kg or more during the last 2 months;
  • Usage of non-steroidal anti-inflammatory drugs (aspirin, ibuprofen, naproxen) and not able or willing to stop taking them from at least 4 weeks prior to the study.
  • Medical treatment that may affect blood pressure and not able (or willing) to stop taking them;
  • Women taking oral contraceptives or estrogen replacement therapy
  • Taking nutritional supplements and unwilling to discontinue;
  • Women lactating, pregnant or intend to become pregnant during study;
  • Reported dietary habits: medically prescribed diet, slimming diet;
  • Reported alcohol consumption > 21 units/w (female subjects) or >28 units/w (male subjects);
  • Unable or unwilling to consume one meal every workday at the university, or to consume the prescribed study diet for 13 weeks;
  • Problems with consuming the supplements or following the study guidelines;
  • Unwilling to undergo home or office blood pressure measurements;
  • Recent blood donation i.e. 1 month (male subjects) or 2 months (female subjects) prior to the study and planned donation during the study period;
  • Reported intense sporting activities > 10 h/w;
  • Not agreeing to be informed about unexpected and medically relevant personal test-results
  • Participation in another biomedical trial less than 2 months before the start of the study or at the same time;
  • No informed consent signed.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Sodium
For 4 weeks subjects will consume 3 grams of sodium by the intake of capsules on top of a low-sodium (2 grams of sodium), low-potassium (2 grams of potassium) diet
Dietary supplement: Sodium
Sodium Chloride (provided by Microz, Geleen, Netherlands): 8 capsules per day which equals a sodium intake of 3 grams.
Active Comparator: Potassium
For 4 weeks subjects will consume 3 grams of potassium by the intake of capsules on top of a low-sodium (2 grams of sodium), low-potassium (2 grams of potassium) diet.
Dietary supplement: Sodium
Sodium Chloride (provided by Microz, Geleen, Netherlands): 8 capsules per day which equals a sodium intake of 3 grams.
Drug: Potassium
Potassium Chloride (provided by Microz, Geleen, Netherlands): 8 capsules per day which equals a potassium intake of 3 grams.
Placebo Comparator: Placebo
For 4 weeks subjects will consume placebo capsules (content: cellulose) on top of a low-sodium low-potassium diet
Dietary supplement: Sodium
Sodium Chloride (provided by Microz, Geleen, Netherlands): 8 capsules per day which equals a sodium intake of 3 grams.
Drug: Placebo
Placebo (cellulose, provided by Microz, Geleen, Netherlands): 8 capsules per day.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in Endothelium-dependent flow-mediated dilation comparing (1) high sodium, low potassium intake and (2) low sodium, high potassium intake with low sodium, low potassium intake.
Time Frame: Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
Ultra-sonography (brachial artery) + Picus system
Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in blood pressure comparing (1) high sodium, low potassium intake and (2) low sodium, high potassium intake with low sodium, low potassium intake.
Time Frame: Screening. Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)

Includes:

Office BP (Dinamap, 4 consecutive measurements with 2-min intervals) ABPM (Spacelab; 1x24h, at baseline, week 5, week 9, week 13)
Screening. Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
Change in Pulse Wave Velocity comparing (1) high sodium, low potassium intake and (2) low sodium, high potassium intake with low sodium, low potassium intake.
Time Frame: Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)

Device: SphygmoCor (tonometry)

Parameters: Pulse Wave Velocity and at baseline, week 5, week 9 and week 13
Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
Change in vasomotion comparing (1) high sodium, low potassium intake and (2) low sodium, high potassium intake with low sodium, low potassium intake.
Time Frame: Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
Device: PeriFlux 5000 (Perimed, Sweden0
Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
Change in Biomarkers of endothelial function comparing (1) high sodium, low potassium intake and (2) low sodium, high potassium intake with low sodium, low potassium intake.
Time Frame: Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
Plasma analysis of endothelin-1, ADMA, MCP-1, sVCAM-1, sICAM-1, sE-selectin, sTM, CRP, SAA, IL-6, IL-8, TNF-α, vWF, nitric oxide
Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
Change in renal function comparing (1) high sodium, low potassium intake and (2) low sodium, high potassium intake with low sodium, low potassium intake.
Time Frame: Screening. Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
eGFR, serum creatinine (at screening also used as safety parameter)
Screening. Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
Change in cardiovascular parameters in plasma comparing (1) high sodium, low potassium intake and (2) low sodium, high potassium intake with low sodium, low potassium intake.
Time Frame: Screening. Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
Total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, insulin and glucose (at screening also used as safety parameter)
Screening. Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
Liver function parameters
Time Frame: Screening. Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
Montoring liver function parameters for safety: includes ALAT, ASAT and ɣ-GT
Screening. Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
24-hour urinary mineral excretions
Time Frame: Screening. Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
Sodium and potassium (as compliance markers)
Screening. Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
24-hour excretion of protein, albumin and creatinine
Time Frame: Screening. Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
In addition, protein is assessed in spot urine during screening using a dipstick test
Screening. Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
Adverse events
Time Frame: Every day
Patient diary for occasions of illness, hospitalizations, medication use and other information on potential side effects
Every day
Anthropometric measurements
Time Frame: Screening. Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
Body weight (weekly), height (only at baseline), waist circumference (baseline and every 4 weeks)
Screening. Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
Heart rate
Time Frame: Screening. Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
Dinamap, 4 consecutive measurements with 2-min intervals
Screening. Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
Food frequency questionnaire
Time Frame: Screening
Screening
Change in Pulse Wave Analysis comparing (1) high sodium, low potassium intake and (2) low sodium, high potassium intake with low sodium, low potassium intake.
Time Frame: Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)
Device: SphygmoCor (tonometry)
Baseline at week 1 (t=0). After intervention period 1 at week 5 (t=1). After intervention period 2 at week 9 (t=2). After intervention period 3 at week 13 (t=3)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Wageningen University

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Top Institute Food and Nutrition

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Johanna M Geleijnse, PhD, Wageningen University, Division of Human Nutrition

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2012

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 1, 2012

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 1, 2012

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 20, 2012

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 9, 2012

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 10, 2012

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 1, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 25, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2012

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • KaNa-trial

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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