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Completed

NCT Number: NCT01575041

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

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.

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Key information

Conditions

Hypertension Blood Pressure Cardiovascular Diseases Renal Function Vascular Diseases Vascular Function

Age range

40 year–90 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Wageningen University

Wageningen, 6703 HD, Netherlands

About this study

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

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

Sodium

Dietary Supplement

Sodium Chloride (provided by Microz, Geleen, Netherlands): 8 capsules per day which equals a sodium intake of 3 grams.

Potassium

Drug

Potassium Chloride (provided by Microz, Geleen, Netherlands): 8 capsules per day which equals a potassium intake of 3 grams.

Placebo

Drug

Placebo (cellulose, provided by Microz, Geleen, Netherlands): 8 capsules per day.

Primary outcomes

  1. 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

Secondary outcomes

  1. 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)

  2. 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

  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

  4. 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

  5. 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)

  6. 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)

  7. 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

  8. 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)

  9. 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

  10. Adverse events

    Time frame: Every day

    Patient diary for occasions of illness, hospitalizations, medication use and other information on potential side effects

  11. 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)

  12. 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

  13. Food frequency questionnaire

    Time frame: Screening

  14. 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)

Sponsors and collaborators

Lead sponsor

Wageningen University

Other

Collaborators

  • Top Institute Food and Nutrition

Registry information

Official study title

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

Acronym: KaNa

Important dates

Study start
2012
Primary completion
2012
Study completion
2012
First posted
Apr 10, 2012
Registry last updated
Apr 1, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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