CClinicalTrials.gg
Active, not recruitingNCT03253172K+ in CKDUpdated Aug 10, 2026

Potassium Supplementation in CKD

An interventional study of Potassium Chloride and Potassium Citrate in Renal Insufficiency, Chronic, Potassium Depletion and Hypertension, sponsored by Erasmus Medical Center. Active, not recruiting at 4 sites in Netherlands. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-10.

Sponsored by Erasmus Medical Center · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
532
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study summary

The current high-sodium, low-potassium diet contributes to the high prevalence of high blood pressure (hypertension). Indeed, the anti-hypertensive effects of potassium supplementation are well-established. Hypertension is even more prevalent and resistant in patients with chronic kidney disease (CKD) and contributes to further decline in kidney function. Four recent epidemiological studies (published 2014 - 2016) showed that higher dietary potassium intake was associated with better renal outcomes. All studies recommended an intervention study with potassium supplementation in patients with CKD, but this has not been performed. The aim of this study is to study the renoprotective effect of potassium supplementation in patients with CKD (stage 3b or 4, i.e. estimated glomerular filtration rate [eGFR] 15 - 45 ml/min/1.73 m2).

02

Conditions studied

  • Renal Insufficiency, Chronic
  • Potassium Depletion
  • Hypertension
  • Hyperkalemia
03

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • CKD 3b or 4 (45 - 15 ml/min/1.73 m2)
  • Δ eGFR (as estimated by the CKD-EPI equation) > 2 ml/min/1.73 m2/year (in preceding ≥ 1 year with at least 3 measurements)
  • Hypertension (defined as office blood pressure > 140/90 mmHg or use of anti-hypertensive medication)

Exclusion criteria

Exclusion Criteria:

  • Hyperkalemia (serum potassium > 5.5 mmol/l) at study visit V0
  • Medical reasons to continue dual RAAS-blockade, mineralocorticoid receptor blockers, potassium-sparing diuretics, or oral potassium binders.
  • Patients with previous history of ventricular cardiac arrhythmia
  • Patients with a life expectancy \< 6 months
  • Expected initiation of renal replacement therapy \< 2 years
  • Incapacitated subjects
  • Women who are pregnant, breastfeeding or consider pregnancy in the coming 2 years.
04

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Double (Participant, Investigator)
Enrollment
532 participants (estimated)

Study arms

  • Placebo comparator
    Placebo

    Placebo

    Dietary Supplement: Placebo

  • Experimental
    Potassium Chloride

    Experimental Arm 1 - Rationale is that most evidence for a positive effect of potassium comes from studies using potassium chloride

    Dietary Supplement: Potassium Chloride

  • Experimental
    Potassium Citrate

    Experimental Arm 2 - Rationale for citrate is that recent evidence indicates that alkali treatment may also be renoprotective.

    Dietary Supplement: Potassium Citrate

Interventions

  • Dietary supplementPotassium Chloride

    Two potassium supplements with varying anions.

  • Dietary supplementPotassium Citrate

    Potassium Citrate

  • Dietary supplementPlacebo

    Placebo

05

What researchers measure

Primary outcomes

  1. Difference in estimated glomerular filtration rate (eGFR)

    Time frame: Two years

Secondary outcomes

  1. ≥ 30% decrease in eGFR

    Time frame: Two years

  2. Slope analysis (change in eGFR in ml/min/1.73 m2/year)

    Time frame: Two years

  3. Doubling in serum creatinine or kidney failure (CKD stage 5 or start of kidney replacement therapy)

    Time frame: Two years

  4. Progression to next CKD or albuminuria class

    Time frame: Two years

  5. Ambulatory (24-hour) blood pressure

    Time frame: Two years

  6. Spot urine albumin to creatinine ratio (UACR)

    Time frame: Two years

  7. Cardiovascular event

    Coronary heart disease death, fatal myocardial infarction, fatal stroke and other cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, unstable angina, resuscitated cardiac arrest

    Time frame: Two years

  8. All-cause mortality

    Time frame: Two years

  9. Incidence of hyperkalemia

    Time frame: Two years

  10. NT-pro-BNP

    Volume marker 1

    Time frame: Two years

  11. Bioimpedance measures

    Volume marker 2

    Time frame: Two years

  12. Pulse-wave velocity

    Cardiovascular marker 1

    Time frame: Two years

  13. High-sensitive CRP

    Cardiovascular marker 2

    Time frame: Two years

Other outcomes

  1. Effects of 2-week KCl supplementation on plasma potassium (mmol/l)

    Run-in outcome 1

    Time frame: Two weeks

  2. Incidence of Hyperkalemia after 2-week KCl supplementation

    Run-in outcome 2

    Time frame: Two weeks

  3. Effects of 2-week KCl supplementation on office blood pressure (mmHg)

    Run-in outcome 3

    Time frame: Two weeks

06

Study locations

4 sites
  • Academic Medical Center Amsterdam
    Amsterdam, Netherlands
  • University Medical Center Groningen
    Groningen, Netherlands
  • Leiden University Medical Center
    Leiden, Netherlands
  • Erasmus MC
    Rotterdam, Netherlands
07

References and documents

Publications

  • Sunga CGG, Zelnick LR, Bansal N. Urinary Sodium and Potassium Excretion and the Risk of Cardiovascular Events in CKD. Kidney360. 2026 Jan 1;7(1):94-106. doi: 10.34067/KID.0000000943. Epub 2025 Aug 8. PubMed 40779318 ↗
  • Gritter M, Wouda RD, Yeung SMH, Wieers MLA, Geurts F, de Ridder MAJ, Ramakers CRB, Vogt L, de Borst MH, Rotmans JI, Hoorn EJ; on behalf of K onsortium. Effects of Short-Term Potassium Chloride Supplementation in Patients with CKD. J Am Soc Nephrol. 2022 Sep;33(9):1779-1789. doi: 10.1681/ASN.2022020147. Epub 2022 May 24. PubMed 35609996 ↗

Individual participant data

Plan to share: Undecided

08

Registry details

Key details

Study ID
NCT03253172
Lead sponsor
Erasmus Medical Center
Collaborators
Dutch Kidney Foundation, University Medical Center Groningen, Leiden University Medical Center, Amsterdam UMC
Responsible party
Ewout Hoorn (Coordinating PI, Erasmus Medical Center) — Principal investigator
First posted
Aug 17, 2017
Start date
Jul 1, 2017
Primary completion
Sep 1, 2026 (estimated)
Completion
Oct 1, 2026 (estimated)
Last update
Aug 10, 2026

Study contacts

Ewout J Hoorn, MD, PhD
principal investigator · Erasmus Medical Center

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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This study is active, not recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.

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