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Autosomal Dominant Polycystic KidneyPhase 4TRAMPOLINENCT05228574

Treatment of Vascular Stiffness in ADPKD

A Phase 4 study testing Sodium chloride (NaCl) and Amiloride Hcl 5mg Tab in people with Autosomal Dominant Polycystic Kidney, run by Erasmus Medical Center at 1 site in Netherlands.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disease characterized by cystic kidneys and caused by mutations in the polycystic kidney disease and other rare genes. It is associated with salt-sensitive hypertension, which accounts for the majority of morbidity and mortality. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Autosomal Dominant Polycystic Kidney
What is being tested?
Sodium chloride (NaCl) and Amiloride Hcl 5mg Tab
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
46 participants
Where
1 siteNetherlands
Study dates
11 Mar 2022to 18 Jun 2025
Phase
Phase 4
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Adults with typical ADPKD diagnosed based on Ravine criteria and/or a documented Pkd 1 or 2 mutation
  • Chronic kidney disease epidemiology collaboration equation estimated glomerular filtration rate ≥60 ml/min/1.73m2
  • Ability to provide informed consent

Who cannot join

  • Uncontrolled hypertension, defined as an office blood pressure of ≥160/ ≥90 mmHg with or without antihypertensive treatment
  • Concomitant use of ≥ 3 antihypertensive medications
  • When antihypertensive treatment is prescribed for any other treatment indication than hypertension (e.g. cardia arrhythmia)
  • Serum potassium levels >5.5 mmol/L (measured within last 6 months)
  • History of liver disease (excluding liver cysts due to ADPKD)
  • History of heart failure (cardiac ejection fraction < 35%) or cardiac arrhythmia
Show all 11Show fewer
  • History of diabetes mellitus
  • Active infection or antibiotic therapy
  • Immunosuppressive therapy within the last year
  • Concomitant use of drugs that could influence blood pressure and/or disease progression (Tolvaptan/non-steroidal anti-inflammatory drugs (NSAIDs)/chemotherapy), excluding < 3 antihypertensive drugs
  • Actual pregnancy or unwillingness to adhere to reproductive precautions during the duration of the study

Trial locations and contacts

1 site in 1 country.

Netherlands1 site
  • Erasmus University Medical Centre Rotterdam

    Rotterdam, South Holland, 3015GD

Other trials in Netherlands

About this study

Official title: Treatment of Vascular Stiffness in Patients With Autosomal Dominant Polycystic Kidney Disease

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disease characterized by cystic kidneys and caused by mutations in the polycystic kidney disease and other rare genes. It is associated with salt-sensitive hypertension, which accounts for the majority of morbidity and mortality. About 70% of patients with ADPKD develop hypertension, prior to the onset of kidney function decline. Early onset hypertension, despite its treatment, is independently associated with rapid kidney function decline. The investigators hypothesize that a high-sodium diet in patients with ADPKD is required for the development of vascular stiffness, which precedes hypertension, and that treatment with amiloride reverses this phenomenon.

Read the detailed description

Objective of the study:

The investigators aim to investigate if arterial stiffness is exacerbated due to a high-salt diet in patients with ADPKD. The investigators also aim to explore whether treatment with amiloride prevents the arterial stiffness caused by a high-salt diet.

Study design:

Randomized, double blinded and placebo-controlled clinical trial with open-label treatment with amiloride

Study population:

Adults with ADPKD with an estimated glomerular filtration rate (CKD-EPI) of ≥ 60 ml/min/1.73m2

Intervention:

All participants will be subjected to a low-salt diet (3,5 grams/day) throughout the study for a total of 6 weeks. After a run-in period of 2 weeks, participants will be randomized into two treatment groups:

Group 1: Sodium chloride capsules (6 grams/day) for 2 weeks, combined with amiloride (20 mg/day) in last 2 weeks Group 2: Placebo capsules for 2 weeks, combined with amiloride (20 mg/day) in last 2 weeks.

Primary study parameters/outcome of the study:

The three primary outcomes of this study are a difference in central arterial stiffness (pulse wave velocity, PWV) between:

  1. The high-salt group versus low-salt group;
  2. The high-salt group: before versus after amiloride treatment;
  3. The low-salt group: before versus after amiloride treatment.

The burden of participation includes:

  • A dietary salt restriction of 3.5 grams/day for a total period of 6 weeks
  • Salt supplementation or placebo for a total period of 4 weeks
  • Drug intervention with amiloride during the last 2 weeks
  • Hospital visits
Being tested
Sodium chloride (NaCl), Placebo, Amiloride Hcl 5mg Tab
Keywords
Polycystic kidney disease, Amiloride, Salt, Hypertension
Medical subject headings
Polycystic Kidney, Autosomal Dominant, Polycystic Kidney Diseases, Hypertension

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Sodium chloride (NaCl)Dietary supplement

    Also called Table salt

    Sodium chloride capsules 6 grams per day for 4 weeks.

  • PlaceboDietary supplement

    Placebo capsules, 6 grams per day for 4 weeks.

  • Amiloride Hcl 5mg TabDrug

    Also called Amiloride

    Amiloride 5mg tablets, 20 mg per day for two weeks in open-label setting.

Study groups in NCT05228574
Study groupRoleWhat they receive
High-salt group (group 1)Active comparatorAll participants will be subjected to a low-salt diet (3.5 grams/day) for six weeks. Group 1 will receive sodium chloride capsules (6 grams/day) for four weeks. In the last two weeks of the trial, all participants will be treated with amiloride tablets (20 mg daily) in open-label setting.
Low-salt group (group 2)Placebo comparatorAll participants will be subjected to a low-salt diet (3.5 grams/day) for six weeks. Group 2 will receive placebo capsules (6 grams/day) for four weeks. In the last two weeks of the trial, all participants will be treated with amiloride tablets (20 mg daily) in open-label setting.
Receives: Dietary Supplement: Placebo; Drug: Amiloride Hcl 5mg Tab

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Arterial stiffness induced by high salt diet

    Difference in central arterial stiffness, measured as the pulse wave velocity (PWV), in high-salt group versus low-salt group.

    Measured: At week 3, week 5

  2. Effect of treatment with amiloride on arterial stiffness in high-salt group

    Difference in central arterial stiffness, measured as the pulse wave velocity (PWV), before versus after amiloride treatment in high-salt group.

    Measured: At week 5 and at week 7

  3. Effect of treatment with amiloride on arterial stiffness in low-salt group

    Difference in central arterial stiffness, measured as the pulse wave velocity (PWV), before versus after amiloride treatment in low-salt group.

    Measured: At week 5 and at week 7

Secondary outcomes (4)
  1. Blood pressure

    24-hours ambulatory blood pressure measurement (Mobil-O-Graph).

    Measured: At week 3, week 5 and at at week 7

  2. Salt tasting thresholds

    Sodium chloride (NaCl) solutions with different concentrations to assess the salt tasting thresholds.

    Measured: At inclusion, week 3, week 5 and at week 7

  3. Skin sodium accumulation

    In a subgroup of participants, tissue sodium concentration (23Na) will be assessed noninvasively using a contrast-free 23 Na-MRI scan.

    Measured: At week 3, week 5 and at week 7

  4. Markers of (vascular) inflammation and endothelial dysfunction

    Blood biomaterials will be collected at the visits. We will measure inflammatory markers including the high-sensitivity C-reactive protein, interleukin-6 and tumor necrosis factor-α, and other relevant markers for endothelial dysfunction including the adhesion molecules intercellular cell adhesion molecules-1, vascular cell adhesion molecules-1 and endothelin-1.

    Measured: At inclusion, week 3, week 5 and at week 7

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted8 Feb 2022
  2. Study start11 Mar 2022
  3. Primary completion18 Jun 2025
  4. Study completion18 Jun 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 4
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Model description
This is a single-centre, randomized, double-blinded, and placebo-controlled clinical trial with a secondary open-label part.
Masking
Triple blind
Who is masked
Participant, Care provider, Investigator
Enrolment
46 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05228574
Sponsor's protocol ID
NL72836.340.10
Acronym
TRAMPOLINE
Status last verified
Aug 2025
First submitted
12 Jan 2022
Last updated
17 Aug 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • St Pierre K, Cashmore BA, Bolignano D, Zoccali C, Ruospo M, Craig JC, Strippoli GF, Mallett AJ, Green SC, Tunnicliffe DJ. Interventions for preventing the progression of autosomal dominant polycystic kidney disease. Cochrane Database Syst Rev. 2024 Oct 2;10(10):CD010294. doi: 10.1002/14651858.CD010294.pub3.

    PubMed 39356039

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing Sodium chloride (NaCl) and Amiloride Hcl 5mg Tab in people with Autosomal Dominant Polycystic Kidney, run by Erasmus Medical Center at 1 site in Netherlands.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 17 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Netherlands. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Arterial stiffness induced by high salt diet (time frame: At week 3, week 5). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05228574, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Aug 2025.

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