Dietary Intervention for Polycystic Kidney Disease

(ADPKD Trial)

Overseen By Sayna Norouzi, MD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Loma Linda University

Must not be taking: Tolvaptan

Disqualifiers: Diabetes, Heart failure, Advanced CKD, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 7

Duration: 12 months

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a specific diet to assess its effects on individuals with polycystic kidney disease (ADPKD), a condition that causes cysts to form in the kidneys. Researchers aim to determine if a low salt, low caffeine, high potassium, low phosphate, and limited protein and carbohydrate diet (referred to as the Interventional Diet) can help manage the disease by examining changes in kidney size and certain body markers. Participants will be divided into two groups: one will follow the special diet, while the other will maintain their regular diet. This trial suits individuals with a confirmed ADPKD diagnosis who are willing to adhere to the study diet for a year. As an unphased trial, it offers a unique opportunity to contribute to understanding dietary impacts on ADPKD management.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but you cannot participate if you are taking Tolvaptan.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that dietary changes can help manage polycystic kidney disease (PKD). One study found that reducing salt and caffeine intake while increasing foods high in potassium can slow the disease's progression.

Many participants reported that the diet was easy to follow. In another study, most participants adhered to it, with some experiencing body fat loss and reduced liver size, indicating additional health benefits.

Overall, these findings suggest the diet is manageable. No major side effects were reported in these studies, making it a potentially safe option for people with PKD. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the dietary intervention for Polycystic Kidney Disease (PKD) because it offers a non-pharmaceutical approach to managing the condition. Unlike typical treatments that focus on controlling symptoms with medications like antihypertensives or vasopressin receptor antagonists, this approach uses a specific diet plan to potentially slow disease progression. The diet emphasizes low salt, limited caffeine, high potassium, low phosphate, and moderated protein and carbohydrate intake, along with adequate water consumption. This dietary strategy could provide a holistic way to manage PKD, potentially reducing reliance on medication and its associated side effects.

What evidence suggests that this dietary intervention is effective for polycystic kidney disease?

Research has shown that dietary changes can help manage polycystic kidney disease (ADPKD). In this trial, participants in the interventional diet arm will follow a specified diet that includes reducing salt and caffeine intake, increasing potassium, and decreasing phosphate. Previous studies have demonstrated that these specific dietary changes can noticeably reduce cyst growth and improve overall health. Some individuals have also experienced lower blood pressure and improved insulin levels, both beneficial for kidney function. Overall, these dietary changes have shown promising results for those with ADPKD. ^{1 2 5 6 7}

Who Is on the Research Team?

Amir Abdipour, MD

Principal Investigator

Loma Linda University Health

Are You a Good Fit for This Trial?

This trial is for people with autosomal dominant polycystic kidney disease (ADPKD). Participants should be willing to follow a specific diet plan. The exact eligibility criteria are not provided, but typically include factors like age range, stage of the disease, and overall health status.

Inclusion Criteria

I have been diagnosed with ADPKD.

Willingness to adhere to a preconditioning diet for 1 week and ability to complete the study

Mayo Clinic Imaging Classification (MCIC): 1C, 1D, 1E

Exclusion Criteria

I do not have severe diabetes, heart failure, or advanced kidney disease.

History of dietary non-adherence

I am currently taking Tolvaptan.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Preconditioning

All subjects follow the study diet for one week, after which serum and urinary biomarkers are measured

1 week

1 visit (in-person)

Treatment

Subjects follow either the interventional or regular diet for 12 months with follow-up visits to assess adherence and measure biomarkers

12 months

6 visits (in-person) at months 1, 2, 3, 6, 9, and 12

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Interventional Diet

Trial Overview

The study tests how a special diet affects ADPKD. This diet includes low salt, limited caffeine and protein, high potassium, low phosphate, controlled carbs, and proper water intake. Researchers will compare changes in biomarkers and kidney size between those on this diet versus a regular diet.

How Is the Trial Designed?

Group I: Interventional Diet Experimental Treatment 1 Intervention

Subjects will follow a specified diet (low salt, limited caffeine, high potassium, low phosphate, and limited protein and carbohydrate intake along with adequate water intake) after 1 week of preconditioning for 12 months.

Group II: Regular Diet Active Control 1 Intervention

Subjects will follow the diet they normally adhere to after 1 week of preconditioning.

Who Is Running the Clinical Trial?

Loma Linda University

Lead Sponsor

Trials

322

Recruited

267,000+

Published Research Related to This Trial

Recent evidence suggests that specific dietary regimens, such as caloric restriction, intermittent fasting, and ketogenic diets, may help slow the progression of autosomal dominant polycystic kidney disease (ADPKD) by influencing nutrient signaling in the kidneys.

The review highlights the potential for these dietary interventions to not only impact kidney health but also provide systemic metabolic benefits, with ongoing human clinical trials expected to provide further insights.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dietary Interventions in Autosomal Dominant Polycystic Kidney Disease. Pickel, L., Iliuta, IA., Scholey, J., et al.[2023]

In a study using a murine model of polycystic kidney disease (PKD), early dietary protein restriction significantly reduced cyst growth, with low protein diets leading to an 11% lower percentage of cyst area and a 46% lower total cyst area compared to normal protein diets.

The type of dietary oil (sunflower seed oil vs. fish oil) did not affect disease progression, suggesting that the amount of protein in the diet is more critical for managing PKD than the type of fat consumed.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of dietary protein restriction and oil type on the early progression of murine polycystic kidney disease. Aukema, HM., Ogborn, MR., Tomobe, K., et al.[2019]

Food restriction (FR) in mouse models of autosomal dominant polycystic kidney disease (ADPKD) significantly slows disease progression by reducing cyst area, renal fibrosis, inflammation, and injury in a dose-dependent manner.

The beneficial effects of FR are linked to the suppression of the mTOR pathway and activation of the LKB1/AMPK pathway, suggesting that dietary interventions could be a novel therapeutic approach for managing ADPKD in patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Food Restriction Ameliorates the Development of Polycystic Kidney Disease. Warner, G., Hein, KZ., Nin, V., et al.[2018]

Recent research highlights the potential of dietary modifications as a strategy to prevent or slow the progression of polycystic kidney disease (PKD), alongside emerging drug treatments like vasopressin-receptor agonists.

The review summarizes current evidence on how specific nutrients and dietary patterns may influence cyst growth and disease progression in PKD, suggesting that evidence-based dietary interventions could play a significant role in managing the condition.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Diet and Polycystic Kidney Disease: Nutrients, Foods, Dietary Patterns, and Implications for Practice. Lambert, K., Gardos, R., Coolican, H., et al.[2023]

Citations

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pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC11108253/

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Dietary interventions such as caloric restriction, intermittent fasting, and ketogenic diet hold promise in ADPKD management by enhancing metabolic health.

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Dietary interventions for polycystic kidney disease yield an ' ...

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Feasibility and impact of ketogenic dietary interventions in ...

Ninety-five percent (KD) and 85% (WF) report the diet as feasible. KD leads to significant reductions in body fat and liver volume. Additionally ...

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sciencedirect.com

sciencedirect.com/science/article/pii/S2161831322000825

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Clinical trials of TRF showed similar improvements; decreased blood pressure (67) and insulin resistance and oxidative stress (68) have been observed in healthy ...

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sciencedirect.com

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Nutrition - Polycystic kidney disease

High blood pressure in PKD doesn't seem to be caused by salt intake. Regardless, excessive amounts of salt should be avoided and lowering dietary salt may help ...