Dietary Modulation of Urinary MCP-1 in ADPKD

June 13, 2026 updated by: Elad Nizri, Assaf-Harofeh Medical Center

Open Labeled , Randomized, Controlled, Crossover Trial on the Effect of a Carbohydrate Restricted Plant Dominant Diet on MCP-1 Mediated Inflammatory Signaling in Autosomal Dominant Polycystic Kidney Disease

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by progressive cyst growth and declining kidney function. Inflammatory pathways, including those mediated by monocyte chemoattractant protein-1 (MCP-1), are increasingly recognized as contributors to disease progression. Metabolic alterations in cystic epithelial cells may influence inflammatory signaling, suggesting a potential role for dietary interventions targeting metabolic pathways.

This study is a prospective, randomized, open-label crossover trial designed to evaluate the effect of a carbohydrate restricted, plant dominant dietary intervention on urinary MCP-1 levels in adults with ADPKD. Participants will be randomized to one of two sequences: dietary intervention followed by usual diet, or usual diet followed by dietary intervention, with a washout period between study phases. Each study period will last 12 weeks.

The primary objective is to assess within subject differences in urinary MCP-1/creatinine ratio between the dietary intervention and usual diet conditions. Secondary outcomes include measures of metabolic parameters, insulin resistance, dietary adherence, and safety.

This study aims to explore whether a structured dietary approach may influence intrarenal inflammatory activity in ADPKD and provide preliminary data to inform future interventional studies.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

36

Phase

  • 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 Contact

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

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Age ≥18
  2. Diagnosis of ADPKD based on established clinical or genetic criteria (PKD 1/PKD2)
  3. Estimated glomerular filtration rate (eGFR) between 45 and 90 mL/min/1.73 m²
  4. Mayo Imaging Classification class 1C-1E based on MRI-derived height-adjusted total kidney volume.
  5. Stable kidney function, defined as no acute kidney injury and no decline in eGFR >20% within the preceding 3 months
  6. Stable antihypertensive and chronic medications for at least 4 weeks prior to enrollment
  7. Ability and willingness to adhere to the prescribed dietary intervention
  8. Ability to provide written informed consent

Exclusion Criteria:

  1. eGFR <45 mL/min/1.73 m² or requirement for dialysis
  2. History of kidney transplantation
  3. Significant albuminuria, defined as urine albumin to creatinine ratio (UACR) >300 mg/g
  4. Poorly controlled or unstable diabetes mellitus (e.g., HbA1c >8% or clinically significant glycemic variability or frequent hypoglycemia)
  5. Use of Tolvaptan at the time of screening or within the study period
  6. Current adherence to a ketogenic or carbohydrate restricted diet
  7. Unintentional weight loss >5% within the preceding 3 months
  8. Active infection, inflammatory disease, or malignancy that may influence inflammatory markers
  9. Current use of systemic corticosteroids or immunosuppressive therapy
  10. Active or symptomatic nephrolithiasis
  11. Serum bicarbonate <20 mmol/L
  12. Pregnancy or breastfeeding
  13. Known eating disorder or condition limiting adherence to dietary interventions
  14. Participation in another interventional study within the previous 3 months
  15. Any condition that, in the opinion of the investigators, would interfere with study participation or interpretation of results

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: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Sequence A: Dietary Intervention → Usual Diet
Participants receive a carbohydrate restricted, plant dominant diet for 12 weeks, followed by a washout period and then usual diet for 12 weeks.
Behavioral: Carbohydrate Restricted, Plant Dominant Diet
A structured dietary intervention targeting approximately 20% of total daily energy intake from carbohydrates (range 15-25%), with a plant dominant composition. Energy and protein intake are prescribed based on adjusted body weight. The intervention is not ketogenic and is not intended to induce nutritional ketosis. Participants receive individualized dietary counseling and ongoing support from a registered dietitian.
Behavioral: usual diet
Participants continue their habitual diet without specific dietary intervention or structured nutritional guidance.
Experimental: Sequence B: Usual Diet → Dietary Intervention
Participants follow their usual diet for 12 weeks, followed by a washout period and then the dietary intervention for 12 weeks.
Behavioral: Carbohydrate Restricted, Plant Dominant Diet
A structured dietary intervention targeting approximately 20% of total daily energy intake from carbohydrates (range 15-25%), with a plant dominant composition. Energy and protein intake are prescribed based on adjusted body weight. The intervention is not ketogenic and is not intended to induce nutritional ketosis. Participants receive individualized dietary counseling and ongoing support from a registered dietitian.
Behavioral: usual diet
Participants continue their habitual diet without specific dietary intervention or structured nutritional guidance.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Urinary MCP-1/Creatinine Ratio
Time Frame: Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Urinary MCP-1 levels will be measured in first morning urine samples and normalized to urine creatinine (MCP-1/creatinine ratio). For each study period, two samples will be collected within the final week (2-5 days apart), and the mean value will be used. The primary outcome is the within subject difference in MCP-1/creatinine ratio between the dietary intervention and usual diet conditions.
Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Association Between Carbohydrate Intake and MCP-1
Time Frame: Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Mean carbohydrate intake during each study period will be calculated from repeated dietary assessments. The association between carbohydrate intake and urinary MCP-1/creatinine ratio will be evaluated to explore a potential dose response relationship.
Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Association Between Change in HOMA-IR and MCP-1
Time Frame: Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
The association between changes in insulin resistance (HOMA-IR) and changes in urinary MCP-1/creatinine ratio will be evaluated within individuals across study conditions.
Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Dietary Adherence and MCP-1 Response
Time Frame: Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Dietary adherence will be defined as the proportion of dietary assessments in which carbohydrate intake falls within the target range (15-25% of total energy intake). The association between adherence and urinary MCP-1/creatinine ratio will be evaluated.
Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Change in Metabolic and Biochemical Parameters (Safety Outcomes)
Time Frame: Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Changes in selected metabolic and biochemical parameters, including serum bicarbonate, LDL cholesterol, and estimated glomerular filtration rate (eGFR), will be assessed between study conditions to evaluate the safety of the dietary intervention.
Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Mediation Analysis of Insulin Resistance and MCP-1
Time Frame: Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Exploratory analysis to evaluate whether changes in insulin resistance (HOMA-IR) mediate the relationship between dietary intervention and urinary MCP-1/creatinine ratio using regression based mediation models.
Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Gene Expression of CPT1A and ACOX1
Time Frame: Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Pre-specified exploratory analysis of gene expression of CPT1A and ACOX1, key regulators of fatty acid oxidation pathways, measured in peripheral blood samples. Expression levels will be evaluated in relation to dietary intervention and changes in urinary MCP-1/creatinine ratio.
Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Exploratory Analysis of the Gut Microbiome
Time Frame: Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Exploratory analyses will evaluate changes in gut microbial composition associated with the dietary intervention. Stool samples collected at baseline and at the end of each study period will undergo microbiome analysis. Changes in microbial diversity and taxonomic composition will be explored and correlated with dietary adherence, urinary MCP-1 levels, and metabolic parameters. Given the exploratory nature of these analyses and the limited sample size, findings will be considered hypothesis-generating.
Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)

Collaborators and Investigators

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

Sponsor

Assaf-Harofeh Medical Center

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

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 (Estimated)

July 10, 2026

Primary Completion (Estimated)

January 1, 2029

Study Completion (Estimated)

January 1, 2029

Study Registration Dates

First Submitted

June 9, 2026

First Submitted That Met QC Criteria

June 13, 2026

First Posted (Actual)

June 16, 2026

Study Record Updates

Last Update Posted (Actual)

June 16, 2026

Last Update Submitted That Met QC Criteria

June 13, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 0090-26-ASF

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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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