Di-PKD: A Pilot Trial of Dietary Intervention in Patients With Autosomal Dominant Polycystic Kidney Disease

Not Applicable

Not yet recruiting

• Conditions: Autosomal Dominant Polycystic Kidney Disease (ADPKD)

• Registration Number: NCT06786260
• Lead Sponsor: Loma Linda University

Brief Summary

The goal of this interventional study is to evaluate the impact of a specific diet (low salt, limited caffeine, high potassium, low phosphate, limited protein, limited carbohydrate intake, adequate water intake) on changes in serum and urinary biomarkers, total kidney volume (TKV), and cyst progression in subjects with autosomal dominant polycystic kidney disease (ADPKD).

Researchers will compare the results of subjects in the study diet (interventional) arm to the results of subjects in the regular diet (control) arm.

Detailed Description

15 subjects will be enrolled in each dietary arm for a total of 30 subjects. All subjects will follow the study diet for one week, after which serum and urinary biomarkers will be measured. A baseline evaluation, including genetic testing, MRI, Mayo Clinic Imaging Classification and 10-question survey will also be conducted. After Week 1 of the study, subjects will be assigned to the intervention or control arm. Subjects will have six follow-up visits at months 1, 2, 3, 6, 9 and 12 to assess adherence to diet. Serum and urinary biomarkers will be repeated at each visit. MRI will be repeated at Month 12.

Study Timeline

• Status Verified: 2025-01
• Study First Submitted: 2025-01-10
• Study First Submitted QC: 2025-01-15
• Last Update Submitted: 2025-01-15
• Study First Posted: 2025-01-22
• Last Update Posted: 2025-01-22
• Study Start: 2025-07
• Primary Completion: 2026-07
• Study Completion: 2026-12

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 30

Inclusion Criteria

• Confirmed diagnosis of ADPKD
• Genetic testing confirmation of PKD1 or PKD2
• eGFR >30mL/1.73m2
• 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

• History of dietary non-adherence
• Subjects on Tolvaptan
• Comorbidities that could interfere with participation (Diabetes, Heart Failure (EF<30%) Advanced Chronic Kidney Disease (CKD) Stage 4 and higher)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Progression of kidney cysts by change in total kidney volume (TKV) from baseline to 12 months	Change between baseline and 12 months	A composite measurement of MRI to determine total kidney volume (TKV) by kidney length, width, and depth will be done at baseline and again at 12 months. MRI results will be compared between the two-time points to assess the cyst progression, if any. An increase of about 5% per year from baseline will be significant.

Secondary Outcome Measures

Name	Time	Method
Progression of kidney cysts as evidenced by urinary biomarkers from baseline to 12 months	Change between baseline and 12 months	A urine sample will be collected at the end of the preconditioning week to establish a baseline for the urinary biomarkers cAMP and MCP-1. This is a composite measurement. Values for cAMP and MCP-1 at 12 months will be compared to the baseline values. If the values at 12 months remain the same or less than the composite baseline values, this will indicate a low likelihood that the kidney cysts have progressed. A significant change of 20% or greater overall in the combined biomarkers will indicate a kidney cyst progression.
Progression of kidney cysts as evidenced by serum biomarkers from baseline to 12 months	Change between baseline and 12 months	A blood draw will be performed at the end of the preconditioning week to establish a baseline for the serum biomarkers uric acid, ADH, FGF-23, bicarbonate, and cystatin C. This is a composite measurement. Values for uric acid, ADH, FGF-23, bicarbonate, and cystatin C at 12 months will be compared to the baseline values. If the values at 12 months remain the same or less than the composite baseline values, this will indicate a low likelihood that the kidney cysts have progressed. A significant change of 20% or greater overall in the combined biomarkers will indicate a kidney cyst progression.

Trial Locations

Locations (1)

Loma Linda University Health; 🇺🇸 Loma Linda, California, United States