An interventional study of Carbohydrate Restricted, Plant Dominant Diet and usual diet in Autosomal Dominant Polycystic Kidney Disease (ADPKD), sponsored by Assaf-Harofeh Medical Center. Not yet recruiting. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-06-26.
Sponsored by Assaf-Harofeh Medical Center · Not applicable, Interventional, and Basic science
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.
Exclusion Criteria:
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 · Behavioral: usual diet
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 · Behavioral: usual 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.
Participants continue their habitual diet without specific dietary intervention or structured nutritional guidance.
Change in Urinary MCP-1/Creatinine Ratio
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.
Time frame: Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Association Between Carbohydrate Intake and MCP-1
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.
Time frame: Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Association Between Change in HOMA-IR and MCP-1
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.
Time frame: Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Dietary Adherence and MCP-1 Response
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.
Time frame: Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Change in Metabolic and Biochemical Parameters (Safety Outcomes)
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.
Time frame: Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Mediation Analysis of Insulin Resistance and MCP-1
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.
Time frame: Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Gene Expression of CPT1A and ACOX1
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.
Time frame: Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Exploratory Analysis of the Gut Microbiome
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.
Time frame: Baseline and End of each 12-week study period (weeks 0,12, 18 and 30)
Health-Related Quality of Life (SF-36)
Pre-specified exploratory assessment of health-related quality of life using the Short Form-36 (SF-36) questionnaire.
Time frame: Baseline and end of each 12-week study period (Weeks 0, 12, 18, and 30)
No study locations are listed for this record.
Plan to share: Undecided
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Polycystic Kidney, Autosomal Dominant→
Assaf-Harofeh Medical Center