Ketogenic Dietary Interventions in Autosomal Dominant Polycystic Kidney Disease (ADPKD)

Study Overview
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Brief Summary
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A mild reduction in food intake significantly inhibits renal cyst growth in mouse models of ADPKD. The underlying mechanism was unknown at the time. Recently published data show that the beneficial effect is not due to caloric restriction per se but due to the induction of the state of ketosis. Dietary interventions leading to ketosis profoundly inhibited renal cyst growth in rodent models of PKD. In addition, acute fasting led to rapid regression of renal cystic burden in mouse, rat and feline models of PKD. Due to these compelling effects in a multitude of PKD animal models, and due to the fact that well-established dietary interventions have a tremendous translational potential, KETO-ADPKD will test such interventions regimens in ADPKD patients. Two well-established ketogenic dietary regimens will be tested in comparison to a control group to address the following four questions: Feasibility: Are ketogenic dietary interventions acceptable to ADPKD patients in everyday life? Safety: Are there adverse events of ketogenic dietary interventions in ADPKD patients? Efficacy: Do the dietary interventions reach the metabolic endpoints? Do they have a short-term impact on kidney volume? Which of the two diets is the optimal approach? These questions will be addressed in an exploratory, randomized, open, single center, three-arm dietary intervention study using the following interventions in 21 ADPKD patients per treatment arm: A) Ketogenic diet B) 3-day water fasting C) Control: ad libitum food intake (no diet)

Official Title
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Ketogenic Dietary Interventions in Autosomal Dominant Polycystic Kidney Disease (ADPKD)

Conditions
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ADPKD

Intervention / Treatment
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* Other: Ketogenic diet
* Other: 3-days water-fasting
* Other: Control


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male and female ADPKD patients (based on genetics or imaging) ≥ 18 and ≤ 60 years Indicators of rapid progression, either of the following: Mayo class 1C-E (measured on screening) Truncating PKD1 mutation, onset of arterial hypertension/urological symptoms < 35 years (patient history) first- or second degree family members reaching ESRD at < 60 years of age (patient history), eGFR loss > 2.5 ml/min/yr (as determined by at least 4 serum creatinine values within the last 4 years, with at least 6 months between each measurement ), PROPKD score > 6 (patient history) CKD-stages G1-3 as determined by eGFR (CKD-EPI) Written informed consent Exclusion Criteria: Underweight or obese individuals ( as defined by BMI ≤ 18.5 kg/m2 or ≥ 35 kg/m2) Exposure to a ketogenic diet (classical ketogenic diet or modified Atkins)for more than 2 weeks within the last 6 months Participation in a weight-loss program within the last 6 months based on patient history Vegetarian / vegan lifestyle based on patient history Current treatment (or within the last 6 months) with tolvaptan or a somatostatin analogue based on patient history Inability to give informed consent Conditions prohibiting the use of a ketogenic diet (Liver damage, pancreatic failure, pyruvate-carboxylase deficiency, defects in fatty acid oxidation/gluconeogenesis/ketolysis/-neogenesis, hyperinsulinism) based on patient history Diagnosis with any disorder of fatty acid metabolism including Carnitine deficiency (primary), Carnitine palmitoyltransferase (CPT) I or II deficiency, Carnitine translocase deficiency, Beta-oxidation defects, Medium-chain acyl dehydrogenase deficiency (MCAD), Long-chain acyl dehydrogenase deficiency (LCAD), Short-chain acyl dehydrogenase deficiency (SCAD), Long-chain 3-hydroxyacyl-CoA deficiency, Medium-chain 3-hydroxyacyl-CoA deficiency, Pyruvate carboxylase deficiency based on patient history Eating disorder based on patient history (as defined by the assessment of the study physician) Alcohol abuse based on patient history (as defined by the assessment of the study physician) Type 1 diabetes mellitus based on patient history Insulin-dependent type 2 diabetes mellitus based on patient history Contraindication regarding the MRI exam e.g. non-MRI suitable implants ( including cardiac pacemakers, cochlear implants, aneurysm clip), claustrophobia, large tatoos with metal-containing ink Patients, who may be at risk from the blood loss due to scheduled blood draws at the discretion of the physician Pregnancy or breastfeeding Absence of safe contraceptive measures or non-occurrence of menopause (in women) Participation in other interventional trials Persons who are in a dependency/employment relationship with the investigators Accommodation in an institution by judicial or administrative order.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Ketogenic diet<br>Patients will follow a classical ketogenic diet for 3 month | Other: Ketogenic diet<br>* Patients will follow a classical ketogenic diet for 3 months<br>|
| Experimental: 3-days water-fasting<br>Patients will perform water fasting on 3 consecutive days within the first 14 days of each of the 3 months. | Other: 3-days water-fasting<br>* Patients will perform water fasting on 3 consecutive days within the first 14 days of each of the 3 months. In one of the 3 months they are - if required - allowed to split the 3 days into periods of 1 and 2 days. On all other days of the intervention period they are allowed to eat ad libitum.<br>|
| Placebo Comparator: Control<br>Patients are allowed to eat ad libitum | Other: Control<br>* Patients are allowed to eat ad libitum, but will be advised that low salt intake (< 5-7 g/day) and sufficient fluid intake (>3 l/day) which is considered beneficial in ADPKD.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Feasibility of ketogenic dietary interventions in every-day life, defined as a combination of objective adherence (ketone body levels) and a patient-reported feasibility questionnaire | Adherence: (A) Ketogenic diet-group: (1) ketone body levels ≥0.8 mmol/l in ≥75% of blood measurements at visits/patient or (2) ≥10 ppm in ≥75 % of Breathalyzer measurements and ketone body levels ≥0.8 mmol/l in ≥50% of blood measurements at visits/patient, to be reached by ≥ 75% of the participants by ≥50% of all per protocol measurements (B) 3-day water-fasting group:(1) full compliance to diet on ≥75% days/patient (based on diary), to be reached by ≥75% of the participants or by ≥50% of all per protocol measurements (2) at least 1 ketone body level ≥10 ppm/day on at least 2 out of 3 days of each fasting phase (analyzed using breathalyzer). Patient-reported feasibility will be measured using a dedicated feasibility questionnaire by counting the answers to the questions 1-17 and 21-26 (options ranging from-4 to+4 with higher values indicating better feasibility). Goal: Average value ≥0 in at least 75% of the participants.Both targets have to be met to reach the primary endpoint. | Day 90 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Between group-difference of the relative change in Total kidney volume | Measured by abdominal MRI (segmentation) at screening visit and after the dietary intervention (visit 5). | baseline and day 90 | 
| Between group-difference of the relative change in Body-Mass-Index (BMI) | Determination of BMI before and after dietary intervention | baseline and day 90 | 
| Between group-difference of the relative change of insulin sensitivity | Measurement of insulin-like growth factor (IGF 1), insulin and C-peptide in blood samples (measurement unit µg/l) before and after dietary intervention | baseline and day 90 | 
| Between group-difference in hsCRP | Measurement of high-sensitive CRP (hsCRP) in blood samples before and after dietary intervention | baseline and day 90 | 
| Change in quality of life assessed using the Short Form (12) Health Survey (SF-12) before and after the dietary intervention | Patients will complete a standardized quality of life questionnaire (QoL, SF-12) before and after the dietary intervention (higher values indicate better QoL, ranging from 0-100) | Baseline and day 90 | 
| Change in health-related quality of life assessed using the ADPKD-impact scale before and after the dietary intervention | Patients will complete a standardized health-related quality of life questionnaire (ADPKD-impact scale) before and after the dietary intervention (lower values indicate better HRQoL, ranging from 1-5) | Baseline and day 90 | 
| Between group-difference in blood pressure | Measurement of systolic and diastolic blood pressure before and after dietary intervention | Baseline and day 90 | 
| Incidence of Diet-related Emergent Adverse Events [Safety] at day 30, day 60, day 90 and day 120 | Occurence if Diet-related emergent adverse events will be assessed using lab values (GOT/GPT ≥ 3 times upper limit of normal, increase in serum creatinine fulfilling the KDIGO AKI criteria, triglycerides > 800 mg/dl) and incidence of renal complications (macrohematuria, flank pain, cyst infection, nephrolithiasis) | Day 30, day 60, day 90, day 120 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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ADPKD, Ketosis, dietary intervention, ketogenic diet, 3-days water fasting, fasting