Efficacy Study of Water Drinking on PKD Progression.

Study Overview
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Brief Summary
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This is a prospective 5-year study to compare the change in total kidney volume (TKV) before and after tolvaptan therapy, as the primary endpoint, in patients with ADPKD.

Detailed Description
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Tolvaptan was approved in Japan for the treatment of autosomal dominant polycystic kidney disease (ADPKD) in March 2014. This is a prospective 5-year study to compare the change in total kidney volume (TKV) before and after tolvaptan therapy, as the primary endpoint, in patients with ADPKD. Study results will be summarized, analyzed, and compiled into a research paper at 3 years (data cut-off, March 31, 2018) and at 5 years (data cut-off, March 31, 2020)

Official Title
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Efficacy Study of Long-term Water Intake on the Progression of Autosomal Dominant Polycystic Kidney Disease (ADPKD).

Conditions
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Disease Progression, Autosomal Dominant Polycystic Kidney Disease

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: The patients with ADPKD The patients who consent to the study protocol Estimated glomerular filtration rate (eGFR) or Creatinine Clearance greater than 50ml/min/1.73m2 Exclusion Criteria: Patients who might be danger to drink large amount of water such as having heart failure or past history of cerebrovascular or cardiovascular disorders. The patients who take habitual medication which affects the AVP action such as selective serotonin reuptake inhibitors (SSRI ), tricyclic antidepressants or diuretics. The patients who is considered inappropriate by physicians.

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 65 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Water Load Group<br>Water load group: 2.5   3 L water intake daily for 12 months (50ml/Kg body weight/day). When large amount water intake is not sustainable, patients can reduce the amount of water intake to the levels as much as large he or she can sustain. | |
| Non-Water Loaded Group<br>Non-water load group: The patients are free to access water intake, as they like. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total kidney volume (TKV) measured by magnetic resonance imaging (MRI). | The relationship between urine volume (and urine osmolality) and change of TKV. TKV slopes are compared between pre-study and study period. | One year (12 months) and pre-study period. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Glomerular filtration rate (GFR) estimated by plasma creatinine and cystatin C. | The relationship between urine volume (and urine osmolality) and change of GFR. | One year (12 months) | 
| Plasma arginine vasopressin (AVP, Copeptin) level. | The relationship between urine volume (osmolality) and plasma AVP. | 4-8-12 months | 
| Quality of life (QOL) questionnaire. | The relationship between QOL and urine volume. | 4-8-12 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Autosomal Dominant Polycystic Kidney Disease., Arginine vasopressin, Total Kidney Volume, Glomerular Filtration Rate