DRINK: High Water Intake in Polycystic Kidney Disease

Sponsor

Cambridge University Hospitals NHS Foundation Trust (Other)

Overall Status

Completed

CT.gov ID

NCT02933268

Collaborator

PKD Charity (Other), Addenbrookes Charitable Trust (Other), British Renal Society & British Kidney Patient Association (Other)

Enrollment

Location

Arms

22.1

Actual Duration (Months)

1.9

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

DRINK is an open-label randomised controlled feasibility trial of high versus ad libitum water intake in ADPKD.

Condition or Disease	Intervention/Treatment	Phase
Autosomal Dominant Polycystic Kidney Disease	Dietary Supplement: High water intake Other: Ad libitum water intake	N/A

Detailed Description

Autosomal Dominant Polycystic Kidney Disease (PKD) affects 12.5 million people worldwide, and accounts for 7% of those requiring renal replacement therapy. The hormone vasopressin drives cyst growth until ultimately most of the normal functioning kidney tissue is replaced and compressed by cysts over the life course. Half of those affected will require dialysis by the age of 55 years.

Vasopressin blockade has emerged as a viable strategy for altering disease course. High water intake suppresses vasopressin, and may therefore slow cyst growth and consequent disease progression. However, evidence to support high water intake in PKD is lacking, and it is not clear whether patients can adhere sufficiently to a high water intake.

DRINK is a single-centre prospective, open label, parallel group randomised controlled feasibility trial. The primary objective is to establish whether a definitive large randomised trial comparing high versus ad libitum water intake on long-term disease progression is deliverable. Fifty patients will be recruited from the Renal Genetics service at Addenbrooke's Hospital. Participants will be randomly allocated to the high water intake (high) or the ad libitum (standard) water intake group. For the high intake group the aim is to drink large enough volumes of water to achieve and maintain dilute urine (urine osmolality < 270 mOsmo/kg or urine specific gravity ≤ 1.010 ). Multiple methods will be employed to promote adherence these include instruction and education as well as self-monitoring of urine specific gravity twice weekly by participants and the recording of results via a trial specific smartphone application.

Study Design

Study Type:

Interventional

Actual Enrollment :

42 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

None (Open Label)

Primary Purpose:

Treatment

Official Title:

Determining Feasibility of Randomisation to High vs ad Libitum Water Intake in Polycystic Kidney Disease: The DRINK Randomised Feasibility Trial

Actual Study Start Date :

Sep 26, 2016

Actual Primary Completion Date :

Mar 31, 2018

Actual Study Completion Date :

Jul 31, 2018

Arms and Interventions

Arm	Intervention/Treatment
Active Comparator: Ad libitum water intake Ad libitum water intake, defined as intake guided by thirst to achieve a target urine osmolality > 300 mOsmo/kg	Other: Ad libitum water intake Water intake guided by thirst
Active Comparator: High water intake Personalised daily water intake prescription to achieve target urine osmolality < 270 mOsm/kg.	Dietary Supplement: High water intake High water intake aimed at achieving an urine osmolality < 270mOsmo/kg. Individualised prescription for each participant based on the free water clearance formula calculation.

Arm

Intervention/Treatment

Active Comparator: Ad libitum water intake

Ad libitum water intake, defined as intake guided by thirst to achieve a target urine osmolality > 300 mOsmo/kg

Other: Ad libitum water intake

Water intake guided by thirst

Active Comparator: High water intake

Personalised daily water intake prescription to achieve target urine osmolality < 270 mOsm/kg.

Dietary Supplement: High water intake

High water intake aimed at achieving an urine osmolality < 270mOsmo/kg. Individualised prescription for each participant based on the free water clearance formula calculation.

Outcome Measures

Primary Outcome Measures

The proportion of patients achieving a urine osmolality < 270 mOsm/kg [8 weeks]

Secondary Outcome Measures

Urine osmolality [8 weeks]
Achieved urine osmolality as a surrogate for vasopressin suppression
Proportion of participants that can self-monitor and report urine specific gravity reliably [8 weeks]
Proportion of patients experiencing a serious adverse event [12 weeks]
Acute change in estimated GFR [4 weeks]
Evaluation of the change form baseline eGFR after 2 weeks
Health-Related Quality of Life (HRQoL) [12 weeks]
Change from baseline HRQoL as estimated by EQ5D-5L
Recruitment rate [8 weeks]

Eligibility Criteria

Criteria

Ages Eligible for Study:

16 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

Have given written informed consent to participate
Aged 16 years or older
Have a diagnosis of ADPKD (fulfilling radiological diagnostic criteria ± genetic evidence)
eGFR ≥ 20ml/min/1.73m2
Able to self-monitor urine SG

Exclusion Criteria:

Inability to provide informed consent
eGFR < 20ml/min/1.73m2
Fluid overload states e.g. heart failure, cirrhosis, or requirement for fluid restriction
Confounding illness impacting on renal disease e.g. concomitant diabetes or glomerulonephritis
Treatment with diuretics for fluid overload (those on diuretics for hypertension may participate in the trial after a run-in period of 2 weeks)
Treatment with Tolvaptan in the last 4 weeks
Pregnancy or breastfeeding