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The Effect of High and Low Sodium Intake on Urinary Aquaporin-2 in Autosomal Dominant Polycystic Kidney Disease

Primary Purpose

Polycystic Kidney, Autosomal Dominant

Status
Completed
Phase
Not Applicable
Locations
Denmark
Study Type
Interventional
Intervention
High Sodium Diet
Low Sodium Diet
Hypertonic saline infusion
Sponsored by
Carolina Cannillo
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional other trial for Polycystic Kidney, Autosomal Dominant focused on measuring ADPKD, Urinary Aquaporin-2, ENaC, Fractional sodium excretion, High/low sodium diet

Eligibility Criteria

18 Years - 65 Years (Adult, Older Adult)All SexesAccepts Healthy Volunteers

Inclusion Criteria:

  • Caucasian men and women
  • age 18-65 years
  • BMI between 18,5-30,0 kg/m2
  • ADPKD, diagnosed by the following findings on ultra scan:

    • for patients without ADPKD family history: > 5 bilateral cysts
    • for patients with ADPKD family history: < 30 years: 2 cysts (unilateral or bilateral) 30-60 years: 2 or more bilateral cysts > 60 years: 4 or more bilateral cysts
  • Kidney function: stadium 1-4.

Exclusion Criteria:

  • Other kidney disease
  • Anamnestic or clinical signs of acute myocardial infarction, atrial fibrillation, heart valve disease or chronic heart failure
  • Anamnestic or clinical signs of disease in lungs, liver,endocrine organs or brain or neoplastic disease
  • Family history of rupture of intracerebral aneurisms
  • Alcohol or drug abuse
  • Smoking
  • Medical treatment arat form antihypertensives and oral anticonceptives
  • Pregnancy or breastfeeding

Sites / Locations

  • Department of Medical Research, Holstebro Hospital

Arms of the Study

Arm 1

Arm 2

Arm 3

Arm 4

Arm Type

Other

Other

Other

Other

Arm Label

Patients with ADPKD, HS

Patients with ADPKD, LS

Healthy Control Subjects, HS

Healthy Control Subjects, LS

Arm Description

Each subject was studied on 2 separate days at least 3 weeks apart. During 4 days before the study day, the subjects consumed either a high sodium diet or a low sodium diet in randomized order (HS-LS/ LS-HS). On the study day a hypertonic saline infusion was given.

Each subject was studied on 2 separate days at least 3 weeks apart. During 4 days before the study day, the subjects consumed either a high sodium diet or a low sodium diet in randomized order (HS-LS/ LS-HS). On the study day a hypertonic saline infusion was given.

Each subject was studied on 2 separate days at least 3 weeks apart. During 4 days before the study day, the subjects consumed either a high sodium diet or a low sodium diet in randomized order (HS-LS/ LS-HS). On the study day a hypertonic saline infusion was given.

Each subject was studied on 2 separate days at least 3 weeks apart. During 4 days before the study day, the subjects consumed either a high sodium diet or a low sodium diet in randomized order (HS-LS/ LS-HS). On the study day a hypertonic saline infusion was given.

Outcomes

Primary Outcome Measures

u-AQP-2CR
Urinary Aquaporin-2 corrected for creatinine

Secondary Outcome Measures

u-ENaC (beta)CR
Urinary ENaC (beta) corrected for creatinine
FENa
fractional sodium excretion
CH2O
Free water excretion
u-cAMP
urinary excretion of cAMP
uPGE-2
urinary excretion of PGE-2
GFR
glomerular filtration rate
p-vasopressin
plasma concentration of vasopressin
p-aldosterone.
plasma concentration of aldosterone

Full Information

First Posted
December 10, 2006
Last Updated
March 16, 2018
Sponsor
Carolina Cannillo
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1. Study Identification

Unique Protocol Identification Number
NCT00410007
Brief Title
The Effect of High and Low Sodium Intake on Urinary Aquaporin-2 in Autosomal Dominant Polycystic Kidney Disease
Official Title
The Effect of High and Low Sodium Intake on Urinary Aquaporin-2 in Autosomal Dominant Polycystic Kidney Disease, During Basal Conditions and After Hypertonic Saline Infusion.
Study Type
Interventional

2. Study Status

Record Verification Date
March 2018
Overall Recruitment Status
Completed
Study Start Date
October 2006 (undefined)
Primary Completion Date
October 2010 (Actual)
Study Completion Date
November 2011 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Sponsor-Investigator
Name of the Sponsor
Carolina Cannillo

4. Oversight

Data Monitoring Committee
No

5. Study Description

Brief Summary
The aim of the study is to test the following hypotheses: that the function and/or regulation of AQP2 and /or ENaC in the principal cells is abnormal in autosomal dominant polycystic kidney disease. if an abnormal function of the principal cells is present in autosomal dominant polycystic kidney disease, this will become more pronounced at high and low sodium intake.
Detailed Description
Recruitment: The patients with ADPKD are recruited from the Outpatient Nephrology Clinic of the Department of Medicine, Holstebro Hospital (Holstebro, Denmark). The control subjects are recruited by advertising in public institutions and private companies. Number of Subjects: A difference in u-AQP2CR of 40 ng/mmol is considered the minimal relevant difference. A sample size of 10 subjects, who can be evaluated, has 80% power to detect this difference assuming a level of significance of 5% and an SD of 30 ng/mmol. Because a few subjects are expected to drop out, 14-15 subjects will be included in each group. Experimental Procedure Before the Study Day: Five days before the study day, the subjects collect a standardized, HS (300 mmol sodium/day/17.5 g salt/day) or LS (30 mmol sodium/day/1.8 g salt/day), 4-day diet from the hospital kitchen. Depending on the individually estimated energy requirement, the participants are given either a diet of 8,000 or 11,000 kJ/day. The energy distribution is 55% carbohydrates, 15% proteins, and 30% lipids. The 4-day diet is started the following morning. The fluid intake is also standardized during the 4 days. The subjects are asked to drink exactly 250 ml/1,000 kJ/day and to abstain from coffee, tea, and alcoholic beverages. The subjects are instructed to keep their physical activity unchanged during the two experiments and to abstain from hard training. The subjects have to collect their urine for 24 h the day before the study day. Experimental Procedure on the Study Day: On the study day, the subjects are asked to drink 175 ml of water every 30 min from 7:00 AM. The subjects arrive at the department at 8:00 AM. Peripheral iv lines are inserted into the antecubital veins of both forearms, one for infusion of 51Cr-EDTA and hypertonic saline, and one for withdrawal of blood samples. The subjects will be kept in the supine position from 8:00 AM to 1:30 PM except during voiding, which will take place in the sitting or standing position. At 8:30 AM, a priming dose of 51Cr-EDTA is administered, followed by sustained infusion. After 60 min of equilibration, the study will continue with five clearance periods, the first two of 30-min duration (P1-P2), the last three of 60-min duration (P3-P5). The first two clearance periods are baseline periods. At 10:30 AM, 7 ml/kg of 3% saline is given over 30 min. Blood pressure and heart rate are measured every 30 min from 9:30 AM to 1:30 PM. Urine is collected in each clearance period and analyzed for sodium, osmolality, u-AQP2, u-ENaC-betaCR, u-cAMP, u-PGE2, and 51CrEDTA. Blood samples will be drawn every 30 min from 9:30 AM to 10:30 AM and every hour from 11:30 AM to 1:30 PM, and will be analyzed for sodium, osmolality, and 51Cr-EDTA. In addition, analysis of p-AVP, p-Renin, p-ANG II, p-Aldo, p-ANP, and p-BNP will be performed from blood samples drawn at 10:30 AM, 11:30 AM, 12:30 PM, and 1:30 PM. Statistics: Statistical analyses will be performed using SPSS version 15 (SPSS, Chicago, IL). Single baseline values are obtained by taking the weighted average of the measurements from the two baseline periods. The baseline values of the two groups will be compared by Student's t-test. The baseline values during HS and LS intake will be compared by paired samples t-tests. The investigators will use the "General Linear Model Repeated Measures" procedure in SPSS with time as the within-subject factor and group as the between-subject factor to compare the effect variables in patients and controls. The changes in response to the hypertonic saline infusion in each group will be analyzed with the General Linear Model Repeated Measures procedure with time as the within-subject factor and paired samples t-tests with Bonferroni correction as post hoc tests. P values Recruitment The patients with ADPKD will be recruited from the Outpatient Nephrology Clinic of the Department of Medicine, Holstebro Hospital (Holstebro, Denmark). The control subjects will be recruited by advertising in public institutions and private companies. Number of Subjects A difference in u-AQP2CR of 40 ng/mmol is considered the minimal relevant difference. A sample size of 10 subjects, who could be evaluated, has 80% power to detect this difference assuming a level of significance of 5% and an SD of 30 ng/mmol. Because a few subjects are expected to drop out, 14-15 subjects will be included in each group. Experimental Procedure Before the Study Day Five days before the study day, the subjects will collect a standardized, HS (300 mmol sodium/day/17.5 g salt/day) or LS (30 mmol sodium/day/1.8 g salt/day), 4-day diet from the hospital kitchen. Depending on the individually estimated energy requirement, the participants will be given either a diet of 8,000 or 11,000 kJ/day. The energy distribution will be 55% carbohydrates, 15% proteins, and 30% lipids. The 4-day diet will start the following morning. The fluid intake is also standardized during the 4 days. The subjects are asked to drink exactly 250 ml/1,000 kJ/day and to abstain from coffee, tea, and alcoholic beverages. The subjects will be instructed to keep their physical activity unchanged during the two experiments and to abstain from hard training. The subjects have to collect their urine for 24 h the day before the study day. Experimental Procedure on the Study Day On the study day, the subjects are asked to drink 175 ml of water every 30 min from 7:00 AM. The subjects arrive at the department at 8:00 AM. Peripheral iv lines will be inserted into the antecubital veins of both forearms, one for infusion of 51Cr-EDTA and hypertonic saline, and one for withdrawal of blood samples. The subjects will be kept in the supine position from 8:00 AM to 1:30 PM except during voiding, which will take place in the sitting or standing position. At 8:30 AM, a priming dose of 51Cr-EDTA is administered, followed by sustained infusion. After 60 min of equilibration, the study will continue with five clearance periods, the first two of 30-min duration (P1-P2), the last three of 60-min duration (P3-P5). The first two clearance periods are baseline periods. At 10:30 AM, 7 ml/kg of 3% saline is given over 30 min. Blood pressure and heart rate will be measured every 30 min from 9:30 AM to 1:30 PM. Urine is collected in each clearance period and analyzed for sodium, osmolality, u-AQP2, u-ENaC-betaCR, u-cAMP, u-PGE2, and 51CrEDTA. Blood samples will be drawn every 30 min from 9:30 AM to 10:30 AM and every hour from 11:30 AM to 1:30 PM, and will be analyzed for sodium, osmolality, and 51Cr-EDTA. In addition, analysis of p-AVP, p-Renin, p-ANG II, p-Aldo, p-ANP, and p-BNP will be performed from blood samples drawn at 10:30 AM, 11:30 AM, 12:30 PM, and 1:30 PM. Statistics Statistical analyses will be performed using SPSS version 15 (SPSS, Chicago, IL). Single baseline values are obtained by taking the weighted average of the measurements from the two baseline periods. The baseline values of the two groups will be compared by Student's t-test. The baseline values during HS and LS intake will be compared by paired samples t-tests. The investigators will use the "General Linear Model Repeated Measures" procedure in SPSS with time as the within-subject factor and group as the between-subject factor to compare the effect variables in patients and controls. The changes in response to the hypertonic saline infusion in each group will be analyzed with the General Linear Model Repeated Measures procedure with time as the within-subject factor and paired samples t-tests with Bonferroni correction as post hoc tests. P values ≤0.05 will be considered significant.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Polycystic Kidney, Autosomal Dominant
Keywords
ADPKD, Urinary Aquaporin-2, ENaC, Fractional sodium excretion, High/low sodium diet

7. Study Design

Primary Purpose
Other
Study Phase
Not Applicable
Interventional Study Model
Crossover Assignment
Masking
ParticipantInvestigator
Allocation
Randomized
Enrollment
29 (Actual)

8. Arms, Groups, and Interventions

Arm Title
Patients with ADPKD, HS
Arm Type
Other
Arm Description
Each subject was studied on 2 separate days at least 3 weeks apart. During 4 days before the study day, the subjects consumed either a high sodium diet or a low sodium diet in randomized order (HS-LS/ LS-HS). On the study day a hypertonic saline infusion was given.
Arm Title
Patients with ADPKD, LS
Arm Type
Other
Arm Description
Each subject was studied on 2 separate days at least 3 weeks apart. During 4 days before the study day, the subjects consumed either a high sodium diet or a low sodium diet in randomized order (HS-LS/ LS-HS). On the study day a hypertonic saline infusion was given.
Arm Title
Healthy Control Subjects, HS
Arm Type
Other
Arm Description
Each subject was studied on 2 separate days at least 3 weeks apart. During 4 days before the study day, the subjects consumed either a high sodium diet or a low sodium diet in randomized order (HS-LS/ LS-HS). On the study day a hypertonic saline infusion was given.
Arm Title
Healthy Control Subjects, LS
Arm Type
Other
Arm Description
Each subject was studied on 2 separate days at least 3 weeks apart. During 4 days before the study day, the subjects consumed either a high sodium diet or a low sodium diet in randomized order (HS-LS/ LS-HS). On the study day a hypertonic saline infusion was given.
Intervention Type
Behavioral
Intervention Name(s)
High Sodium Diet
Intervention Description
250-350 mmol
Intervention Type
Behavioral
Intervention Name(s)
Low Sodium Diet
Intervention Description
25-35 mmol
Intervention Type
Behavioral
Intervention Name(s)
Hypertonic saline infusion
Intervention Description
7 ml/ kg of 3% saline were given over 30 minutes.
Primary Outcome Measure Information:
Title
u-AQP-2CR
Description
Urinary Aquaporin-2 corrected for creatinine
Time Frame
Before and after hypertonic saline infusion after 4 days on high and low sodium diet, respectively.
Secondary Outcome Measure Information:
Title
u-ENaC (beta)CR
Description
Urinary ENaC (beta) corrected for creatinine
Time Frame
Before and after hypertonic saline infusion after 4 days on high and low sodium diet, respectively.
Title
FENa
Description
fractional sodium excretion
Time Frame
Before and after hypertonic saline infusion after 4 days on high and low sodium diet, respectively.
Title
CH2O
Description
Free water excretion
Time Frame
Before and after hypertonic saline infusion after 4 days on high and low sodium diet, respectively.
Title
u-cAMP
Description
urinary excretion of cAMP
Time Frame
Before and after hypertonic saline infusion after 4 days on high and low sodium diet, respectively.
Title
uPGE-2
Description
urinary excretion of PGE-2
Time Frame
Before and after hypertonic saline infusion after 4 days on high and low sodium diet, respectively.
Title
GFR
Description
glomerular filtration rate
Time Frame
Before and after hypertonic saline infusion after 4 days on high and low sodium diet, respectively.
Title
p-vasopressin
Description
plasma concentration of vasopressin
Time Frame
Before and after hypertonic saline infusion after 4 days on high and low sodium diet, respectively.
Title
p-aldosterone.
Description
plasma concentration of aldosterone
Time Frame
Before and after hypertonic saline infusion after 4 days on high and low sodium diet, respectively.

10. Eligibility

Sex
All
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
65 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria: Caucasian men and women age 18-65 years BMI between 18,5-30,0 kg/m2 ADPKD, diagnosed by the following findings on ultra scan: for patients without ADPKD family history: > 5 bilateral cysts for patients with ADPKD family history: < 30 years: 2 cysts (unilateral or bilateral) 30-60 years: 2 or more bilateral cysts > 60 years: 4 or more bilateral cysts Kidney function: stadium 1-4. Exclusion Criteria: Other kidney disease Anamnestic or clinical signs of acute myocardial infarction, atrial fibrillation, heart valve disease or chronic heart failure Anamnestic or clinical signs of disease in lungs, liver,endocrine organs or brain or neoplastic disease Family history of rupture of intracerebral aneurisms Alcohol or drug abuse Smoking Medical treatment arat form antihypertensives and oral anticonceptives Pregnancy or breastfeeding
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Erling B. Pedersen, Professor
Organizational Affiliation
Department of Medical Research, Holstebro Hospital, Denmark
Official's Role
Study Chair
First Name & Middle Initial & Last Name & Degree
Carolina C. Graffe, MD
Organizational Affiliation
Department of Medical Research, Holstebro Hospital, Denmark
Official's Role
Principal Investigator
Facility Information:
Facility Name
Department of Medical Research, Holstebro Hospital
City
Holstebro
ZIP/Postal Code
7500
Country
Denmark

12. IPD Sharing Statement

Learn more about this trial

The Effect of High and Low Sodium Intake on Urinary Aquaporin-2 in Autosomal Dominant Polycystic Kidney Disease

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