A Translational Approach to Gitelman Syndrome
Primary Purpose
Gitelman Syndrome
Status
Completed
Phase
Not Applicable
Locations
United States
Study Type
Interventional
Intervention
Hydrochlorothiazide
Sponsored by
About this trial
This is an interventional diagnostic trial for Gitelman Syndrome focused on measuring Hypokalemia, Bartter Syndrome, Salt Wasting
Eligibility Criteria
Inclusion Criteria:
- Institutional Review Board (IRB) approved written Informed Consent and Health Insurance Portability and Accountability Act (HIPAA) Authorization as per national regulations, must be obtained from the subject or legally authorized representative prior to any study-related procedures (including withdrawal of prohibited medication, if applicable).
- Subject is between the ages of 21 and 60.
- Female subjects of child bearing potential must have a negative urine pregnancy test at the screening visit (Study Visit 1) and must agree to maintain effective birth control during the study.
- Subjects who are referred to Dr. Ellison for evaluation of normotensive hypokalemia of unknown etiology
Exclusion Criteria:
- Subject has known allergy to thiazide or sulfonamide medications
- Subject is pregnant or lactating.
Subject has major systemic illnesses that affect potassium regulation through pathology or pharmacologic treatment. This category includes:
- Hypertension
- Requiring regular pharmacological control
- History of blood pressure greater than 140mmHg systolic and 90mmHg diastolic
- Congestive heart failure
- Cirrhosis of the liver
- Subject has documented kidney disease resulting in anuria, proteinuria or abnormal urinalysis, or requiring dialysis for treatment.
Sites / Locations
- Oregon Health & Science University
Arms of the Study
Arm 1
Arm Type
Experimental
Arm Label
Thiazide Response
Arm Description
Hydrochlorothiazide 50 mg will be administered by mouth once.
Outcomes
Primary Outcome Measures
Chloriuretic Response to a Thiaizde
Change from baseline in fractional chloride excretion in response to a single dose of hydrochlorothiazide
Secondary Outcome Measures
Full Information
NCT ID
NCT00822107
First Posted
January 13, 2009
Last Updated
April 1, 2019
Sponsor
Oregon Health and Science University
Collaborators
Oregon Clinical and Translational Research Institute
1. Study Identification
Unique Protocol Identification Number
NCT00822107
Brief Title
A Translational Approach to Gitelman Syndrome
Official Title
A Translational Approach to Gitelman Syndrome
Study Type
Interventional
2. Study Status
Record Verification Date
April 2019
Overall Recruitment Status
Completed
Study Start Date
January 2009 (undefined)
Primary Completion Date
January 2013 (Actual)
Study Completion Date
September 2013 (Actual)
3. Sponsor/Collaborators
Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
Oregon Health and Science University
Collaborators
Oregon Clinical and Translational Research Institute
4. Oversight
Data Monitoring Committee
No
5. Study Description
Brief Summary
This study will test the response to a single dose of thiazide diuretic as a diagnostic test for Gitelman syndrome. Individuals with hypokalemic alkalosis will be enrolled. After a baseline study, they will have the response to 50 mg hydrochlorothiazide on fractional chloride excretion examined.
Detailed Description
The purpose of this study is to test the hypothesis that Gitelman syndrome (GS) can be diagnosed using a simple clinical protocol. GS is an inherited kidney disease that usually shows up in patients as low blood potassium levels. Currently, no commercial genetic test for GS exists. Currently, GS is diagnosed based upon clinical findings but this method is not precise and often not reliable. Thus, in order to develop new treatments specific for GS patients, a more exact method of diagnosis would be of benefit.
Eligible subjects are men and women ages 21-60 with normal blood pressure who have been diagnosed with low blood potassium of uncertain cause. Subjects may withdraw at any time.
This study requires 3 visits to OHSU's campus. Study Visit 1 will occur during a normal visit with the nephrologist. As part of the normal visit, a complete interview, physical exam and urine and blood samples will be taken. In addition, another blood sample will be taken and used for genetic analysis. A urine pregnancy test will be administered. A Quality of Life survey, described below, will be administered. The genetic analysis, urine pregnancy test and Quality of Life survey are not normal tests for GS. Blood and urine samples, as well as pregnancy tests will be collected/administered at the Oregon Clinical and Translational Research Institute (OCTRI).
During the intervention period, subjects will refrain from taking their potassium sparing medications for 7 days. This period is called the washout period and is needed to ensure that blood tests during the hydrochlorthiazide (HCTZ, a "water pill") (see below), are not affected by medications. On the 3rd day of the washout period, Study Visit 2 will occur at the OCTRI. This will require blood to be drawn, to insure that subjects maintain proper blood levels of potassium and magnesium. Magnesium and potassium supplements will be allowed during the washout. After review of the blood test results, the investigator may adjust the doses of these supplements in order to keep subject blood levels of potassium and magnesium as close to normal as possible. Blood pressure, heart rate and breathing rate will also be checked at this visit.
Study Visit 3 will occur at the OCTRI and will be devoted to the HCTZ test. During the course of the HCTZ test, subjects will have an plastic tube (an IV) placed in an arm vein, have vital signs checked and receive 50mg of HCTZ to take by mouth . Subjects will provide 8 urine samples and 3 blood samples. The time required for this visit is expected to be 6 hours.
The total time required for subjects to complete the study from Study Visit 1 through discharge from the OCTRI on Study Visit 3 will not be less than 9 days and subjects should not expect the total length to exceed three weeks depending on available appointments for Study Visit 3 at the OCTRI.
The Quality of Life survey is derived from a national research corporation and has been modified for use in this study. The authors of this survey allow free public use of this document provided it is properly referenced in any presentation of the study's results.
HCTZ is an FDA approved medication. There are no experimental drugs or devices used in this study.
The purpose of this study is to develop methods for, and determine the feasibility of, performing a HCTZ test and genetic analysis for GS at OHSU. There is no statistical analysis of data, but descriptive characteristics will be entered into an Access database with password restricted access. Genetic samples will be analyzed using PCR and standard sequencing techniques. Data and samples will be stored for a maximum of 15 years.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Gitelman Syndrome
Keywords
Hypokalemia, Bartter Syndrome, Salt Wasting
7. Study Design
Primary Purpose
Diagnostic
Study Phase
Not Applicable
Interventional Study Model
Single Group Assignment
Masking
None (Open Label)
Allocation
N/A
Enrollment
8 (Actual)
8. Arms, Groups, and Interventions
Arm Title
Thiazide Response
Arm Type
Experimental
Arm Description
Hydrochlorothiazide 50 mg will be administered by mouth once.
Intervention Type
Drug
Intervention Name(s)
Hydrochlorothiazide
Other Intervention Name(s)
HCTZ
Intervention Description
50 mg one time
Primary Outcome Measure Information:
Title
Chloriuretic Response to a Thiaizde
Description
Change from baseline in fractional chloride excretion in response to a single dose of hydrochlorothiazide
Time Frame
6 hours
10. Eligibility
Sex
All
Minimum Age & Unit of Time
21 Years
Maximum Age & Unit of Time
65 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria:
Institutional Review Board (IRB) approved written Informed Consent and Health Insurance Portability and Accountability Act (HIPAA) Authorization as per national regulations, must be obtained from the subject or legally authorized representative prior to any study-related procedures (including withdrawal of prohibited medication, if applicable).
Subject is between the ages of 21 and 60.
Female subjects of child bearing potential must have a negative urine pregnancy test at the screening visit (Study Visit 1) and must agree to maintain effective birth control during the study.
Subjects who are referred to Dr. Ellison for evaluation of normotensive hypokalemia of unknown etiology
Exclusion Criteria:
Subject has known allergy to thiazide or sulfonamide medications
Subject is pregnant or lactating.
Subject has major systemic illnesses that affect potassium regulation through pathology or pharmacologic treatment. This category includes:
Hypertension
Requiring regular pharmacological control
History of blood pressure greater than 140mmHg systolic and 90mmHg diastolic
Congestive heart failure
Cirrhosis of the liver
Subject has documented kidney disease resulting in anuria, proteinuria or abnormal urinalysis, or requiring dialysis for treatment.
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
David H Ellison, MD
Organizational Affiliation
Oregon Health and Science University
Official's Role
Principal Investigator
Facility Information:
Facility Name
Oregon Health & Science University
City
Portland
State/Province
Oregon
ZIP/Postal Code
97239
Country
United States
12. IPD Sharing Statement
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A Translational Approach to Gitelman Syndrome
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