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Obesity and Uric Acid Stones Study

Primary Purpose

Obesity, Uric Acid Stones, Type 2 Diabetes Mellitus in Obese

Status
Recruiting
Phase
Phase 3
Locations
United States
Study Type
Interventional
Intervention
Phentermine / Topiramate Oral Product
Citrate Salts, Allopurinol, Diet
Sponsored by
University of Florida
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional treatment trial for Obesity

Eligibility Criteria

18 Years - 75 Years (Adult, Older Adult)All SexesDoes not accept healthy volunteers

Inclusion Criteria:

  • have recurrent pure uric acid nephrolithiasis (UAN) or mixed calcium oxalate (CO)/UAN. Recurrent stone disease is defined as at least two spontaneous kidney stone passages, two previous kidney stone procedures, or one previous stone passage and one previous procedure. Pure UAN is defined as at least one previous stone analysis demonstrating 100% uric acid mineral content. Mixed COUAN will be defined as at least one previous stone analysis with any mix of uric acid ≥80% and ≤20% calcium oxalate. If participant has more than one stone analysis, the most recent will be considered the current stone type.
  • have obesity, defined as BMI > 30 kg/m2.
  • have type 2 diabetes mellitus or pre-diabetes, defined as previously diagnosed by laboratory testing (hemoglobin A1c, fasting plasma glucose, or oral glucose tolerance test) or as demonstrated by use of anti-hyperglycemic medications or insulin.
  • have at least one 24-hour urine study off medications demonstrating urine pH < 5.8 or a study 24-hr urine demonstrating urine pH < 5.8

Exclusion Criteria:

  • contraindications to topiramate, including: recurrent major depression, current substantial depressive symptoms, uncontrolled depression by PHQ 9 score >= 10, history of suicidal ideation or behavior with intent to act (versus exclude those with depression); current pregnancy or attempting to conceive; pre-existing chronic kidney disease with eGFR < 60 at time of enrollment; active cancer or active treatment for cancer (chemotherapy, radiation); and non-ambulatory.
  • contraindications to phentermine, including: unstable cardiovascular disease defined as decompensated heart failure, unstable angina, atrial fibrillation, uncontrolled blood pressure (>160 systolic), hyperthyroidism; monoamine oxidase inhibitor use; current history of drug or alcohol abuse.

Sites / Locations

  • University of FloridaRecruiting

Arms of the Study

Arm 1

Arm 2

Arm Type

Experimental

Active Comparator

Arm Label

Allocated to intervention/treatment

Allocated to pragmatic control

Arm Description

Daily phentermine/topiramate x 18 months

Remain on their current regimen

Outcomes

Primary Outcome Measures

Kidney stone growth (mm2) as determined by non-contrast CT scan
Existing kidney stone growth
New kidney stone formation (mm2) as determined by non-contrast CT scan
Formation of a new kidney stone

Secondary Outcome Measures

Change in weight
Expressed as total percent body weight loss (total weight loss in pounds/starting weight in pounds)
Change in urinary pH parameters
Absolute change in urine pH (end of study compared to baseline)
Change in hemoglobin A1c
Percent change in A1c (end of study compared to baseline)
Change in urinary citrate parameters
Percent change in urinary citrate
Change in urinary calcium parameters
Percent change in urinary calcium
Change in urinary uric acid parameters
Percent change in urinary uric acid

Full Information

First Posted
November 3, 2020
Last Updated
June 9, 2023
Sponsor
University of Florida
Collaborators
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
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1. Study Identification

Unique Protocol Identification Number
NCT04621929
Brief Title
Obesity and Uric Acid Stones Study
Official Title
Phentermine/tOpiramate to eND Obesity and Uric Acid Stones Trial (POuND OUT)
Study Type
Interventional

2. Study Status

Record Verification Date
June 2023
Overall Recruitment Status
Recruiting
Study Start Date
March 31, 2021 (Actual)
Primary Completion Date
December 31, 2023 (Anticipated)
Study Completion Date
March 31, 2024 (Anticipated)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Sponsor
Name of the Sponsor
University of Florida
Collaborators
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

4. Oversight

Studies a U.S. FDA-regulated Drug Product
Yes
Studies a U.S. FDA-regulated Device Product
No
Product Manufactured in and Exported from the U.S.
Yes
Data Monitoring Committee
Yes

5. Study Description

Brief Summary
The investigator proposes an 18 month, feasibility pilot study, randomizing obese and diabetic individuals with pure uric acid nephrolithiasis (UAN) or mixed calcium oxalate (CO) UAN to either phentermine/topiramate or a pragmatic control group who will remain on their standard medication regimen (citrate salts, allopurinol, diet, etc.).
Detailed Description
Mounting evidence indicates that obesity, diabetes mellitus, and kidney stones are inter-connected diseases, particularly uric acid nephrolithiasis (UAN) with or without components of calcium oxalate (CO). Obese or overweight diabetics have a six-fold increased risk to develop UAN/COUAN due to the inability to properly add buffer (ammonium) to urine. Of the FDA approved drugs in the weight loss market, the combination medication phentermine/ topiramate is the most effective and has a unique side effect of alkalinizing the urine (making it less acidic). The hypothesize of this project is that treatment of obese, diabetic patients with phentermine/topiramate will reduce the incidence of UAN/COUAN by 1) direct urinary alkalinization and 2) weight loss. Weight loss will indirectly improve urinary buffering ability through improvement in insulin sensitivity and will decrease renal oxidative stress. The investigative team proposes an 18 month, feasibility pilot study, randomizing 30 obese and diabetic individuals with UAN/COUAN to either phentermine/topiramate (n=20) or a pragmatic control group (n=10) who would remain on standard medication regimen (citrate salts, allopurinol, diet, etc).

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Obesity, Uric Acid Stones, Type 2 Diabetes Mellitus in Obese, Pre-Diabetes

7. Study Design

Primary Purpose
Treatment
Study Phase
Phase 3
Interventional Study Model
Parallel Assignment
Model Description
2:1 ratio block site of 6
Masking
None (Open Label)
Allocation
Randomized
Enrollment
40 (Anticipated)

8. Arms, Groups, and Interventions

Arm Title
Allocated to intervention/treatment
Arm Type
Experimental
Arm Description
Daily phentermine/topiramate x 18 months
Arm Title
Allocated to pragmatic control
Arm Type
Active Comparator
Arm Description
Remain on their current regimen
Intervention Type
Drug
Intervention Name(s)
Phentermine / Topiramate Oral Product
Intervention Description
All participants in the experimental group will receive oral generic tablet phentermine (18.75 or 37.5 mg dose) and topiramate (daily 100 mg or 150 mg dose)
Intervention Type
Combination Product
Intervention Name(s)
Citrate Salts, Allopurinol, Diet
Intervention Description
Control participants will complete initial visit requirements and study enrollment and will be maintained on their current therapy.
Primary Outcome Measure Information:
Title
Kidney stone growth (mm2) as determined by non-contrast CT scan
Description
Existing kidney stone growth
Time Frame
18 months
Title
New kidney stone formation (mm2) as determined by non-contrast CT scan
Description
Formation of a new kidney stone
Time Frame
18 months
Secondary Outcome Measure Information:
Title
Change in weight
Description
Expressed as total percent body weight loss (total weight loss in pounds/starting weight in pounds)
Time Frame
18 months
Title
Change in urinary pH parameters
Description
Absolute change in urine pH (end of study compared to baseline)
Time Frame
18 months
Title
Change in hemoglobin A1c
Description
Percent change in A1c (end of study compared to baseline)
Time Frame
18 months
Title
Change in urinary citrate parameters
Description
Percent change in urinary citrate
Time Frame
18 months
Title
Change in urinary calcium parameters
Description
Percent change in urinary calcium
Time Frame
18 months
Title
Change in urinary uric acid parameters
Description
Percent change in urinary uric acid
Time Frame
18 months

10. Eligibility

Sex
All
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
75 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria: have recurrent pure uric acid nephrolithiasis (UAN) or mixed calcium oxalate (CO)/UAN. Recurrent stone disease is defined as at least two spontaneous kidney stone passages, two previous kidney stone procedures, or one previous stone passage and one previous procedure. Pure UAN is defined as at least one previous stone analysis demonstrating 100% uric acid mineral content. Mixed COUAN will be defined as at least one previous stone analysis with any mix of uric acid ≥80% and ≤20% calcium oxalate. If participant has more than one stone analysis, the most recent will be considered the current stone type. have obesity, defined as BMI > 30 kg/m2. have type 2 diabetes mellitus or pre-diabetes, defined as previously diagnosed by laboratory testing (hemoglobin A1c, fasting plasma glucose, or oral glucose tolerance test) or as demonstrated by use of anti-hyperglycemic medications or insulin. have at least one 24-hour urine study off medications demonstrating urine pH < 5.8 or a study 24-hr urine demonstrating urine pH < 5.8 Exclusion Criteria: contraindications to topiramate, including: recurrent major depression, current substantial depressive symptoms, uncontrolled depression by PHQ 9 score >= 10, history of suicidal ideation or behavior with intent to act (versus exclude those with depression); current pregnancy or attempting to conceive; pre-existing chronic kidney disease with eGFR < 60 at time of enrollment; active cancer or active treatment for cancer (chemotherapy, radiation); and non-ambulatory. contraindications to phentermine, including: unstable cardiovascular disease defined as decompensated heart failure, unstable angina, atrial fibrillation, uncontrolled blood pressure (>160 systolic), hyperthyroidism; monoamine oxidase inhibitor use; current history of drug or alcohol abuse.
Central Contact Person:
First Name & Middle Initial & Last Name or Official Title & Degree
John Marks
Phone
352-273-5618
Email
marksjg@ufl.edu
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Benjamin Canales, MD
Organizational Affiliation
University of Florida
Official's Role
Principal Investigator
Facility Information:
Facility Name
University of Florida
City
Gainesville
State/Province
Florida
ZIP/Postal Code
32610
Country
United States
Individual Site Status
Recruiting
Facility Contact:
First Name & Middle Initial & Last Name & Degree
John Marks
Phone
352-273-5618
Email
marksjg@ufl.edu
First Name & Middle Initial & Last Name & Degree
Benjamin Canales

12. IPD Sharing Statement

Plan to Share IPD
No

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Obesity and Uric Acid Stones Study

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