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Effect of Weight Loss on Urinary Oxalate Excretion in Obese Calcium Oxalate Kidney Stone Formers

Primary Purpose

Kidney Stone

Status
Recruiting
Phase
Not Applicable
Locations
United States
Study Type
Interventional
Intervention
Low Oxalate Diet before Weight Loss
Oral load of oxalate and sucralose before Weight Loss
Optifast VLCD Program
Optifast VLCD Transition Phase
Low Oxalate Diet after Weight Loss
Oral load of oxalate and sucralose after Weight Loss
Sponsored by
University of Alabama at Birmingham
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional basic science trial for Kidney Stone

Eligibility Criteria

19 Years - 65 Years (Adult, Older Adult)All SexesDoes not accept healthy volunteers

Inclusion Criteria:

  • First time or recurrent calcium oxalate stone formers defined as composition of most recent stone >50% calcium oxalate without uric acid component
  • Last stone passage or removal greater than 3 months prior to screening
  • Body Mass Index (BMI) between 30 and 45 kg/m2
  • Able to provide consent
  • Hemoglobin A1C <6.5%
  • Normal fasting blood CMP: Normal serum Na, K, Cl, CO2, Calcium, Albumin, AST, ALT <2 times upper limit of normal, Glucose <126 mg/dl, eGFR >60 ml/min/1.73 m2.
  • 24-hour urine collection with creatinine within 20% of gender appropriate (mg creat/kg body weight) and consistent between collections (within 20% of each other)
  • Willing to ingest menus prepared at the University of Alabama and University of Texas Southwestern Clinical Research Units
  • Willing to consume the Optifast VLCD diet
  • Willing to ingest menus prepared in Metabolic kitchen. No food allergies or intolerance to any of the foods in study menus. Substitutions for lactose intolerance will be made.
  • Willing to avoid vigorous exercise during eucaloric, low-oxalate dietary phase
  • Willing to stop use of weight-loss medications
  • Willing to stop for 14 days before and during study: medications for stone prevention including diuretics, potassium citrate, allopurinol, febuxostat, and calcium, nutritional, or herbal supplements
  • Those with controlled hypertension (systolic blood pressure <160 mmHg, diastolic <90 mmHg) will be included.
  • Those without severe dyslipidemia (LDL <200 mg/dL, HDL >30 mg/dL, and triglycerides <250 mg/dL) will be included. Treated and controlled dyslipidemia is accepted
  • Smoking/chewing tobacco/vaping will be allowed

Exclusion Criteria:

  • Renal colic or past stone surgery in the past 3 months
  • Estimated Glomerular Filtration Rate (eGFR) less than 60 ml/min/1.73m2
  • History of type 2 diabetes or screening hgb A1c greater than or equal to 6.5%
  • Alcohol or drug abuse. Alcohol consumption >12 units per week and/or unwillingness to abstain from alcohol consumption 2 days before and during the study.
  • Mental/medical condition likely to impede study completion
  • Current/planned pregnancy or breastfeeding in coming 6 months, unwillingness to use effective method of birth control during the study for individuals of childbearing potential.
  • Planned vacation in coming 4 months
  • Febrile illness including flu/common cold/COVID-19 within 21 days of study start
  • Primary or enteric hyperoxaluria
  • Gastrointestinal disorder or surgery that impacts oxalate transport
  • Cirrhosis, pancreatic or biliary disorder, porphyria, gout
  • Malignancy treated within the past 12 months
  • Nephrotic syndrome, neurogenic bladder, urinary diversion
  • History of primary hyperparathyroidism, cystinuria, renal tubular acidosis, sarcoidosis, cystic fibrosis
  • Uncontrolled hypertension, myocardial infarction in past 6 months, unstable angina, congestive heart failure
  • Antibiotic use in last 6 months
  • Medications: Topiramate, acetazolamide, zonisamide, diuretics, SGLT2-inhibitors, immunosuppressants

Sites / Locations

  • University of Alabama at BirminghamRecruiting

Arms of the Study

Arm 1

Arm Type

Experimental

Arm Label

Controlled Diet and Weight Loss Program

Arm Description

Subjects will consume a low oxalate diet with blood and urine collections to establish baseline levels before undergoing a weight loss program with Optifast VLCD products. After completing the weight loss program, subjects will once again consume a low oxalate diet with blood and urine collections to observe any changes that may have occurred due to the weight loss.

Outcomes

Primary Outcome Measures

Measurement of 24 hour urinary oxalate excretion
Subjects will ingest a controlled diet low in oxalate and collect 2 x 24-hour urines before and after the Optifast VLCD Program. The utilization of a low oxalate diet allows assessment of the change in contribution of endogenous oxalate synthesis to the urinary oxalate pool.

Secondary Outcome Measures

Full Information

First Posted
November 11, 2020
Last Updated
January 23, 2023
Sponsor
University of Alabama at Birmingham
Collaborators
University of Texas Southwestern Medical Center
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1. Study Identification

Unique Protocol Identification Number
NCT04633811
Brief Title
Effect of Weight Loss on Urinary Oxalate Excretion in Obese Calcium Oxalate Kidney Stone Formers
Official Title
Effect of Weight Loss on Urinary Oxalate Excretion in Obese Calcium Oxalate Kidney Stone
Study Type
Interventional

2. Study Status

Record Verification Date
January 2023
Overall Recruitment Status
Recruiting
Study Start Date
December 3, 2021 (Actual)
Primary Completion Date
January 1, 2024 (Anticipated)
Study Completion Date
March 31, 2024 (Anticipated)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
University of Alabama at Birmingham
Collaborators
University of Texas Southwestern Medical Center

4. Oversight

Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Data Monitoring Committee
Yes

5. Study Description

Brief Summary
This protocol seeks to determine if weight reduction with the Optifast VLCD program leads to reduced contribution of endogenous oxalate synthesis to the urinary oxalate pool in obese calcium oxalate stone formers.
Detailed Description
Obese adults (≥19 and ≤ 65 years) with a history of calcium oxalate kidney stone disease will be recruited at both University of Alabama at Birmingham (UAB) and University of Texas South Western (UTSW). Following consent, subjects will complete a screening phase, which includes (1) a meeting with a dietitian to ensure willingness to consume controlled ultra-low oxalate diets and determine anthropometric measurements and blood pressure, (2) collection of fasted blood and 2 x 24-hour urine specimens on self-choice diets to determine general health status and urinary chemistries, respectively, (3) completion of a 7-day run-in diet that includes the use of one serving of an Optifast meal daily to assess tolerance to Optifast VLCD® products. Participants will then consume an eucaloric, ultra-low oxalate controlled diet for 6 days. The controlled dietary phase involves 2 days of dietary equilibration, followed by 2 x 24-hour urine collections, and on the 5th day a dietary oxalate/sucralose oral load. Following the dietary oxalate/sucralose oral load, subjects will have blood collected every 30 minutes and collect 1-hour urines. Participants will then go on an intensive 14-week Optifast VLCD® Program to induce weight loss. At the end of this Optifast VLCD® Program participants will again perform the low oxalate controlled diet and dietary/sucralose oral load study. A total of 40 adult obese calcium oxalate kidney stone formers (20 male and 20 female) will be enrolled (20 at UAB and 20 at UTSW).

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Kidney Stone

7. Study Design

Primary Purpose
Basic Science
Study Phase
Not Applicable
Interventional Study Model
Single Group Assignment
Masking
None (Open Label)
Allocation
N/A
Enrollment
40 (Anticipated)

8. Arms, Groups, and Interventions

Arm Title
Controlled Diet and Weight Loss Program
Arm Type
Experimental
Arm Description
Subjects will consume a low oxalate diet with blood and urine collections to establish baseline levels before undergoing a weight loss program with Optifast VLCD products. After completing the weight loss program, subjects will once again consume a low oxalate diet with blood and urine collections to observe any changes that may have occurred due to the weight loss.
Intervention Type
Dietary Supplement
Intervention Name(s)
Low Oxalate Diet before Weight Loss
Intervention Description
Subjects will be instructed to ingest a controlled diet low in oxalate for a total of 6 days. 2 x 24 hour urines will be collected on days 3 and 4.
Intervention Type
Dietary Supplement
Intervention Name(s)
Oral load of oxalate and sucralose before Weight Loss
Intervention Description
Subjects will ingest 100mg carbon-13 oxalate, and 2 grams of sucralose on day 5 of the 6-day low oxalate diet phase. Following the oral load, blood and urine will be collected every 30 minutes and hourly, respectively
Intervention Type
Dietary Supplement
Intervention Name(s)
Optifast VLCD Program
Intervention Description
Subjects will go on a 10-week Intestive level Optifast VLCD weight loss program
Intervention Type
Dietary Supplement
Intervention Name(s)
Optifast VLCD Transition Phase
Intervention Description
After completion of the 10-week Optifast VLCD Program, subjects will be weaned off the Optifast products for 4 weeks.
Intervention Type
Dietary Supplement
Intervention Name(s)
Low Oxalate Diet after Weight Loss
Intervention Description
Subjects will be instructed to ingest a controlled diet low in oxalate for a total of 11 days and collect 2 x 24 hour urines on days 8 and 9
Intervention Type
Dietary Supplement
Intervention Name(s)
Oral load of oxalate and sucralose after Weight Loss
Intervention Description
Subjects will ingest 100mg carbon-13 oxalate, and 2 grams of sucralose on day 10 of the 11-day low oxalate diet phase. Following the oral load, blood and urine will be collected every 30 minutes and hourly, respectively
Primary Outcome Measure Information:
Title
Measurement of 24 hour urinary oxalate excretion
Description
Subjects will ingest a controlled diet low in oxalate and collect 2 x 24-hour urines before and after the Optifast VLCD Program. The utilization of a low oxalate diet allows assessment of the change in contribution of endogenous oxalate synthesis to the urinary oxalate pool.
Time Frame
4 days

10. Eligibility

Sex
All
Minimum Age & Unit of Time
19 Years
Maximum Age & Unit of Time
65 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria: First time or recurrent calcium oxalate stone formers defined as composition of most recent stone >50% calcium oxalate without uric acid component Last stone passage or removal greater than 3 months prior to screening Body Mass Index (BMI) >35 kg/m2 Able to provide consent Hemoglobin A1C <6.5% Normal fasting blood CMP: Normal serum Na, K, Cl, CO2, Calcium, Albumin, AST, ALT <2 times upper limit of normal, Glucose <126 mg/dl, eGFR >60 ml/min/1.73 m2. 24-hour urine collection with creatinine within 20% of gender appropriate (mg creat/kg body weight) and consistent between collections (within 20% of each other) Willing to ingest menus prepared at the University of Alabama and University of Texas Southwestern Clinical Research Units Willing to consume the Optifast VLCD diet Willing to ingest menus prepared in Metabolic kitchen. No food allergies or intolerance to any of the foods in study menus. Substitutions for lactose intolerance will be made. Willing to avoid vigorous exercise during eucaloric, low-oxalate dietary phase Willing to stop use of weight-loss medications Willing to stop for 14 days before and during study: medications for stone prevention including diuretics, potassium citrate, allopurinol, febuxostat, and calcium, nutritional, or herbal supplements Those with controlled hypertension (systolic blood pressure <160 mmHg, diastolic <90 mmHg) will be included. Those without severe dyslipidemia (LDL <200 mg/dL, HDL >30 mg/dL, and triglycerides <250 mg/dL) will be included. Treated and controlled dyslipidemia is accepted Smoking/chewing tobacco/vaping will be allowed Exclusion Criteria: Renal colic or past stone surgery in the past 3 months Estimated Glomerular Filtration Rate (eGFR) less than 60 ml/min/1.73m2 History of type 2 diabetes or screening hgb A1c greater than or equal to 6.5% Alcohol or drug abuse. Alcohol consumption >12 units per week and/or unwillingness to abstain from alcohol consumption 2 days before and during the study. Mental/medical condition likely to impede study completion Current/planned pregnancy or breastfeeding in coming 6 months, unwillingness to use effective method of birth control during the study for individuals of childbearing potential. Planned vacation in coming 4 months Febrile illness including flu/common cold/COVID-19 within 21 days of study start Primary or enteric hyperoxaluria Gastrointestinal disorder or surgery that impacts oxalate transport Cirrhosis, pancreatic or biliary disorder, porphyria, gout Malignancy treated within the past 12 months Nephrotic syndrome, neurogenic bladder, urinary diversion History of primary hyperparathyroidism, cystinuria, renal tubular acidosis, sarcoidosis, cystic fibrosis Uncontrolled hypertension, myocardial infarction in past 6 months, unstable angina, congestive heart failure Medications: Topiramate, acetazolamide, zonisamide, diuretics, SGLT2-inhibitors, immunosuppressants
Central Contact Person:
First Name & Middle Initial & Last Name or Official Title & Degree
Jane Vines, MPH
Phone
205-224-7324
Email
kidneystoneresearch@uabmc.edu
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Dean Assimos, MD
Organizational Affiliation
University of Alabama at Birmingham
Official's Role
Principal Investigator
Facility Information:
Facility Name
University of Alabama at Birmingham
City
Birmingham
State/Province
Alabama
ZIP/Postal Code
35243
Country
United States
Individual Site Status
Recruiting
Facility Contact:
First Name & Middle Initial & Last Name & Degree
Jane Vines, MPH
Phone
205-224-7324
Email
kidneystoneresearch@uabmc.edu

12. IPD Sharing Statement

Plan to Share IPD
No

Learn more about this trial

Effect of Weight Loss on Urinary Oxalate Excretion in Obese Calcium Oxalate Kidney Stone Formers

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