Influence of Obesity on Oxalate Metabolism and Handling in Calcium Oxalate Stone Formers

Kidney Stone Clinical Trial

Official title:

Influence of Obesity on Oxalate Metabolism and Handling in Calcium Oxalate Stone Formers

Clinical Trial Details — Status: Active, not recruiting

Administrative data

• NCT number: NCT04333745
• Other study ID #: IRB-300004693
• Status: Active, not recruiting
• Phase: N/A
• Start date: September 1, 2021
• Est. completion date: December 1, 2025

Study information

• Verified date: February 2024
• Source: University of Alabama at Birmingham
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The primary goals of this study are to determine the contribution of dietary oxalate absorption, renal oxalate handling, and endogenous oxalate synthesis to urinary oxalate excretion in normal Body Mass Index (BMI) and obese calcium oxalate kidney stone formers.

Recruitment information / eligibility

• Status: Active, not recruiting
• Enrollment: 22
• Est. completion date: December 1, 2025
• Est. primary completion date: December 1, 2024
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 19 Years to 75 Years

Eligibility

Inclusion Criteria:

• Normal Body Mass Index (= 18.5 to < 25); Obese Body Mass Index (= 30 to = 45)

• Able to provide informed consent

• Willingness to consume controlled diet

• Composition of most recent stone > 50% calcium oxalate, no uric acid component

• First time or recurrent calcium oxalate stone former

• 24-hour urine collections with creatinine values within 20% of appropriate ratio of creatinine (mg)/body weight (kg) for gender, and with creatinine values that are consistent between collections (within 20% of each other)

• Willingness to stop supplements [vitamins, Ca (citrate or carbonate) and other minerals, herbal supplements, nutritional aids, probiotics] for 14 days before start and during study

• Willingness to not undertake vigorous exercise during the controlled dietary study

• Normal fasting blood Comprehensive Metabolic Panel

• Hemoglobin A1c < 6.5%

• No food allergies or intolerance to any of the food in study menus

• Permitted/willing to discontinue medications for kidney stone prevention, including thiazides, allopurinol, and febuxostat and citrate preparations, for 14 days before start and during the studies. They will be instructed to restart these medications at the conclusion of the study

Exclusion Criteria:

• Diabetes

• Abnormal fasting comprehensive metabolic panel (CMP)

• Hemoglobin A1c (HbA1c) result = 6.5%

• Gout

• Estimated Glomerular Filtration Rate (eGFR) <60 ml/min/1.73m^2

• Primary hyperoxaluria

• Cystic fibrosis

• Cystinuria

• Uric acid stone former

• Utilization of immunosuppressive medication

• Nephrotic syndrome

• Enteric hyperoxaluria

• Gastrointestinal disorder that could impact oxalate transport

• Sarcoidosis

• Uncontrolled hypertension

• Renal tubular acidosis

• Primary hyperparathyroidism

• Liver disease

• Neurogenic bladder

• Urinary diversion

• Chronic diarrhea

• Bariatric surgery

• Active malignancy or treatment for malignancy within 12 months prior to screening

• Pregnancy

• Breast feeding/nursing

• Females of child bearing age who are not able to use an effective method of birth control during the study

• Mental/medical condition that is likely to impede successful study completion

• Illness including flu / common cold / fever 14 days before study and during study

• Diarrhea or other abnormal gastrointestinal event (e.g. abnormal bowel movements) 14 days before study or during study

• Antibiotic use within last 6 months (based on recommendations of the NIH Human Microbiome Project, Protocol A)

• Inability or unwillingness to undergo MRI

Related Conditions & MeSH terms

• Kidney Calculi
• Kidney Stone
• Nephrolithiasis

Intervention

Other:
• Controlled Diet
Participant will consume a controlled low oxalate diet for five days

Dietary Supplement:
• Carbon-13 Oxalate and Sucralose Ingestion
Subjects will ingest a small amount of carbon-13 oxalate and sucralose, dissolved in water.

Locations

Country	Name	City	State
United States	University of Alabama at Birmingham	Birmingham	Alabama
United States	University of Texas Southwestern Medical Center	Dallas	Texas

Sponsors (1)

Lead Sponsor	Collaborator
University of Alabama at Birmingham

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Urinary Oxalate Excretion	Urinary oxalate excretion from urine samples will be measured as mg/day	Baseline through Day 5