Assessment of Endogenous Oxalate Synthesis

Not Applicable

Completed

• Conditions: Kidney Stone; Obesity; Healthy

• Registration Number: NCT05229952
• Lead Sponsor: University of Alabama at Birmingham

Brief Summary

This study aims to determine the daily rate of endogenous synthesis of oxalate using carbon 13 oxalate isotope tracer technique and a low-oxalate controlled diet.

Detailed Description

Urinary oxalate excretion is derived from both dietary sources and endogenous synthesis. This study will use low-oxalate controlled diet and intravenous infusion of the isotope tracer carbon 13 oxalate, timed with blood and urine collections, to determine the daily rate of endogenous oxalate synthesis in non-stone forming volunteers and in subjects with calcium oxalate kidney stones. A DXA scan will be used to assess body composition.

Study Timeline

• Study First Submitted: 2022-01-27
• Study First Submitted QC: 2022-01-27
• Study First Posted: 2022-02-08
• Study Start: 2022-02-10
• Primary Completion: 2024-09-09
• Study Completion: 2024-09-09
• Results First Submitted: 2024-09-10
• Results First Submitted QC: 2024-12-08
• Results First Posted: 2024-12-11
• Status Verified: 2025-05
• Last Update Submitted: 2025-05-09
• Last Update Posted: 2025-05-13

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 23

Inclusion Criteria

• Mentally competent adults, able to read and comprehend the consent form
• Body Mass Index (BMI) between 18.5 and 50 kg/m2
• Acceptable 24 hour urine collections (judged on screening)
• good health as judged from a medical history, reported medications, and a complete blood metabolic profile
• with or without history of calcium oxalate kidney stones

Exclusion Criteria

• History of any hepatic, bowel, or endocrine disease or other condition that may influence the absorption, transport or urine excretion of ions
• Abnormal urine chemistries or blood metabolic profiles
• Poor 24 hour urine collections completed during screening, judged by 24 hour urine creatinine excretion (indicative of not collecting all urine in the 24 hour period)
• Pregnancy, intention to become pregnant in the near future, or lactation
• Aged lower than 18 or greater than 75 years
• BMI lower than18.5 or greater than 50 kg/m2

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SEQUENTIAL

Primary Outcome Measures

Name	Time	Method
Endogenous Oxalate Synthesis Rate	day 5	Daily oxalate synthesis rate (mg/day) determined by the 13c2-oxalate infusion method

Secondary Outcome Measures

Name	Time	Method
Urinary Creatinine Excretion	day 3-4	24-hr urinary creatinine excretion (g/day) after equilibration on the low-oxalate controlled diet.
Urinary Oxalate Excretion	day 3-4	24-hr urinary oxalate excretion (mg/day) after equilibration on the low-oxalate controlled diet, measured by ion chromatography coupled with mass spectrometry.

Trial Locations

Locations (1)

University of Alabama at Birmingham; 🇺🇸 Birmingham, Alabama, United States