Assessment of Endogenous Oxalate Synthesis

University of Alabama at Birmingham23 enrolled

Overview

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.

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 Type

INTERVENTIONAL

Allocation

Purpose

BASIC_SCIENCE

Masking

NONE

Enrollment

Conditions

Healthy Kidney Stone Obesity

Interventions

Low-oxalate controlled dietDIETARY_SUPPLEMENT

Participants will consume a diet that is controlled in its contents of protein, carbohydrates, fat, calcium, oxalate, vitamin C and sodium for 5 days. Participants will be asked not to take any dietary supplements, exercise strenuously, or consume food or drink that is not provided to them.

Primed, continuous intravenous infusion of 13C2-oxalateOTHER

Participants will receive a continuous intravenous administration of carbon-13 oxalate, a naturally occurring form of oxalate, over the course of several hours until steady-state is achieved, using an IV catheter, while remaining fasting.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 75 YearsHealthy volunteers:

Medical Language ↔ Plain English

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

Locations (1)

University of Alabama at Birmingham

Birmingham, Alabama, United States

Outcomes

Primary Outcomes

Endogenous Oxalate Synthesis Rate

Daily oxalate synthesis rate (mg/day) determined by the 13c2-oxalate infusion method

Time frame: day 5

Secondary Outcomes

Urinary Oxalate Excretion

24-hr urinary oxalate excretion (mg/day) after equilibration on the low-oxalate controlled diet, measured by ion chromatography coupled with mass spectrometry.

Time frame: day 3-4

Urinary Creatinine Excretion

24-hr urinary creatinine excretion (g/day) after equilibration on the low-oxalate controlled diet.

Time frame: day 3-4

Data from ClinicalTrials.gov

This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.