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Completed

NCT Number: NCT05229952

Assessment of Endogenous Oxalate Synthesis

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.

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Key information

Conditions

Healthy Body Weight Calculi Female Urogenital Diseases Female Urogenital Diseases and Pregnancy Complications Kidney Calculi Kidney Diseases Kidney Stone Male Urogenital Diseases Nephrolithiasis Nutrition Disorders Nutritional and Metabolic Diseases Obesity Overnutrition Overweight Pathological Conditions, Anatomical Pathological Conditions, Signs and Symptoms Signs and Symptoms Urinary Calculi Urogenital Diseases Urolithiasis Urologic Diseases

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Alabama at Birmingham

Birmingham, Alabama, 35294, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Low-oxalate controlled diet

Dietary 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-oxalate

Other

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.

Primary outcomes

  1. Endogenous Oxalate Synthesis Rate

    Time frame: day 5

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

Secondary outcomes

  1. Urinary Oxalate Excretion

    Time frame: 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.

  2. Urinary Creatinine Excretion

    Time frame: day 3-4

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

Sponsors and collaborators

Lead sponsor

University of Alabama at Birmingham

Other

Registry information

Important dates

Study start
2022
Primary completion
2024
Study completion
2024
First posted
Feb 8, 2022
Registry last updated
May 13, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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