Renal Metabolism of Glycolate to Oxalate

May 27, 2026 updated by: Sonia Fargue, University of Alabama at Birmingham
This study will determine the contribution of glycolate metabolism to urinary oxalate excretion in healthy subjects, using carbon 13 isotope glycolate tracer technique and a low-oxalate controlled diet.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

It is known that glycolate, an intermediary molecule in normal metabolism, can be converted into oxalate. The origin of urinary oxalate is of interest as calcium oxalate is a main component of kidney stones. In the rare disease primary hyperoxaluria, excessive production of oxalate by the body results in frequent kidney stones and can cause loss of kidney function. Primary hyperoxaluria is caused by deficiencies in one of several enzymes involved in the glycolate pathway.

This study will seek to determine how much oxalate is formed from glycolate in normal subjects. After consuming a controlled diet, subjects will either ingest or have an intravenous infusion of carbon 13 glycolate, a stable isotope of glycolate that can be tracked and will also label downstream metabolic products. Blood and urine samples will be assessed for their amounts of labeled glycolate and labeled oxalate to provide an accurate measure of how much oxalate is made from normal glycolate breakdown in healthy human subjects.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
15

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • Alabama
      • Birmingham, Alabama, United States, 35233
        • University of Alabama at Birmingham

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

14 years to 71 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Mentally competent adults, able to read and comprehend the consent form
  • 18-75 years of age
  • Body Mass Index (BMI) between 19 and 40
  • In good health as judged from a medical history, reported medications, and a complete blood metabolic profile
  • Acceptable 24 hour urine collections (performed twice for screening)

Exclusion Criteria:

  • History of any hepatic, renal, bowel, or endocrine disease or any 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 <18 or >75
  • BMI <19 or >40

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Non-Randomized
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Constant Infusion of 13C2-Glycolate
Subjects will consume a controlled diet for 5 days total. On Days 3 and 4, subjects will collect 24 hour urines. On Day 5, they will come to the Clinical Research Unit (CRU) in the fasted state for a visit lasting from 7:00 am to 5:30 pm. An intravenous (IV) catheter will be placed in a vein on the back of the hand at 7:30 am for the carbon 13 glycolate infusion which will occur at a constant rate for 10 hours, following a priming dose. From 7:30 am to 5:30 pm, urine collections will occur hourly, and from 8:30 am to 5:30 pm, IV blood collections will occur every half hour. Subjects will receive a meal at 5:30 pm, thus concluding the CRU visit. At home, subjects will collect timed urine until the next morning to be returned to the CRU.
Dietary supplement: Low oxalate controlled Diet
Participants will consume a diet that is controlled in its contents of protein, carbohydrates, fat, calcium, oxalate, vitamin C and sodium. Participants will be asked not to take any dietary supplements, exercise strenuously, or consume food or drink that is not provided to them.
Other: Primed, continuous intravenous infusion of 13C2-Glycolate
Participants will receive a continuous intravenous administration of carbon-13 glycolate, a naturally occurring form of glycolate, over the course of several hours until steady-state is achieved, using an IV catheter.
Other Names:
  • Constant infusion of 13C2-Glycolate
Experimental: Single Intravenous Dose of 13C2-Glycolate
Subjects will consume a controlled diet for 5 days total. On Days 3 and 4, subjects will collect 24 hour urines. On Day 5, they will come to the Clinical Research Unit (CRU) in the fasted state for a visit lasting from 7:00 am to 2:30 pm. An intravenous (IV) catheter will be placed in a vein on the back of the hand at 8:30 am for a single dose of carbon-13 glycolate to be administered. From 7:30 am to 2:30 pm, urine collections will occur hourly. At 8:30 am, IV blood samples will be taken every fifteen minutes until 9:30 am, every half hour from 9:30 am to 10:30 am, and then finally hourly from 10:30 am to 2:30 pm . Subjects will receive a meal at 2:30 pm, thus concluding the CRU visit. At home, subjects will collect timed urine until the next morning to be returned to the CRU.
Dietary supplement: Low oxalate controlled Diet
Participants will consume a diet that is controlled in its contents of protein, carbohydrates, fat, calcium, oxalate, vitamin C and sodium. Participants will be asked not to take any dietary supplements, exercise strenuously, or consume food or drink that is not provided to them.
Other: Bolus intravenous infusion of 13C2-Glycolate
Participants will receive a bolus intravenous administration of carbon-13 glycolate, a naturally occurring form of glycolate, using an IV catheter.
Other Names:
  • Single intravenous dose of 13C2-Glycolate
Experimental: Single Oral Dose of 13C2-Glycolate
Subjects will consume a controlled diet for 5 days total. On Days 3 and 4, subjects will collect 24 hour urines. On Day 5, they will come to the Clinical Research Unit (CRU) in the fasted state for a visit lasting from 7:00 am to 2:30 pm. At 8:30 am, subjects will ingest the carbon-13 glycolate, dissolved in to 50 ml (about 1/4 cup) of water. From 7:30 am to 2:30 pm, urine collections will occur hourly. At 8:30 am, intravenous (IV) blood samples will be taken every fifteen minutes until 9:30 am, every half hour from 9:30 am to 10:30 am, and then finally hourly from 10:30 am to 2:30 pm . Subjects will receive a meal at 2:30 pm, thus concluding the CRU visit. At home, subjects will collect timed urine until the next morning to be returned to the CRU.
Dietary supplement: Low oxalate controlled Diet
Participants will consume a diet that is controlled in its contents of protein, carbohydrates, fat, calcium, oxalate, vitamin C and sodium. Participants will be asked not to take any dietary supplements, exercise strenuously, or consume food or drink that is not provided to them.
Other: Oral bolus administration of 13C2-Glycolate
Participants will orally ingest a single dose of carbon-13 glycolate, a naturally occurring form of glycolate.
Other Names:
  • Single oral dose of 13C2-Glycolate

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Urinary oxalate measured by ion chromatography coupled with mass spectrometry
Time Frame: day 5 of dietary control
Measurement of carbon 13 labeled and unlabeled urinary oxalate following carbon 13 glycolate administration, after equilibration under a low-oxalate diet.
day 5 of dietary control
Plasma glycolate measured by ion chromatography coupled with mass spectrometry
Time Frame: day 5 of dietary control
Measurement of carbon 13 labeled and unlabeled plasma glycolate following carbon 13 glycolate administration, after equilibration under a low-oxalate diet.
day 5 of dietary control

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Urinary creatinine
Time Frame: day 5 of dietary control
Baseline assessment of 24hr urinary creatinine under controlled low-oxalate diet.
day 5 of dietary control
Urinary glycolate measured by ion chromatography coupled with mass spectrometry
Time Frame: day 5 of dietary control
Measurement of carbon 13 labeled and unlabeled urinary glycolate following carbon 13 glycolate administration, after equilibration under a low-oxalate diet.
day 5 of dietary control

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Alabama at Birmingham

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Sonia Fargue, M.D., Ph.D., University of Alabama at Birmingham

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 12, 2020

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 15, 2020

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 16, 2020

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 18, 2020

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 29, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 27, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRB160505004-GLI
  • UAB (Other Identifier: UAB)
  • K01DK114332 (U.S. NIH Grant/Contract)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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