ObesityNCT03808090
Obesity and Endogenous Oxalate Synthesis
A study testing Normal Individuals in people with Obesity, run by University of Alabama at Birmingham at 1 site in United States.
Trial summary
The goal of this study is to determine if obesity is associated with increased endogenous oxalate synthesis as assessed by urinary oxalate excretion, which is a known risk factor for calcium oxalate kidney stones. The study will recruit adult participants without history of kidney stones. Read more about this study
- Who is it for?
- Ages 19 to 70 yearsHealthy volunteers can take part
- Conditions the study is for
- Obesity
- What is being tested?
- Normal Individuals
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 58 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jan 2013to 31 Jul 2024
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 19 to 70 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Age 19-70 yrs Body Mass Index > 18.5 kg/m2 Normal fasting serum electrolytes on comprehensive metabolic profile Willing to ingest fixed diets
Who cannot join
- Chronic Kidney Disease, estimated glomerular filtration rate < 60 ml/mn/1.73m2 Primary hyperoxaluria Liver, endocrine or renal diseases or any other condition that may influence the absorption, transport or urinary excretion of ions, which will compromise the interpretation of results, including: Cystic fibrosis, Cystinuria, Uric acid stone former, Nephrotic syndrome, Sarcoidosis, Renal tubular acidosis, Primary hyperparathyroidism, Neurogenic bladder, Urinary diversion Pregnancy or breast-feeding Incompatible dietary requirements with the study, food allergies or intolerance to any of the foods in study menus Active malignancy or treatment for malignancy within 12 months prior to screening Utilization of immunosuppressive medication Uncontrolled Hypertension or diabetes
Trial locations and contacts
1 site in 1 country.
United States1 site
University of Alabama at Birmingham
Birmingham, Alabama, 35294
About this study
The goal of this study is to determine if obesity is associated with increased endogenous oxalate synthesis as assessed by urinary oxalate excretion, which is a known risk factor for calcium oxalate kidney stones.
The study will recruit adult participants without history of kidney stones. Participants will
- Ingest fixed diets containing low amounts of oxalate for 4 days
- Collect 24-hr urine samples during the fixed diet
Read the detailed description
In this study the investigators propose to measure the excretion of urinary oxalate on a fixed diet with controlled amounts of oxalate, in individuals of varying body sizes without history of kidney stones. The 24-hr urinary oxalate excretion on such a low-oxalate normal calcium fixed diet is determined to be an appropriate surrogate for endogenous oxalate synthesis.
Screening phase. The study will enroll 60 individuals without history of kidney stones (30 males/30 females) at the University of Alabama at Birmingham (UAB).
Screening will include blood complete metabolic profile, 24-hr urine specimens collected at home on self-selected diets and anthropometric measurements.
Dietary phase Participants will ingest a low-oxalate (<60 mg/day), normal calcium (1000 mg/day) fixed diet for 4 consecutive days, collect three 24-hr urines after 1 day of dietary equilibration and have a fasted blood draw on day 5.
- Conditions
- Obesity
- Being tested
- Normal Individuals
- Keywords
- oxalate, obesity, kidney stones
- Medical subject headings
- Obesity, Kidney Calculi
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Normal IndividualsDietary supplement
Controlled Dietary phase: Low oxalate fixed diet
4 days of fixed normal calorie diet with low oxalate (< 60 mg/day), normal calcium (800-1200 mg/day)
| Study group | Role | What they receive |
|---|---|---|
| Normal Individuals | Experimental | Normal individuals: no prior history of kidney stones Receives: Dietary Supplement: Normal Individuals |
What is being measured
The primary outcome is the main question the study is designed to answer.
Urinary Oxalate Excretion
Mean Urinary oxalate excretion from three 24 hour urine collections on the fixed diet (mg/day)
Measured: 3 days on the fixed diet
Secondary outcomes (2)
Urinary Glycolate Excretion
mean of three 24-hr urinary glycolate collected on the fixed diet (mg/day)
Measured: 3 days on fixed diet
Urinary Creatinine Excretion
mean of there 24hr urinary creatinine excretion on the fixed diet ( g/day)
Measured: 3 days on the fixed diet
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Jan 2019
- Study start1 Jan 2013
- Primary completion1 Jul 2023
- Study completion31 Jul 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for ObesityStudies of the same condition, open and under way.
- More trials run by University of Alabama at BirminghamThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 58 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Alabama at Birmingham
- Sponsor type
- University, hospital or other
- Collaborators
- National Institutes of Health (NIH), National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Responsible party
- Principal investigator, Kyle D. Wood, University of Alabama at Birmingham
- Investigators
- Kyle D Wood, MD, Principal investigator, University of Alabama at Birmingham
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03808090
- Sponsor's protocol ID
- IRB130502007-OBE
- Other IDs
- 1K08DK115833-01A1
- Status last verified
- May 2026
- First submitted
- 26 Dec 2018
- Last updated
- 21 Sep 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 21 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Obesity and Endogenous Oxalate Synthesis
- ClinicalTrials.gov ID
- NCT03808090
- Acronym / sponsor ID
- IRB130502007-OBE
- Conditions
- Obesity
- Keywords
- oxalate, obesity, kidney stones
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 58 participants (actual)
- Lead sponsor
- University of Alabama at BirminghamUniversity, hospital or other
- Collaborators
- National Institutes of Health (NIH), National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Study start
- 1 Jan 2013 (actual)
- Primary completion
- 1 Jul 2023 (actual)
- Study completion
- 31 Jul 2024 (actual)
- First posted
- 17 Jan 2019 (actual)
- Results
- Posted 12 Aug 2024
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this study is to determine if obesity is associated with increased endogenous oxalate synthesis as assessed by urinary oxalate excretion, which is a known risk factor for calcium oxalate kidney stones.
The study will recruit adult participants without history of kidney stones. Participants will
- Ingest fixed diets containing low amounts of oxalate for 4 days
- Collect 24-hr urine samples during the fixed diet
Detailed description
In this study the investigators propose to measure the excretion of urinary oxalate on a fixed diet with controlled amounts of oxalate, in individuals of varying body sizes without history of kidney stones. The 24-hr urinary oxalate excretion on such a low-oxalate normal calcium fixed diet is determined to be an appropriate surrogate for endogenous oxalate synthesis.
Screening phase. The study will enroll 60 individuals without history of kidney stones (30 males/30 females) at the University of Alabama at Birmingham (UAB).
Screening will include blood complete metabolic profile, 24-hr urine specimens collected at home on self-selected diets and anthropometric measurements.
Dietary phase Participants will ingest a low-oxalate (<60 mg/day), normal calcium (1000 mg/day) fixed diet for 4 consecutive days, collect three 24-hr urines after 1 day of dietary equilibration and have a fasted blood draw on day 5.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Normal Individuals | Experimental | Dietary Supplement: Normal IndividualsNormal individuals: no prior history of kidney stones |
Who may qualify
- Ages
- 19 to 70 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Age 19-70 yrs Body Mass Index > 18.5 kg/m2 Normal fasting serum electrolytes on comprehensive metabolic profile Willing to ingest fixed diets
Key exclusion criteria (1 listed)
- Chronic Kidney Disease, estimated glomerular filtration rate < 60 ml/mn/1.73m2 Primary hyperoxaluria Liver, endocrine or renal diseases or any other condition that may influence the absorption, transport or urinary excretion of ions, which will compromise the interpretation of results, including: Cystic fibrosis, Cystinuria, Uric acid stone former, Nephrotic syndrome, Sarcoidosis, Renal tubular acidosis, Primary hyperparathyroidism, Neurogenic bladder, Urinary diversion Pregnancy or breast-feeding Incompatible dietary requirements with the study, food allergies or intolerance to any of the foods in study menus Active malignancy or treatment for malignancy within 12 months prior to screening Utilization of immunosuppressive medication Uncontrolled Hypertension or diabetes
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Normal IndividualsControlled Dietary phase: Low oxalate fixed diet 4 days of fixed normal calorie diet with low oxalate (< 60 mg/day), normal calcium (800-1200 mg/day) | Dietary supplement | Normal Individuals |
Primary outcome
Urinary Oxalate Excretion
Time frame: 3 days on the fixed diet
Mean Urinary oxalate excretion from three 24 hour urine collections on the fixed diet (mg/day)
2 secondary outcomes
Urinary Glycolate Excretion
Time frame: 3 days on fixed diet
Urinary Creatinine Excretion
Time frame: 3 days on the fixed diet
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Sep 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Kyle D Wood, MD principal investigator
University of Alabama at Birmingham
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Normal Individuals in people with Obesity, run by University of Alabama at Birmingham at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 21 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 12 Aug 2024). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Urinary Oxalate Excretion (time frame: 3 days on the fixed diet). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Sep 2026.