Endogenous Oxalate Synthesis in Idiopathic Calcium Oxalate Kidney Stone Disease

NCT06989320 | Recruiting DMC

• 2 other identifiers: IRB300014279-OSSR01DK137784
• Study Type: interventional
• Target: 80
• Locations: 1 country
• Sites: 2

Brief Summary

The goal of this clinical trial study is to test if patients with idiopathic calcium oxalate kidney stones have an increased production of oxalate by the body, which would lead to increased urinary excretion of oxalate. The study will recruit adult patients with a history of calcium oxalate kidney stones and healthy volunteers without kidney stones. Participants will ingest fixed diets containing low amounts of oxalate for 5 days ingest a soluble form of glycolate and vitamin C collect urine, blood, stool during the dietary and oral dosing portions of the study and also collect breath sample during the oral glycolate test

Conditions

Kidney Stones; Kidney Calculi; Urolithiasis; Urolithiasis, Calcium Oxalate; Nephrolithiasis; Nephrolithiasis, Calcium Oxalate; Oxalate Urolithiasis; Healthy; Healthy Volunteer

Keywords

oxalate synthesis

Outcome Measures

Primary Outcomes (1)

• Estimated endogenous oxalate synthesis (oxalate mg/day)

  Basal rate of endogenous oxalate synthesis estimated by repeat fasted hourly urine collections (mg/day)

  1 day

Secondary Outcomes (2)

• 24-hour urinary oxalate excretion on low oxalate diet

  2 days

• contribution of ascorbic acid breakdown to urinary oxalate excretion

  2 days

Other Outcomes (1)

• Contribution of glycolate metabolism to urinary oxalate

  1 day

Study Arms (2)

Idiopathic Calcium Oxalate Kidney Stone Patients

EXPERIMENTAL

Low oxalate fixed diets. oral glycolate and ascorbic acid administration

Dietary Supplement: Low-oxalate diet and glycolate dosing; Dietary Supplement: Oral glycolate dosing; Dietary Supplement: Oral 13C- ascorbic acid dosing

Healthy non-kidney stone forming individuals

ACTIVE COMPARATOR

Low oxalate fixed diets. oral glycolate and ascorbic acid administration

Dietary Supplement: Low-oxalate diet and glycolate dosing; Dietary Supplement: Oral glycolate dosing; Dietary Supplement: Oral 13C- ascorbic acid dosing

Interventions

Low-oxalate diet and glycolate dosing DIETARY_SUPPLEMENT

Low-oxalate diet 4 days of fixed eucaloric diet with low oxalate (\<60 mg/day), normal calcium content (600-1000 mg/day)

Healthy non-kidney stone forming individuals; Idiopathic Calcium Oxalate Kidney Stone Patients

Oral glycolate dosing DIETARY_SUPPLEMENT

Oral 13C-glycolate dosing (0.5 mg/kg)

Healthy non-kidney stone forming individuals; Idiopathic Calcium Oxalate Kidney Stone Patients

Oral 13C- ascorbic acid dosing DIETARY_SUPPLEMENT

Oral 13C- ascorbic acid dosing (0.75 mg/kg)

Healthy non-kidney stone forming individuals; Idiopathic Calcium Oxalate Kidney Stone Patients

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• age 18-80 yrs
• Body Mass Index \> 18.5 kg/m2
• Normal fasting serum electrolytes on comprehensive metabolic profile
• Willing to ingest fixed diets
• Willing to stop supplements (vitamins including vitamin C, calcium (citrate or carbonate) and other minerals, herbal supplements, nutritional aids, probiotics) for 2 weeks before start and during study.
• For stone formers: first time or recurrent Calcium Oxalate stone former. Composition of most recent stone ≥ 50% calcium oxalate if available, uric acid component \<20%

You may not qualify if:

• Chronic Kidney Disease stage 4-5
• Primary hyperoxaluria, Enteric (secondary) hyperoxaluria
• Liver, bowel, endocrine or renal diseases (other than idiopathic Calcium Oxalate kidney stones) 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, Celiac disease, Cystinuria, Uric acid stone former, Nephrotic syndrome, Sarcoidosis, Renal tubular acidosis, Primary hyperparathyroidism, Neurogenic bladder, Urinary diversion, Chronic diarrhea, Bariatric surgery, Inflammatory bowel disease
• 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
• Diabetes type 1

Sponsors & Collaborators

• University of Alabama at Birmingham: lead
• University of Texas, Southwestern Medical Center at Dallas: collaborator
• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK): collaborator

Study Sites (2)

United States, Alabama University of Alabama at Birmingham

Birmingham, Alabama, 35294, United States

RECRUITING

University of Texas South Western Medical Center

Dallas, Texas, 75390, United States

NOT YET RECRUITING

MeSH Terms

Conditions

Kidney Calculi; Urolithiasis; Nephrolithiasis, Calcium Oxalate; Nephrolithiasis

Condition Hierarchy (Ancestors)

Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Urinary Calculi; Male Urogenital Diseases; Calculi; Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms

Study Officials

• Sonia Fargue, PhD

  University of Alabama at Birmingham

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Sonia Fargue, PhD

CONTACT

205-975-6932; sfargue@uabmc.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate professor

Study Record Dates

• First Submitted: May 9, 2025
• First Posted: May 25, 2025
• Study Start: May 27, 2025
• Primary Completion (Estimated): December 31, 2030
• Study Completion (Estimated): December 31, 2031
• Last Updated: May 31, 2025

Record last verified: 2025-05

Data Sharing

• IPD Sharing: Will not share

Locations

US (2)