Gut Oxalate Absorption in Calcium Oxalate Stone Disease

NCT06331546 | Recruiting DMC

• 2 other identifiers: IRB300004693-GIAR01DK137784
• 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 absorption of dietary oxalate, 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 and moderately high amounts of oxalate for 5 days at a time
• ingest a soluble form of oxalate and sugar preparations to test gut permeability
• collect urine, blood, stool and breath sample during the fixed diets and the soluble oxalate test

Conditions

Kidney Stone; Kidney Calculi; Urolithiasis; Urolithiasis, Calcium Oxalate; Nephrolithiasis; Nephrolithiasis, Calcium Oxalate; Oxalate Urolithiasis; Oxaluria; Healthy

Outcome Measures

Primary Outcomes (1)

• Net Gastrointestinal absorption of food-bound oxalate

  difference between 24-hour urinary oxalate excretion on the high oxalate diet and the low oxalate diet, normalized to the difference in dietary oxalate composition of the two diets (%)

  4 day

Secondary Outcomes (2)

• Absorption of soluble 13C2-oxalate

  1 day

• Estimated endogenous oxalate synthesis (oxalate mg/day)

  2 days

Study Arms (2)

Idiopathic Calcium Oxalate Kidney Stone Patients

EXPERIMENTAL

Low and High oxalate fixed diets. Soluble oxalate absorption test.

Dietary Supplement: Low-oxalate diet; Dietary Supplement: High-oxalate diet; Other: soluble oxalate gut absorption test

Healthy non-kidney stone forming individuals

ACTIVE COMPARATOR

Low and High oxalate fixed diets. Soluble oxalate absorption test.

Dietary Supplement: Low-oxalate diet; Dietary Supplement: High-oxalate diet; Other: soluble oxalate gut absorption test

Interventions

Low-oxalate diet DIETARY_SUPPLEMENT

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

High-oxalate diet DIETARY_SUPPLEMENT

4 days of fixed eucaloric diet with moderately high oxalate (250-300 mg/day), normal calcium content (600-1000 mg/day)

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

soluble oxalate gut absorption test OTHER

Oral ingestion of 13C2-oxalate and sucralose.

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

Eligibility Criteria

• Age: 18 Years - 70 Years
• Gender Eligibility Details: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• age 18-70 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
• Chronic NSAID use

Sponsors & Collaborators

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

Study Sites (2)

University of Alabama at Birmingham

Birmingham, Alabama, 35294, United States

RECRUITING

UTSW

Dallas, Texas, 75390, United States

ACTIVE NOT RECRUITING

MeSH Terms

Conditions

Kidney Calculi; Urolithiasis; Nephrolithiasis, Calcium Oxalate; Nephrolithiasis; Hyperoxaluria

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

2059756932; 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: Assistant Professor

Study Record Dates

• First Submitted: March 19, 2024
• First Posted: March 26, 2024
• Study Start: April 17, 2024
• Primary Completion (Estimated): December 31, 2030
• Study Completion (Estimated): December 31, 2031
• Last Updated: May 13, 2025

Record last verified: 2025-05

Data Sharing

• IPD Sharing: Will not share

Locations

US (2)