Trials / Recruiting

RecruitingNCT06331546

Gut Oxalate Absorption in Calcium Oxalate Stone Disease

Gastrointestinal Oxalate Absorption in Calcium Oxalate Stone Disease

Status: Recruiting
Phase: N/A
Study type: Interventional
Enrollment: 80 (estimated)

Sponsor: University of Alabama at Birmingham · Academic / Other
Sex: All
Age: 18 Years – 70 Years
Healthy volunteers: Accepted

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

Detailed description

In this study the investigators propose to measure the net gastrointestinal absorption of oxalate both by food-bound oxalate, using low- (\<60 mg/day) and high- (250-300 mg/day) oxalate diets (600-800 mg daily calcium in both), and by the soluble 13C2-oxalate oral test in both Calcium Oxalate Kidney Stone patients and matched controls. Phase 1. Screening and low-oxalate diet 24-hr urinary excretions. Between the University of Alabama at Birmingham (UAB) and the University of Texas Southwestern Medical Center (UTSW), the study will enroll 40 subjects with idiopathic Calcium Oxalate Kidney Stone (20 Males/20 Females) and 40 non-kidney stone forming controls (20 Males/20 Females). Participants in the two groups will be matched for age (within 10 yrs) and gender. Screening will include blood complete metabolic profile and two 24-hr urine specimens collected at home on self-choice diets and anthropometric measurements. Participants will then ingest the controlled low-oxalate (\<60 mg/d) diet for 5 consecutive days and collect two 24-hr urines after 2 days of dietary equilibration. Phase 2. 13C2-Oxalate gut absorption tests. On Day 5, participants will arrive after an overnight fast in the research unit to undergo the 13C2-oxalate absorption test. After a 1-hour baseline urine collection, they will ingest an oral load containing 100 mg 13C2-oxalate and 1 g sucralose, dissolved in bottled water. For the next 9 hrs, blood and urine will be collected hourly, and breath as more time points. They will remain on the fixed diet for 24 hrs with a breakfast 2 hours after the load, lunch 6 hrs post-load, and dinner at home 12 hrs post-load. They will collect the remainder of their 24-hr urine at home and the totality of the stool eliminated during the first 24 hrs after the load using kits provided. Phase 3. High-oxalate diet 24-hr urinary excretions. After a minimum of 1 week wash-out period, during which participants will eat freely, participants will consume the high oxalate (250-300 mg/day) diet for the next 4 days. Two 24-hr urine specimens will be collected after 2 days of equilibration and a fasting blood draw on the morning of Day 5. .

Conditions

Interventions

Type	Name	Description
DIETARY_SUPPLEMENT	Low-oxalate diet	4 days of fixed eucaloric diet with low oxalate (\<60 mg/day), normal calcium content (600-1000 mg/day)
DIETARY_SUPPLEMENT	High-oxalate diet	4 days of fixed eucaloric diet with moderately high oxalate (250-300 mg/day), normal calcium content (600-1000 mg/day)
OTHER	soluble oxalate gut absorption test	Oral ingestion of 13C2-oxalate and sucralose.

Timeline

Start date: 2024-04-17
Primary completion: 2030-12-31
Completion: 2031-12-31
First posted: 2024-03-26
Last updated: 2025-05-13

Locations

2 sites across 1 country: United States

Source: ClinicalTrials.gov record NCT06331546. Inclusion in this directory is not an endorsement.