Gastrointestinal Oxalate Absorption in Calcium Oxalate Stone Disease
University of Alabama at Birmingham
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
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 Ston…
Eligibility
- Age range
- 18–70 years
- Sex
- All
- Healthy volunteers
- Yes
Inclusion Criteria: * 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% Exclusion Criteria: * Chronic Kidney Disease stage…
Interventions
- Dietary SupplementLow-oxalate diet
4 days of fixed eucaloric diet with low oxalate (\<60 mg/day), normal calcium content (600-1000 mg/day)
- Dietary SupplementHigh-oxalate diet
4 days of fixed eucaloric diet with moderately high oxalate (250-300 mg/day), normal calcium content (600-1000 mg/day)
- Othersoluble oxalate gut absorption test
Oral ingestion of 13C2-oxalate and sucralose.
Locations (2)
- University of Alabama at BirminghamBirmingham, Alabama
- UTSWDallas, Texas