University of Alabama at Birmingham
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
In this study the investigators propose to measure the production of oxalate by the body (endogenous oxalate synthesis), after equilibration on a low oxalate diet (\<60 mg oxalate/day, 600-800 mg calcium/day) and estimate the importance of vitamin C and glycolate metabolism to oxalate production in both Calcium Oxalate Kidney Stone patients and matched controls by oral dosings of those two substances. 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…
Inclusion Criteria: * 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% Exclusion Criteria: * Chronic Kidney Disease stage…
Low-oxalate diet 4 days of fixed eucaloric diet with low oxalate (\<60 mg/day), normal calcium content (600-1000 mg/day)
Oral 13C-glycolate dosing (0.5 mg/kg)
Oral 13C- ascorbic acid dosing (0.75 mg/kg)