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GI Oxalate Absorption
Determine the Contribution of Paracellular GI Oxalate Absorption in Obese and Roux-en-Y Gastric Bypass Kidney Stone Patients
Who can join
Ages 18 to 70 · All sexes
Full eligibility criteria
Inclusion Criteria: Post-Roux-en-Y gastric bypass stone formers: * Age 18-70 * Previous history of Roux-en-Y gastric bypass * History of at least one calcium-based kidney stone after surgery * Pre-protocol urine oxalate above the lab normal range (50mg/day) Obese stone formers: * Age 18-70 * Body mass index (BMI) \>=30kg/m2 * History of at least one calcium-based kidney stone * Pre-protocol urine oxalate above the lab normal range (50mg/day) Non-obese stone formers: * Age 18-70, BMI between 18.5-29.9 kg/m2 * History of at least one calcium-based kidney stone Exclusion Criteria: Post-Roux-en-Y gastric bypass stone formers: * History of colon resection (partial or complete) * History of duodenal switch bowel surgery * History of ileal-jejunal bypass surgery * History of primarily uric acid, cysteine, or struvite stones Obese and non-obese stone formers: * History of bowel surgery * History of colon resection * History of inflammatory bowel disease (Crohn's disease, Ulcerative Colitis) * History of primarily uric acid, cysteine, or struvite stones
About the study
This study aims to learn more about how oxalate, a compound found in many foods, may affect a person's chances of forming kidney stones. Active participation in this study will last for around one week.
For the first two days, subjects will be asked to eat a special diet at home. From Days 3-5, they will eat special meals delivered to their home from a research clinic at the University of Chicago. They will also collect 24-hour urine samples at home on Days 4 and 5. On Day 6, they will come in to the research clinic at the University of Chicago in Hyde Park, where they will spend most of the day. They will receive a special liquid that contains oxalate, and we will have them eat a specially prepared breakfast that is low in oxalate and citrate.
What is being tested
- Special low-oxalate diet followed by all-day visit to University of Chicago research clinic (other)
Sponsor: University of Chicago · Participants: 30 · Started: Jan 25, 2023
Contact the study team
- Megan Prochaska, MD · Phone: 773-702-1000
- Elaine Worcester, MD · Phone: 773-702-3630
Official record on ClinicalTrials.gov — NCT05356000
Locations in the U.S.
| Illinois | University of Chicago Medical Center, Chicago |
Conditions
From ClinicalTrials.gov, data retrieved Oct 2, 2026. Each study sets its own eligibility; the study team decides who can join.