Actively Recruiting
Determine the Contribution of Paracellular GI Oxalate Absorption in Obese and Roux-en-Y Gastric Bypass Kidney Stone Patients
Led by University of Chicago · Updated on 2025-08-19
30
Participants Needed
1
Research Sites
8 weeks
Total Duration
On this page
Sponsors
U
University of Chicago
Lead Sponsor
U
University of Alabama at Birmingham
Collaborating Sponsor
AI-Summary
What this Trial Is About
This research aims to better understand how oxalate, a compound found in many foods, affects the risk of forming kidney stones. It focuses on three groups of people who have formed kidney stones: those who have had Roux-en-Y gastric bypass surgery, obese individuals, and non-obese individuals. The study seeks to learn how much oxalate is absorbed through the digestive system and how this varies among these groups, which may help guide better treatments for kidney stone risk. Participants will follow a very low oxalate diet (50 mg per day) for five days. For the first two days, they will eat a special diet at home. From days 3 to 5, special meals will be delivered to their homes from a research clinic. On days 4 and 5, they will collect 24-hour urine samples. On day 6, participants will visit the research clinic for most of the day to receive a special oxalate-containing liquid and a specially prepared breakfast low in oxalate and citrate. Blood and urine samples will be collected throughout the day. During the study, participants will have their urine oxalate and citrate levels measured before and after the low oxalate diet. The research team will monitor absorption of labeled oxalate and sucralose through urine and blood tests. These measurements will help determine how much oxalate is absorbed from the digestive tract and its role in kidney stone formation. The study lasts about one week, with close monitoring to understand oxalate absorption and kidney stone risk in different patient groups.
CONDITIONS
Brief Title
GI Oxalate Absorption
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Age between 18 and 70 years
- Previous history of Roux-en-Y gastric bypass and at least one calcium-based kidney stone after surgery with urine oxalate above normal (for post-Roux-en-Y group)
- Body mass index (BMI) of 30 or higher with history of at least one calcium-based kidney stone and urine oxalate above normal (for obese group)
- BMI between 18.5 and 29.9 with history of at least one calcium-based kidney stone (for non-obese group)
You will not qualify if you...
- History of colon resection (partial or complete) for post-Roux-en-Y group
- History of duodenal switch bowel surgery for post-Roux-en-Y group
- History of ileal-jejunal bypass surgery for post-Roux-en-Y group
- History of primarily uric acid, cysteine, or struvite kidney stones for post-Roux-en-Y group
- History of bowel surgery for obese and non-obese groups
- History of colon resection for obese and non-obese groups
- History of inflammatory bowel disease (Crohn's disease or Ulcerative Colitis) for obese and non-obese groups
- History of primarily uric acid, cysteine, or struvite kidney stones for obese and non-obese groups
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 5 days
Participants follow a very low oxalate diet, initially managing the diet at home and then receiving special meals delivered from the clinical research center.
Daily at-home diet management with meal delivery from Days 3 to 5
Duration - 1 day
Participants spend a full day at the research clinic where they receive a special oxalate-containing liquid and a low oxalate breakfast, followed by urine and blood collection throughout the day.
1 visit (in-person) with multiple urine collections and 4 blood draws
Trial Site Locations
Total: 1 location
1
University of Chicago Medical Center
Chicago, Illinois, United States, 60637
Actively Recruiting
Research Team
M
Megan Prochaska, MD
E
Elaine Worcester, MD
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
NA
Model
SINGLE_GROUP
Primary Purpose
PREVENTION
Number of Arms
1
Similar Trials
Frequently Asked Questions
Have more questions? Get in touch with our team for quick support
Not the Right Trial for You?
Explore thousands of other clinical trials that might be a better match.
Sign up to get personalized trial recommendations delivered to your inbox.
Already have an account? Log in here