Actively Recruiting
The Effects of Bariatric Surgeries on Glucose Metabolism
Led by The University of Texas Health Science Center at San Antonio · Updated on 2025-09-09
200
Participants Needed
2
Research Sites
52 weeks
Total Duration
On this page
Sponsors
T
The University of Texas Health Science Center at San Antonio
Lead Sponsor
N
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Collaborating Sponsor
AI-Summary
What this Trial Is About
Researchers are studying the effects of two types of bariatric surgeries, gastric bypass and sleeve gastrectomy, on how the body controls glucose metabolism. The study focuses on the hormonal and neural factors that affect islet cell response after eating, aiming to understand differences between these surgeries independent of weight loss. This research could help develop new treatments for diabetes and improve blood sugar control in patients who have partial or relapsed diabetes after surgery. Participants will receive one of two drug interventions: Exendin-(9-39) to study the role of GLP-1 on glucose metabolism and insulin secretion after glucose and protein intake, or Atropine to assess how neural activation influences insulin secretion and glucose metabolism. The study is randomized and single-blind, with procedures lasting up to seven hours, during which insulin levels are measured at specific intervals after nutrient ingestion. During the study, participants will undergo detailed monitoring of insulin levels and other metabolic assessments following meal ingestion. The research team will collect data for up to seven hours per session, focusing on changes in glucose metabolism. Participants must be able to visit the clinical research center for these assessments. The study runs until August 2027 and includes adults aged 18 to 65 years.
CONDITIONS
Brief Title
The Effects of Bariatric Surgeries on Glucose Metabolism
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Hypoglycemic Roux-en-Y gastric bypass patients with documented blood glucose levels below 50 mg/dl
- Asymptomatic individuals who have had bariatric surgery
- Healthy individuals without a personal history of diabetes
- Ability to physically come to the clinical research center
You will not qualify if you...
- Active heart, lung, liver, gastrointestinal, or kidney disease
- Unable to give informed consent
- Pregnancy
- Uncontrolled high blood pressure or high cholesterol
- Significant anemia (hemoglobin below 11 g/dL)
- Prisoners or institutionalized individuals
- Type 2 diabetes mellitus
- Serious medical or psychiatric illness developing during recruitment or studies
- Gastric outlet obstruction or severe diarrhea in Roux-en-Y gastric bypass patients
- Personal history of diabetes in healthy non-surgical patients
- History of glaucoma (for atropine administration)
- Uncontrolled hypertension (blood pressure over 140/90) with dyslipidemia
- Use of medications that interact with atropine and cannot be stopped
- Myasthenia gravis
- Brain pathology
- Enlarged prostate in men (for atropine administration)
AI-Screening
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Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - Each study session lasts up to 7 hours with data collected during the session; schedule depends on crossover design timing.
Participants receive two different drug interventions, Exendin-(9-39) and Atropine, in a randomized crossover design to evaluate their effects on glucose metabolism and insulin secretion after nutrient ingestion.
2 to multiple in-person visits depending on crossover schedule
Trial Site Locations
Total: 2 locations
1
Texas Diabetes Institute - University Health System
San Antonio, Texas, United States, 78207
Actively Recruiting
2
South Texas Veterans Health Care System
San Antonio, Texas, United States, 78229
Actively Recruiting
Research Team
M
Marzieh Salehi, MD MS
J
Jennifer Foster, MSN
How is the study designed?
Study Type
INTERVENTIONAL
Masking
SINGLE
Allocation
RANDOMIZED
Model
CROSSOVER
Primary Purpose
OTHER
Number of Arms
2
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