~3 spots leftby Aug 2025

Gastric Bypass Surgery for Type 2 Diabetes

Recruiting at 1 trial location
MS
Overseen byMarzieh Salehi, MD, MS
Age: 18+
Sex: Any
Travel: May Be Covered
Time Reimbursement: Varies
Trial Phase: Phase < 1
Recruiting
Sponsor: The University of Texas Health Science Center at San Antonio
Disqualifiers: Heart, lung, liver, kidney disease, others
No Placebo Group

Trial Summary

What is the purpose of this trial?

RYGB (roux-en-y gastric bypass) has been reported to reverse type 2 diabetes (T2DM) immediately after surgery before any significant weight loss. In addition, a growing number of patients have been recognized with life-threatening hyperinsulinemic hypoglycemia several years following their surgery. While the mechanisms by which RYGB improves glucose metabolism or alters islet cell function in patients after RYGB are not understood, recent studies suggest that increased secretion of GI hormones, primarily glucagon-like peptide 1 (GLP-1), as well as alteration in neural activity may contribute to enhanced insulin secretion in general, and to a greater extent in patients with hypoglycemia. The proposed research is designed to address the role of RYGB on insulin secretion by evaluating the contribution of stimulatory factors (neural and GI hormone) on islet cell function and the islet cell responsiveness to the physiologic stimulatory factors, in RYGB patients with and without hypoglycemia and non-operated controls.

Do I need to stop my current medications for the trial?

The trial protocol does not specify if you need to stop taking your current medications. However, if you are taking any medication that might interact with atropine and cannot be stopped, you will be excluded from the study.

What data supports the effectiveness of the drug for treating type 2 diabetes?

Research shows that GLP-1 and GIP, components of the drug, help regulate blood sugar and insulin levels, making them effective for treating type 2 diabetes. Additionally, a study on a similar dual receptor agonist in mice demonstrated improved glucose tolerance and reduced obesity-related issues, suggesting potential benefits for humans.12345

How does gastric bypass surgery differ from other treatments for type 2 diabetes?

Gastric bypass surgery is unique because it physically alters the digestive system to help with weight loss and improve blood sugar control, unlike medications that primarily focus on insulin regulation. This surgery can lead to significant and sustained weight loss, which can improve or even resolve type 2 diabetes in some patients.14678

Research Team

MS

Marzieh Salehi, MD, MS

Principal Investigator

Marzieh Salehi

Eligibility Criteria

This trial is for individuals who've had gastric bypass surgery and either have low blood sugar episodes or are symptom-free. It's also open to healthy people without diabetes. Participants must be able to visit Cedars-Sinai Medical Center but can't join if they have certain conditions like an enlarged prostate, glaucoma, serious organ diseases, uncontrolled hypertension or cholesterol, significant anemia, or are pregnant.

Inclusion Criteria

I am healthy, have never had surgery, and do not have diabetes.
I can travel to Cedars-Sinai Medical Center for the study.
I have had low blood sugar levels below 50 mg/dl after gastric bypass surgery.
See 1 more

Exclusion Criteria

You have low hemoglobin levels (less than 11g/dL).
I have myasthenia gravis.
I have not developed a serious illness or psychiatric condition recently.
See 13 more

Trial Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive experimental treatments to evaluate the role of GLP-1 signaling, neural activation, and beta-cell sensitivity to gut hormones

6-8 weeks
Multiple visits for administration of treatments and monitoring

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

Treatment Details

Interventions

  • Atropine (Other)
  • Exendin-(9-39) (Other)
  • GLP-1 and GIP (Hormone Therapy)
Trial OverviewThe study investigates how factors like hormones and nerves affect insulin release after gastric bypass surgery. It involves giving participants drugs such as Exendin-(9-39), Atropine, GLP-1, and GIP to see their effect on insulin secretion in those with and without post-surgery hypoglycemia compared to non-operated controls.
Participant Groups
3Treatment groups
Experimental Treatment
Group I: atropineExperimental Treatment1 Intervention
To evaluate the effect of neural activation on insulin secretion and glucose metabolism
Group II: GLP-1 and GIPExperimental Treatment1 Intervention
to evaluate the beta-cell sensitivity to different doses of exogenous gut hormones
Group III: Exendin-(9-39)Experimental Treatment1 Intervention
To evaluate the role of GLP-1 signaling in glucose tolerance and insulin secretion

Find a Clinic Near You

Who Is Running the Clinical Trial?

The University of Texas Health Science Center at San Antonio

Lead Sponsor

Trials
486
Recruited
92,500+
Dr. Andrew Masica profile image

Dr. Andrew Masica

The University of Texas Health Science Center at San Antonio

Chief Medical Officer

MD from Indiana University School of Medicine

Dr. Taylor Eighmy profile image

Dr. Taylor Eighmy

The University of Texas Health Science Center at San Antonio

Acting President

PhD in Civil Engineering from the University of New Hampshire

Findings from Research

GLP-1-based therapies are effective for treating type 2 diabetes (T2D) and have shown a good safety profile, especially with long-acting analogs that can also be used in combination with insulin.
Recent research highlights that GLP-1 secretion increases after bariatric surgery, contributing to weight loss and diabetes remission, while GIP has important effects on bone metabolism but is not suitable for T2D therapy.
Glucagon-like peptide-1 and gastric inhibitory polypeptide: new advances.Gallwitz, B.[2022]
In a study involving 20 critically ill patients, the addition of glucose-dependent insulinotropic polypeptide (GIP) to glucagon-like peptide-1 (GLP-1) did not enhance glucose-lowering effects or insulin responses during nutrient infusion.
While GIP did cause a slight increase in glucagon levels before nutrient delivery, it ultimately did not contribute to improved glucose control in patients experiencing acute hyperglycemia.
The effect of exogenous glucose-dependent insulinotropic polypeptide in combination with glucagon-like peptide-1 on glycemia in the critically ill.Lee, MY., Fraser, JD., Chapman, MJ., et al.[2021]
Tirzepatide, approved in 2022, is a novel treatment for type 2 diabetes that acts on both GLP-1 and GIP pathways, showing significant efficacy in lowering blood sugar levels and promoting weight loss in various patient groups.
Clinical trials, including the SURPASS and SURMOUNT studies, indicate that tirzepatide has a safety profile similar to traditional GLP-1 receptor agonists, with common gastrointestinal side effects, making it a promising option for patients needing better glycemic and weight management.
Tirzepatide: Clinical review of the "twincretin" injectable.Krauss, Z., Hintz, A., Fisk, R.[2023]

References

Glucagon-like peptide-1 and gastric inhibitory polypeptide: new advances. [2022]
The effect of exogenous glucose-dependent insulinotropic polypeptide in combination with glucagon-like peptide-1 on glycemia in the critically ill. [2021]
Tirzepatide: Clinical review of the "twincretin" injectable. [2023]
GIP1-39, a novel insulinotropic peptide form and aspects on its mechanism of action. [2018]
An oral GLP-1 and GIP dual receptor agonist improves metabolic disorders in high fat-fed mice. [2022]
Effects of atropine on GIP-induced insulin and pancreatic polypeptide release in man. [2019]
Differential incretin effects of GIP and GLP-1 on gastric emptying, appetite, and insulin-glucose homeostasis. [2022]
GIP analogues and the treatment of obesity-diabetes. [2021]