A Phase 4 interventional study of GLP-1 receptor agonist in Morbid Obesity, Metabolic Syndrome and Diabetes Mellitus, sponsored by University of Missouri-Columbia. Recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-21.
Sponsored by University of Missouri-Columbia · Phase 4, Interventional, and Treatment
Glucagon-like peptide 1 (GLP-1) is a hormone that helps regulate blood glucose levels through improved insulin sensitivity and release of insulin from the pancreas, control hunger, induce satiety and plays a role in the metabolic health of a person. GLP-1 receptor agonists (GLP1-RAs) have been shown to be effective in achieving weight loss in patients with type 2 diabetes while improving blood glucose control. Bariatric surgical procedures have been shown to be effective in treating obesity as well as superior to best medical therapy for treatment of diabetes not just through restriction of calories but also through a positive impact in modifications of gut hormones, changes in circulating bile acids, modifications in the gut microflora as well as other undefined mechanisms. The combined benefits of GLP1-RAs with bariatric surgery have only been studied to a limited effect. In this randomized trial, the effects of continuation or discontinuation of GLP1-RA therapy in patients undergoing bariatric surgery will be determined. We will compare changes in weight, metabolic determinants including circulating bile acids and gut microbiome, psychological determinants of eating behavior, and adverse side effects in patients who continue vs discontinue therapy. Given differences in metabolic and clinical outcomes in patients undergoing vertical sleeve gastrectomy (VSG) and Roux-en-Y gastric bypass (RYGB), both surgical groups will be examined. The study will be conducted at a high volume bariatric surgical program where patients will undergo randomization at the time of final clinic visit prior to surgery to continue or discontinue GLP1-RA. It is hypothesized that participants who continue GLP1-RA therapy after bariatric surgery will lose more weight with improved blood glucose control than those who discontinue therapy. Furthermore, changes in gut microbiome and circulating bile acids, known determinants of metabolic health, will be modified to a differential extent in those who are on GLP1-RAs vs those where GLP1-RAs are discontinued. Understanding the role these medications play in not only clinical outcomes after metabolic surgery but potential metabolic mechanisms by which surgery improves patient's metabolic health could help people with obesity and type 2 diabetes make informed decisions about their treatment options as well as advise providers on the continuation of these medications in the perioperative and postoperative period.
Preliminary Work To date we have established a randomized controlled clinical trial where we are comparing groups of patients with variable lengths of biliopancreatic limb lengths during gastric bypass. VSG patients serve as a control surgical group, and we have gathered both serum and stool in over 200 patients. We have collaborated with both the institutional metagenomics and proteomics centers to process samples and evaluate bile acid synthesis and stool microbiome content. This trial has successful IRB approval for the project through the University of Missouri-Columbia IRB (#2058104) as well as registered the study with clinicaltrials.gov (NCT04841057).
Recruitment and Randomization:
Randomization of patients and surgical technique. A total of two groups will be utilized. Eligible patients will include those taking a GLP-1 agonist at the time of surgery. These patient will be randomized to either continuation of the GLP-1 agonist or discontinuation of the GLP-1 agonist. Surgical patients will include those undergoing sleeve gastrectomy, gastric bypass, duodenal switch, or revisional surgery.
Recruitment Site Weight Management and Metabolic Center Preoperative and post-operative weight loss surgery patients as well as non-surgical weight management patients are seen by providers at the Weight Management and Metabolic Center, a part of MU Health Care. Patients will undergo standard screening for medical and surgical history per any preoperative weight loss surgery patient. Per our standard protocol all patients will have a full set of nutrition labs which includes basic labs including complete blood count and complete metabolic profile as well as vitamin and nutrient labs.
Consent Process:
Each patient will be approached before the weight loss or bariatric surgery or during their care for medical weight loss or when being evaluated for non-weight loss surgery. In addition, Written Consent and HIPPA form consent will be provided for the patient to review, and one of the research staff listed on the local IRB will be available to answer any questions after the patient has sufficient time to review the consent.
Number of anticipated subjects:
Sample size for randomization to two groups will be 150 patients. This is based on power analysis to have an 80% power to detect a difference in percentage of excess body weight loss with a probability of a Type 1 error rate of 5%. This will provide adequate patients given several different procedures that will be performed on patients in each group and an attrition rate of 30% who do not follow through with either follow-up appointments or adherence to their randomization status/group.
Sample size was determined based on previously published literature. This is an appropriate number to demonstrate a statistical difference in weight loss, the primary end goal.
Study Procedures/ Design/ Treatment Plan:
Patients will be recruited for approximately 5 years to gather the appropriate sample size. Because each patient will have samples collected for 5 years, it will be approximately 10 years from last patient enrolled until study is completed.
Surgical Procedures Each patient will decide which surgical procedure he/she desires after the initial consultation with the surgeon.
A gastric bypass will be performed using our standard technique. In brief, all procedures will be performed laparoscopically as is standard practice. Specifically, at our institution, the gastric pouch will be constructed with a linear stapler approximately 5 cm long and 3 cm wide. The gastrojejunostomy anastomosis will be constructed either with a 25 mm circular stapler or a linear stapler. The linear stapler common gastroenterotomy will be closed in a running 2 layer manner to narrow to approximately 13-15 mm. The jejunojeunostomy will be created with a liner stapler after creation of BPL length of 100 cm and an alimentary limb length of 125 cm which will be connected to the gastric pouch via the gastrojejunostomy. The remaining small bowel, which will represent the common small bowel channel will also be measured. Measurements will be achieved in a standard manner.
Patients undergoing a sleeve gastrectomy will undergo a procedure to laparoscopically resect and remove approximately 80% by volume of the outer portion of the stomach. At our institution, specifically the sleeve gastrectomy is performed using a bougie as an intraluminal template for sizing purposes. The bougie is either 36 or 40 French per our usual practice.
Medication Use Protocol
Preoperative and Postoperative Visits
Specimen Collection
Clinical Data Collection
All patients will be performed for patients per routine care provided through metabolic and bariatric clinic. Regarding GLP-1 agonist therapy there is currently no standard of care whether to continue or discontinue their use after bariatric surgery.
Data Safety Monitoring Plan
The following additional variables will be included in the prospective database at the following follow-up visits (3 month, 6 months, 12 month, 24 months, 36 months, 48 months, and 60 months follow-up) and used to monitor for complications or adverse events:
941 studies on the registry are indexed under Obesity, Morbid; 163 are open to participants now.
This study's planned enrollment of 150 is above the median of 62 across 602 interventional studies indexed under Obesity, Morbid.
Browse Obesity, Morbid studies →University of Missouri-Columbia is the lead sponsor of 365 studies on the registry; 69 are open to participants now.
Of its 43 completed or terminated interventional studies of FDA-regulated products, 29 (67%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
5. Taking a GLP-1 agonist as part of their routine medical care apart from any planned surgical procedure. The current standard of care regarding continuation or discontinuation of GLP-1 agonists has not been established and is at the discretion of members of the patient's medical team but to be included the patient and medical care team must be willing to continue or discontinue the GLP-1 agonist after surgery depending on the randomized group.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
This cohort will consist of patients undergoing bariatric surgery who are currently receiving a GLP-1 Agonists for weight loss and/or diabetes management, that will be maintained on their preoperative dose of GLP-1 agonist following their bariatric surgery. This includes semaglutide, tirzepitide, among others. The dosage will be variable, but will be the same dose the patient is on prior to the bariatric surgery. Duration will be one of the aims of the study.
Drug: GLP-1 receptor agonist
This cohort will consist of patients undergoing bariatric surgery who are currently receiving a GLP-1 Agonist for weight loss and/or diabetes management that will be required to stop taking their preoperative dose of GLP-1 agonist following their bariatric surgery. Dosage preoperative will be variable based on what the patient is currently taking, as well as the medication being taken.
Randomized to continue or discontinue GLP-1 receptor agonists after bariatric surgery
Also known as: GLP-1 agonists
This study also gives Semaglutide. No intervention listed here names it: that was found by reading the record.
Effect of GLP1-RA on weight loss
To investigate the effects of GLP1-RAs on weight loss reflected as change in BMI (kg per meter sq) in patients undergoing metabolic surgery
Time frame: 6 months
Effect of GLP1-RA on circulating bile acids and metabolites
Determine the impact of GLP1-RA on circulating bile acids and other metabolites
Time frame: 6 months
Effector of GLP1-RA on gut microbiome diversity
To determine the impact of GLP1-RAs after bariatric surgery on changes in the gut microbiome
Time frame: 6 months
Effect of GLP1-RA on satiety and hunger
To assess the impact of GLP-1 agonists on satiety and hunger in patients who undergo metabolic surgery. Scale will be a validated scoring system, "Daily Eats Questionnaire," with scores ranging from 0-10, with a 0 indicating no hunger, and 10 indicating extreme hunger
Time frame: 6 months
Effect of GLP1-RA on Glycemic control
HGBA1C levels will be measured at 3 and 6 months after surgery to determine if HGBA1C drops more in patients maintained on GLP1-RA
Time frame: 6 months
Plan to share: Undecided — We will be collecting data on the participants in the study including glycemic control and weight loss. We will also including information on specimens which include bile acids, and microbiome. While at this time we do not have any plans to make individual participant data (IPD) available to other researchers, we are undecided.
Started Feb 2024 (actual). Primary completion is estimated for Jul 2028, 53 months after the start.
Of 28 phase 4 interventional studies under Obesity, Morbid, half reached primary completion within 30 months of starting (the median), counting those still running; a quarter within 12 and three quarters within 43. This study's planned 53 months is above that.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Studies of the drugs tested here: GLP-1 Mimetic · Semaglutide
University of Missouri-Columbia →