Gastric Bypass vs. Diet for Type 2 Diabetes

(RBD-T2D Trial)

No longer recruiting at 2 trial locations

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Washington University School of Medicine

Must not be taking: Metabolic medications

Disqualifiers: Tobacco use, Pregnancy, Organ dysfunction, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

Duration: 6 months

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial compares two weight loss methods—Roux-en-Y Gastric Bypass surgery and a low-calorie diet—to assess their effects on insulin sensitivity and overall metabolism in obese individuals. The focus is on those with Type 2 Diabetes, but some non-diabetics are included in the diet group. Participants should have a Body Mass Index (BMI) between 34 and 55. Those in the surgery group must already be scheduled for this specific bariatric surgery. As an unphased trial, it provides participants a unique chance to contribute to understanding effective weight loss methods and their metabolic impact.

Will I have to stop taking my current medications?

The trial protocol does not specify if you must stop taking your current medications, but it excludes those using medications that might affect metabolic function. It's best to discuss your specific medications with the trial team.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that Roux-en-Y Gastric Bypass (RYGB) surgery is generally safe. Most individuals do not experience serious side effects shortly after the surgery or in the subsequent few years. However, less information exists about its long-term safety.

For the low-calorie diet, safety concerns remain minimal. These diets are commonly used and safe for most individuals. They might cause minor issues like hunger or low energy, but these are usually manageable.

Both treatments aim to assist with weight loss and have been studied for their effects on diabetes. Discussing any concerns with a healthcare provider is important to determine the best option. ^{1 2 3 4 5}

Why are researchers excited about this trial's treatments?

Researchers are excited about these treatments for Type 2 Diabetes because they offer alternative ways to achieve significant weight loss, which is crucial for managing the condition. Unlike standard treatments like medications and lifestyle changes, Roux-en-Y gastric bypass is a surgical procedure that can result in rapid and substantial weight loss by altering the digestive system. On the other hand, the low-calorie diet approach focuses on achieving similar weight loss through a more structured and intensive dietary intervention. Both methods aim for around 16-18% weight loss, providing potentially powerful options for those who may not respond well to conventional treatments.

What evidence suggests that this trial's treatments could be effective for Type 2 Diabetes?

This trial will compare the effectiveness of Roux-en-Y gastric bypass (RYGB) with a low-calorie diet for managing type 2 diabetes (T2D). Research has shown that RYGB is effective for long-term weight loss and T2D management. Studies have found that individuals who undergo RYGB can control T2D for up to 15 years and maintain significant weight loss, often exceeding 20%, for many years. Conversely, a low-calorie diet, which participants in this trial may receive, can aid in weight loss and improve insulin use, but it might not provide the same lasting results as RYGB. While the diet can be effective, RYGB generally leads to higher rates of T2D remission and sustained weight loss. ^{2 3 6 7 8}

Who Is on the Research Team?

Samuel Klein, MD

Principal Investigator

Washington University School of Medicine

Are You a Good Fit for This Trial?

This trial is for obese individuals with or without Type 2 Diabetes, having a BMI between 34-55 kg/m². They must not use tobacco, be pregnant/breastfeeding, have had previous intestinal surgery, significant organ dysfunction (other than diabetes), or take meds affecting metabolism. Exercise should be less than 90 minutes per week.

Inclusion Criteria

I have Type 2 Diabetes.

Your Body Mass Index (BMI) is between 34 and 55.

I am scheduled for RYGB surgery, have a BMI of 34-55, and have Type 2 Diabetes.

Exclusion Criteria

I don't smoke, haven't had intestinal surgery, am not pregnant or breastfeeding, don't have major organ issues, don't take meds affecting metabolism, and exercise less than 90 minutes a week.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants undergo Roux-en-Y gastric bypass surgery or participate in a low-calorie diet intervention to achieve targeted weight loss

6 months

Regular visits for monitoring and assessments

Follow-up

Participants are monitored for changes in insulin sensitivity, beta-cell function, and metabolic profiles after weight loss

6 months

Follow-up assessments before and after weight loss

What Are the Treatments Tested in This Trial?

Interventions

• Low-calorie diet
• Roux-en-Y Gastric Bypass

Trial Overview The study compares the effects of Roux-en-Y Gastric bypass (RYGB) surgery and a low-calorie diet on weight loss and metabolic health in obese patients. It looks at how each method affects insulin sensitivity in the liver and muscles, beta-cell function, and overall metabolic balance over a day.

How Is the Trial Designed?

Group I: Roux-en-Y gastric bypass (RYGB) Experimental Treatment 1 Intervention

Subjects in this group are scheduled to undergo roux-en-Y gastric bypass surgery to obtain approximately 16-18% (with a range of 16-25%) weight loss.

Group II: Low-calorie diet Active Control 1 Intervention

Subjects in this group will participate in a low-calorie diet intervention to obtain approximately 16-18% (with a range of 16-25%) weight loss.

Who Is Running the Clinical Trial?

Washington University School of Medicine

Lead Sponsor

Trials

2,027

Recruited

2,353,000+

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Collaborator

Trials

2,513

Recruited

4,366,000+

Published Research Related to This Trial

In a study of 213 type 2 diabetes patients with a BMI of 25 to 32.5 kg/m2, Roux-en-Y gastric bypass (RYGB) was found to be more effective than medical treatment in achieving significant metabolic improvements, with 23.9% of RYGB patients meeting the triple endpoint compared to only 7.0% in the medical group.

However, RYGB was associated with a higher rate of complications (36 vs. 22), highlighting the need to weigh the benefits of improved metabolic outcomes against the risks of surgical complications when considering treatment options for patients with lower BMI.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Two-year outcomes of Roux-en-Y gastric bypass vs medical treatment in type 2 diabetes with a body mass index lower than 32.5 kg/m2: a multicenter propensity score-matched analysis. Ling, J., Tang, H., Meng, H., et al.[2022]

Citations

1. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/40709782/

Evaluating the Effectiveness and Long-term Outcomes of ... Results: RYGB was associated with more significant long-term weight loss and superior T2DM remission rates. SG had a lower risk of nutritional ...

2. asmbs.org asmbs.org/news_releases/new-study-shows-long-term-effectiveness-of-gastric-bypass-in-treating-type-2-diabetes-and-obesity/

New Study Shows Long-term Effectiveness of Gastric ... Roux-en-Y gastric bypass, a type of weight-loss surgery, kept type 2 diabetes in remission for up to 15 years and most of the weight off for up to 20 years.

3. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0039606024001818

Comprehensive outcomes after Roux-en-Y gastric bypass ... The maximum mean percentage total weight loss achieved at 1 year was 31.5% ± 5.7% and was consistently >20% throughout follow-up. Sustained resolution of ...

4. jamanetwork.com jamanetwork.com/journals/jama/fullarticle/2815401

Long-Term Outcomes of Medical Management vs Bariatric ... Diabetes remission was greater after bariatric surgery (6.2% in the medical/lifestyle group vs 18.2% in the bariatric surgery group; P = .02) at ...

5. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC7317556/

Comparison of the effect of Roux‐en‐Y gastric bypass and ... Seven studies reported data on remission of T2DM 2 to 5 years after bariatric surgery. The overall estimate showed that the remission rates were 132/263 (50%) ...

6. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/38389648/

Comparing Safety and Efficacy Outcomes of Gastric ... RYGB demonstrated significant long-term improvement in diabetes remission and superior total body weight loss compared to SG. While no notable ...

7. jamanetwork.com jamanetwork.com/journals/jamasurgery/fullarticle/2795683

Safety and Effectiveness of Gastric Bypass and Sleeve ... This comparative effectiveness research study investigates if there are differences in weight, diabetes, and safety and utilization outcomes ...

8. thelancet.com thelancet.com/journals/lanepe/article/PIIS2666-7762(25)00222-4/fulltext

Long–term effects of gastric bypass and sleeve ... Long-term data on the efficacy and safety of Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) in people with type 2 diabetes ...