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ObesityRBD-T2DNCT02207777

Weight Loss-Independent Metabolic Effects of Roux-En-Y Gastric Bypass in Diabetes

A study testing Roux-en-Y gastric bypass surgery and Low-calorie diet in people with Obesity and Type 2 Diabetes, run by Washington University School of Medicine at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

For this purpose, we will compare the effects of targeted 16-18% (with a range of 16-25%) weight loss induced by Roux-en-Y Gastric bypass (RYGB) surgery with the same weight loss induced by a low-calorie diet (LCD) on liver and skeletal muscle insulin sensitivity, beta-cell function, and 24-hour metabolic homeostasis… Read more about this study

Who is it for?
Ages 25 to 65 years
Conditions the study is for
Obesity, Type 2 Diabetes
What is being tested?
Roux-en-Y gastric bypass surgery and Low-calorie diet
Could I receive a placebo?
No, everyone receives an active treatment
How many people
65 participants
Where
1 siteUnited States
Study dates
Aug 2014to Mar 2019
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 25 to 65 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • For RYGB group:
  • Scheduled for this bariatric surgery
  • Body Mass Index (BMI) 34-55 kg/m²
  • Type 2 Diabetes
  • Signed informed consent
  • For Low-Calorie Diet group:
Show all 9Show fewer
  • BMI 34-55 kg/m²
  • Type 2 Diabetes and Non-Diabetics
  • Signed informed consent

Who cannot join

  • For both RYGB \& Low-Calorie Diet groups
  • Regular use of tobacco products
  • Previous intestinal resection
  • Pregnant or breastfeeding
  • Evidence of significant organ system dysfunction or disease other than T2D
  • Use of any medication that might, in the opinion of the investigator, affect metabolic function
  • Exercise ≥90 minutes per week

Trial locations and contacts

1 site in 1 country.

United States1 site

  • Washington University School of Medicine

    St Louis, Missouri, 63110

Other trials in United States

About this study

For this purpose, we will compare the effects of targeted 16-18% (with a range of 16-25%) weight loss induced by Roux-en-Y Gastric bypass (RYGB) surgery with the same weight loss induced by a low-calorie diet (LCD) on liver and skeletal muscle insulin sensitivity, beta-cell function, and 24-hour metabolic homeostasis in obese subjects with or without T2D.

Being tested
Roux-en-Y gastric bypass surgery, Low-calorie diet
Keywords
Obesity, Roux-en-Y gastric bypass (RYGB), Type 2 Diabetes, Weight Loss, Low-Calorie Diet
Medical subject headings
Obesity, Diabetes Mellitus, Type 2, Weight Loss

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Roux-en-Y gastric bypass surgeryProcedure or surgery

    A surgical procedure to help subjects lose approximately 16-18% (with a range of 16-25%) of their body weight.

  • Low-calorie dietBehavioural

    Subjects will meet with a dietitian and/or behaviorist over approximately 6 months to lose approximately 16-18% (with a range of 16-25%) of their body weight.

Study groups in NCT02207777
Study groupRoleWhat they receive
Roux-en-Y gastric bypass (RYGB)ExperimentalSubjects 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.
Receives: Procedure: Roux-en-Y gastric bypass surgery
Low-calorie dietActive comparatorSubjects in this group will participate in a low-calorie diet intervention to obtain approximately 16-18% (with a range of 16-25%) weight loss.
Receives: Behavioral: Low-calorie diet

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Changes in hepatic insulin sensitivity

    The outcome will be assessed by hyperinsulinemic-euglycemic-pancreatic-clamp procedure before and after weight loss.

    Measured: 6 months (before and after targeted weight loss)

Secondary outcomes (10)

  1. Changes in skeletal muscle and adipose tissue insulin sensitivity

    The outcome will be assessed by hyperinsulinemic-euglycemic-pancreatic-clamp procedure before and after weight loss.

    Measured: 6 months (before and after targeted weight loss)

  2. Changes in Beta-cell function

    The outcome will be assessed as the product of beta-cell glucose sensitivity (ratio of post-meal insulin secretion rate to post-meal plasma glucose) during mixed-meal test and whole-body insulin sensitivity before and after weight loss.

    Measured: 6 months (before and after targeted weight loss)

  3. Changes in glucose kinetics (glucose concentration and rate of appearance into the systemic circulation) in response to mixed-meal ingestion

    The outcome will be measured by using dual glucose tracer mixed meal metabolic test and serial blood sampling for 4 hours before and after weight loss

    Measured: 6 months (before and after targeted weight loss)

  4. Changes in 24-hour plasma glucose profile

    The outcome will be determined by obtaining serial plasma glucose concentration measurements for 24 hours before and after weight loss

    Measured: 6 months (before and after targeted weight loss)

  5. Changes in 24-hour plasma insulin profile

    The outcome will determined by obtaining serial plasma insulin concentration measurements for 24 hours before and after weight loss

    Measured: 6 months (before and after targeted weight loss)

  6. Changes in 24-hour plasma free fatty acid profile

    The outcome will determined by obtaining serial plasma free fatty acid concentration measurements for 24 hours before and after weight loss

    Measured: 6 months (before and after targeted weight loss)

  7. Changes in body fat mass

    The outcome will be measured by using dual-energy X-ray absorptiometry before and after weight loss

    Measured: 6 months (before and after targeted weight loss)

  8. Changes in intra-abdominal adipose tissue volume

    The outcome will be measured by using magnetic resonance imaging before and after weight loss

    Measured: 6 months (before and after targeted weight loss)

  9. Changes in intrahepatic triglyceride content

    The outcome will be measured by using magnetic resonance imaging before and after weight loss

    Measured: 6 months (before and after targeted weight loss)

  10. Changes in fat free mass

    The outcome will be measured by using dual-energy X-ray absorptiometry before and after weight loss

    Measured: 6 months (before and after targeted weight loss)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted4 Aug 2014 (estimated)
  2. Study startAug 2014
  3. Primary completionMar 2019
  4. Study completionMar 2019

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Non-randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
65 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT02207777
Sponsor's protocol ID
201403065
Other IDs
1R01DK101578
Acronym
RBD-T2D
Status last verified
Jul 2025
First submitted
31 Jul 2014
Last updated
20 Jul 2025
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No

Publications

  • Petersen MC, Yoshino M, Smith GI, Gaspar RC, Kahn M, Samovski D, Shulman GI, Klein S. Effect of Weight Loss on Skeletal Muscle Bioactive Lipids in People With Obesity and Type 2 Diabetes. Diabetes. 2024 Dec 1;73(12):2055-2064. doi: 10.2337/db24-0083.

    PubMed 39264820

  • Samovski D, Smith GI, Palacios H, Pietka T, Fuchs A, Patti GJ, Nawaz A, Kahn CR, Klein S. Effect of Marked Weight Loss on Adipose Tissue Biology in People With Obesity and Type 2 Diabetes. Diabetes Care. 2025 Aug 1;48(8):1342-1351. doi: 10.2337/dc24-2739.

    PubMed 40208704

  • Smith GI, Klein S. Plasma endotrophin levels correlate with insulin resistance in people with obesity. J Clin Invest. 2025 Apr 22;135(12):e190577. doi: 10.1172/JCI190577. eCollection 2025 Jun 16. No abstract available.

    PubMed 40261704

  • Yoshino M, Kayser BD, Yoshino J, Stein RI, Reeds D, Eagon JC, Eckhouse SR, Watrous JD, Jain M, Knight R, Schechtman K, Patterson BW, Klein S. Effects of Diet versus Gastric Bypass on Metabolic Function in Diabetes. N Engl J Med. 2020 Aug 20;383(8):721-732. doi: 10.1056/NEJMoa2003697.

    PubMed 32813948

  • van Vliet S, Koh HE, Patterson BW, Yoshino M, LaForest R, Gropler RJ, Klein S, Mittendorfer B. Obesity Is Associated With Increased Basal and Postprandial beta-Cell Insulin Secretion Even in the Absence of Insulin Resistance. Diabetes. 2020 Oct;69(10):2112-2119. doi: 10.2337/db20-0377. Epub 2020 Jul 10.

    PubMed 32651241

Questions about this trial

What is this clinical trial studying?

A study testing Roux-en-Y gastric bypass surgery and Low-calorie diet in people with Obesity and Type 2 Diabetes, run by Washington University School of Medicine at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 9 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 20 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Changes in hepatic insulin sensitivity (time frame: 6 months (before and after targeted weight loss)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT02207777, which also lists 5 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Jul 2025.

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