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Study of Metformin Treatment to Maintain Type 2 Diabetes Remission in Patients After Bariatric Surgery

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This study focuses on patients who have achieved Type 2 Diabetes remission after undergoing bariatric surgery. The research aims to determine if the medication metformin can help maintain diabetes-free status longer compared to standard care after weight loss surgery. Bariatric surgery refers to surgical procedures that help with weight loss by making changes to the digestive system, specifically through procedures called gastric bypass or sleeve gastrectomy.

The study will compare two groups of participants over three years. One group will receive metformin treatment, while the other group will receive standard care without metformin. The medication will be taken by mouth, with a maximum daily dose of 1700 mg. Participants will have regular check-ups to monitor their health status throughout the study period.

During the study, various health measurements will be taken, including blood sugar levels, weight changes, and overall health status. The research will also look at how the treatment affects quality of life and examine changes in digestive system bacteria. This information will help understand the long-term benefits of using metformin after weight loss surgery to prevent diabetes from returning.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial assessment

    Your participation begins 12 to 36 months after having bariatric surgery (gastric bypass or sleeve gastrectomy).

    A medical assessment will confirm your eligibility based on your blood sugar levels (HbA1c less than 6.5%) and the fact that you haven't used diabetes medications in the past three months.

  2. Step 2

    Treatment phase start

    You will be assigned to one of two groups: either receiving metformin treatment or following standard care without additional medication.

    If assigned to the metformin group, you will receive oral medication to take as prescribed.

  3. Step 3

    Regular monitoring - Year 1

    Medical checks will assess your progress through blood tests measuring:

    - Blood sugar levels

    - Nutritional levels (iron, vitamins, calcium)

    - General health indicators

    You will complete a quality of life questionnaire.

    A stool sample will be collected to analyze gut bacteria.

  4. Step 4

    Continued monitoring - Year 2

    Similar medical assessments continue through the second year.

    Your weight and body mass index (BMI) will be tracked.

    Blood tests will continue to monitor your health status.

  5. Step 5

    Final assessment - Year 3

    Final comprehensive medical evaluation includes:

    - Blood sugar level testing

    - Weight and BMI measurements

    - Nutritional status assessment

    - Quality of life questionnaire

    - Final stool sample collection

    The study concludes after this three-year period.

Who can join the trial?

7 criteria

  • Age between 18 and 70 years old
  • Must have undergone bariatric surgery (either gastric bypass or sleeve gastrectomy - surgical procedures to help with weight loss) between 12 to 36 months before joining the study
  • Must have previously had Type 2 Diabetes and either:
    • Used at least one diabetes medication before bariatric surgery, or
    • Had an HbA1c (blood test measuring average blood sugar levels) of 6.5% or higher before surgery
    • Current HbA1c must be below 6.5% at the time of joining the study
    • Must not have taken any diabetes medications in the past 3 months
    • Must be willing and able to provide written informed consent to participate in the study

Who cannot join the trial?

13 criteria

  • Age below 18 or above 64 years
  • Currently having active Type 2 Diabetes without remission after bariatric surgery (weight loss surgery)
  • Not having undergone bariatric surgery
  • Current pregnancy or planning to become pregnant
  • Known allergies or intolerance to metformin (a diabetes medication)
  • Severe kidney problems (as metformin is processed by the kidneys)
  • Severe liver disease
  • History of lactic acidosis (a serious condition where lactic acid builds up in the blood)
  • Current participation in other clinical trials
  • Inability to provide informed consent
  • Any condition that could interfere with study participation as determined by the study doctor
  • History of alcohol or substance abuse
  • Mental health conditions that could affect compliance with the study protocol
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Investigated drugs

Metformin is a commonly prescribed diabetes medication that helps control blood sugar levels. It works by improving how your body responds to insulin and reducing the amount of sugar your liver produces. In this trial, it is being studied to see if it can help maintain diabetes remission in patients who have undergone bariatric surgery. Bariatric surgery often helps patients achieve diabetes remission, and this medication is being tested to potentially extend this benefit. Bariatric Surgery (BS) is a surgical procedure that helps with weight loss by making changes to your digestive system. While not a medication, it is a key therapeutic intervention in this trial. The surgery can help people lose weight and often leads to improvement or remission of type 2 diabetes.

What is already known about the treatment

Metformin – An oral antidiabetic medication taken in tablet form that helps control blood sugar levels in patients with type 2 diabetes. It belongs to the biguanide class of drugs and works by reducing glucose production in the liver, decreasing intestinal absorption of glucose, and improving insulin sensitivity in body tissues. The medication is widely recognized as a first-line treatment for type 2 diabetes and has been extensively studied in clinical trials, including its potential benefits for patients who have undergone bariatric surgery. Metformin is particularly notable for its long-established safety profile and effectiveness in maintaining diabetes remission, with additional benefits including minimal risk of hypoglycemia and potential positive effects on body weight management.

Investigated diseases

  • Type 2 Diabetes

    A metabolic disorder characterized by high blood sugar levels due to the body's ineffective use of insulin or insufficient insulin production. The condition develops gradually, often beginning with insulin resistance, where body cells don't respond effectively to insulin. Over time, this leads to consistently elevated blood glucose levels, affecting how the body processes sugar. The disease typically appears in adults and is often associated with lifestyle factors and genetic predisposition. Common manifestations include increased thirst, frequent urination, fatigue, and slow healing of wounds. The condition can progress over years, with varying degrees of severity.

  • Post-Bariatric Surgery Diabetes Remission

    A condition where diabetes symptoms improve or disappear following weight-loss surgery. This state occurs when blood sugar levels return to normal ranges without the need for diabetes medications after bariatric surgery. The improvement can be partial or complete, depending on blood sugar control levels. The remission may happen gradually as the body adjusts to the changes following surgery. The condition requires ongoing monitoring of blood sugar levels to confirm sustained improvement.

Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-516409-22-00Protocol codeP170901JEstimated enrolment126 patientsSponsorAssistance Publique Hopitaux De Paris

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On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).