Effect of Bariatric Surgery on Mechanisms of Type 2 Diabetes (STAMPEDEII)

The purpose of this study is to determine the effects of bariatric surgery on blood sugar control and underlying mechanisms that contribute to type 2 diabetes in men and women with a BMI between 27 and 42. Sixty subjects will be randomized to either undergo the roux-en-y gastric bypass operation or intensive medical, dietary and exercise management.

Obesity and type 2 diabetes mellitus (T2DM) are two of the greatest public health problems of the 21st century. Lifestyle changes and pharmacotherapy, which are mainstay treatments for T2DM have had limited success. More intensive lifestyle weight management such as in the Look AHEAD trial reported an 8.6% weight loss after 1 year, while the Diabetes Prevention Program reported a 7% weight loss after 2 years, and a 58% decrease in the risk of developing T2DM. In contrast,we have observed a 31% weight loss together with 83% remission of T2DM in severely obese patients after Roux-en-Y gastric bypass (RYGB) surgery. However, direct evidence of the glycemic benefits of bariatric surgery from randomized control trials is lacking; there is no clear consensus that RYGB surgery is a good treatment option for moderately obese T2DM patients; and the mechanisms responsible for reversing T2DM after surgery remain unclear but may involve pancreatic insulin secretion and skeletal muscle and hepatic insulin resistance. The objective of this application is to evaluate the effects of RYGB surgery on glycemic control and underlying mechanisms that contribute to T2DM in obese subjects (BMI: 30-40 kg/m2). Our central hypothesis is that RYGB surgery will reduce hyperglycemia via reversal of beta-cell dysfunction and decrease hepatic and peripheral insulin resistance. The approach requires a 12-month randomized controlled trial. The rationale is based on data showing that RYGB lowers fasting and postprandial glucose, and increases the GLP-1 response to a meal. However, the therapeutic efficacy of RYGB surgery in obesity-related T2DM needs to be demonstrated in a randomized trial.

Medical Treatment: Comprehensive medical management of diabetes including medications, diet intervention, lifestyle modification, exercise regimen

The working hypothesis for this aim is that significantly more obese T2DM patients who undergo RYGB surgery will achieve glycemic control based on a primary endpoint of an HbA1c ≤ 6.5% at 12 months, than patients managed by intensive medical therapy.

Determine the effects of gastric bypass surgery on pancreatic beta cell function and incretin hormone secretion in obese type 2 dm patients

The working hypothesis for this aim is that a primary physiological link between obesity and T2DM is specific to beta-cell dysfunction; RYGB will reverse beta-cell dysfunction by increasing postprandial incretin secretion.

Inclusion Criteria: candidate for general surgery 18 to 60 years old BMI 27-43 type 2 diabetes willing to participate in either study arm understand and comply with requirements of each arm not pregnant willing to use reliable birth control for duration of study Exclusion Criteria: prior bariatric surgery of any type prior complex abdominal surgery abdominal, thoracic, pelvic, obstetrical surgery within last 6 months significant cardiovascular disease kidney disease with a creatinine greater than or equal to 1.8 mg/dl chronic liver disease except for NAFLD/NASH celiac, malabsorptive, inflammatory bowel disorders psychiatric disorders requiring 3 or more medications pregnancy cancer except squamous or basal cell skin cancer or cancer in remission anticoagulation therapy that can't be stopped for surgery clotting disorders severe pulmonary disease

Kirwan JP, Axelrod CL, Kullman EL, Malin SK, Dantas WS, Pergola K, Del Rincon JP, Brethauer SA, Kashyap SR, Schauer PR. Foregut Exclusion Enhances Incretin and Insulin Secretion After Roux-en-Y Gastric Bypass in Adults With Type 2 Diabetes. J Clin Endocrinol Metab. 2021 Sep 27;106(10):e4192-e4201. doi: 10.1210/clinem/dgab255.