Initially, 4 teams of investigators conducted randomized controlled trials (RCT) at their own site to evaluate the effectiveness of bariatric surgery compared to medical/lifestyle management of type 2 diabetes. Each study followed subjects for a duration of about 1 - 3 years. Following this, a consortium was created to pool data and continue to follow study participants. This early collaboration of the 4 groups of investigators was supported by Industry sponsors (Ethicon, Inc and Medtronic-MITG). Now, the investigators have successfully received a grant from the NIH, as the sole supporter of continued observational follow-up of study participants.

The continuing aim of this study is to combine data from the 4 studies and follow the original randomized subjects for an additional 5 years of follow-up. The purpose of the study is to determine the longer term durability and effectiveness of bariatric surgery compared to medical/lifestyle intervention on the treatment of type 2 diabetes.

The four investigative groups initiated their individual RCT's at their respective sites to evaluate the effectiveness of bariatric surgery compared to multidisciplinary medical and lifestyle management of diabetes and body weight. The original trials were each designed to assess feasibility over a relatively short duration of follow-up (1-3 years). Individually, each trial lacked the sample size and duration of follow-up to meaningfully inform clinical decision making. Together, with the funding provided by the NIH for longer follow-up, the Consortium trial can provide a unique national resource to address timely and unanswered clinical questions related to the durability of these alternative management approaches in patients with T2D and obesity. Together, participants from these studies represent the largest cohort with diabetes (one third having a BMI <35 kg/m2) ever to undergo randomized assignment to bariatric surgical procedure vs. medical/lifestyle intervention.

Inclusion Criteria:

• Original inclusion criteria for participation in the RCTs at all sites included:

  • Candidate for general anesthesia or unsupervised exercise.
  • Age ≥20 and ≤65 years.
  • Body mass index >27 and ≤45 kg/m2.
  • Diagnosis of type 2 diabetes confirmed by either requiring diabetes medication and/or having elevated glycemia based on HbA1c, fasting plasma glucose, and/or oral glucose tolerance test (OGTT) results, according to American Diabetes Association criteria.
  • Ability and willingness to participate in the study and agree to any of the research arms.
  • Able to understand the options and to comply with the requirements of each program.
  • Negative urine pregnancy test at screening and baseline visits (prior to surgery) for women of childbearing potential (i.e., biologically capable of becoming pregnant).

Exclusion Criteria:

• Subjects who were randomized in one of the four RCTs but never initiated intervention / did not receive randomized treatment
• Refusal to sign informed consent

Subjects who were previously enrolled in a Randomized Control Trial (RCT) at one of the four participating sites who initiated one of the intervention procedures - bariatric surgery or medical/lifestyle therapy.