A growing body of evidence indicates bariatric surgery is superior to medical and lifestyle therapies for the treatment of type 2 diabetes (T2D). Yet, randomized clinical trials of bariatric surgery have been limited in size, type of surgical procedure, and follow-up duration. As such, most clinicians do not recommend bariatric surgery for T2D patients with a body mass index (BMI) below 35.
The Alliance of Randomized Trials of Medicine vs Metabolic Surgery in Type 2 Diabetes (ARMMS-T2D) consortium pooled long-term observational results from four U.S. single-center randomized trials, which each compared bariatric surgery with medical/lifestyle treatment for T2D—the most extensive pooled analysis with the longest follow-up to date.
Donald C. Simonson, MD, ScD, a senior researcher in the Division of Endocrinology, Diabetes and Hypertension at Brigham and Women’s Hospital, local collaborators Ashley H. Vernon, MD, of the Department of Surgery, and Mary-Elizabeth Patti, MD, of the Joslin Diabetes Center, and colleagues recently conducted the ARMMS-T2D study with long-term follow-up of 7-12 years. They report that patients with T2D who underwent bariatric surgery experienced better long-term blood glucose control than those who received medical management plus lifestyle interventions, as well as higher rates of diabetes remission and less diabetes medication usage.
Their findings were published in JAMA and also shared in an NIH news release.
The four trials pooled in the ARMMS-T2D consortium were conducted from May 2007 to August 2013, and follow-up data was collected through July 2022. Each trial compared the outcomes of bariatric surgery vs. intensive lifestyle and medication therapy, involving oral and injectable diabetes medications, among patients with T2D and overweight or obesity. Participants were randomized to undergo medical/lifestyle management or one of three bariatric surgical procedures: Roux-en-Y gastric bypass, sleeve gastrectomy, or adjustable gastric banding.
At seven years, participants in the surgery group experienced better outcomes in weight loss, blood glucose control, and diabetes remission. In the surgery group:
- Participants experienced an average of 20% weight loss, compared to 8% in the medical/lifestyle group
- 54% of participants achieved an HbA1c less than 7%, compared to 27% of participants in the medical/lifestyle group
- 18.2% of participants achieved diabetes remission, compared to 6.2% in the medical/lifestyle group
- Diabetes medication use decreased from 98% to 61% among participants while remaining largely unchanged in the medical/lifestyle group
The differences between the two groups remained significant at 12 years. Notably, bariatric surgery had beneficial effects on HbA1c and weight loss among participants with a BMI between 27 and 34, indicating a benefit to surgery among patients who fall below the threshold of a BMI of 35.
“These results will help patients with type 2 diabetes and obesity make informed decisions about their best treatment options,” says Dr. Simonson.