Different types of weight loss surgeries have exhibited varied efficacies in controlling type 2 diabetes (T2D) in individuals with severe obesity and T2D. Data have shown that Roux-en-Y gastric bypass (RYGB) is more successful for T2D remission and leads to faster metabolic improvements than laparoscopic adjustable gastric banding (LAGB). However, many researchers think that the observed superior effects of RYGB is confounded by greater and faster weight loss after RYGB than after LAGB.
Researchers at the Department of Medicine at Columbia University College of Physicians and Surgeons (New York, NY) decided to study the post bariatric surgical effects on glucose metabolism independent of the amount of weight lost. They enrolled 61 eligible patients at Mount Sinai St. Luke’s Hospital who were scheduled for either RYGB or LAGB, and conducted multiple metabolic tests prior to surgery and after patients reached 10% and 20% weight loss and/or at 1 year after each type of surgery.
The researchers found that RYGB led to greater release of glucagon-like peptide 1 (GLP-1; a hormone that stimulates insulin secretion in response to a meal) compared with LAGB at any level of weight loss. Comparing patients at 10% weight loss, RYGB decreased glucose levels more than LAGB. However, after 20% weight loss from either type of surgery, the improvement in glucose metabolism, the rate of T2D remission, the use of T2D medications, insulin sensitivity, and β-cell function were similar.
The study results were published in the journal Diabetes Care (Jan 2017).
Why is this Clinically Relevant?
- Weight loss, not surgery type, is a predictor of insulin sensitivity in bariatric patients
- Although RYGB leads to faster weight loss, greater improvements in overall glucose metabolism, and more GLP-1 response, the advantages of RYGB to LAGB is attenuated after larger weight losses
- The amount of weight loss post-surgery—not the type of bariatric surgery utilized—is the key factor for long-term glucose control and T2D remission
- Because many bariatric patients experience weight regain after initial weight loss, it is important for clinicians to work with patients to develop a long-term strategy in weight loss maintenance
 Holter, M.M., et al., Glucose Metabolism After Gastric Banding and Gastric Bypass in Individuals With Type 2 Diabetes: Weight Loss Effect. Diabetes Care, 2017. 40(1): p. 7-15.