Which weight loss operation is superior for patients with type 2 diabetes? The authors of a recent study conducted a randomized trial of moderately obese patients (BMI < 35) with troublesome, difficult diabetes. Patients were followed for 1 year. The main endpoint was control of diabetes and secondary outcomes were weight loss and remission of metabolic syndrome. Nearly all patients (93%) in the gastric bypass group had a remission of diabetes, compared with less than half of patients (47%) with sleeve gastrectomy. Weight loss was also more pronounced after gastric bypass.
What is interesting about this study is that it again demonstrates that control of diabetes induced by the surgery occurred more rapidly than weight loss induced by the surgery. This suggests that the improvement is related to a change in insulin resistance caused by the operation, not just weight loss alone. The exact mechanism by which obesity surgery ameliorates diabetes is unclear, but bypassing the duodenum seems to be important.
Lee WJ, Chong K, Ser KH, et al Arch Surg. 2011;146:143-148