Surgical approaches for the prevention and treatment of type 2 diabetes mellitus.

Lifestyle modifications and pharmacologic therapy have been the mainstays of treatment for patients with type 2 diabetes mellitus. Bariatric surgery, originally designed as a weight loss treatment, has been proven to ameliorate and even cure diabetes. The significant improvement in glycemic control found after bariatric surgery in patients with diabetes often precedes major weight loss. Therefore, a weight-independent mechanism has been thought to initiate this amelioration in glucose control. Reviews of the recent literature question the goal of bariatric surgery, not only to treat obesity through restriction and malabsorption, but also as a possible treatment for diabetes regardless of the degree of obesity. Procedures such as Roux-en-Y gastric bypass, adjustable gastric banding, and biliopancreatic diversion have proven to be extremely effective in controlling diabetes mellitus. Mechanisms explaining the effectiveness of weight reduction surgery include effects on incretins, ghrelin secretion, and insulin sensitivity. Some centers have been performing gastric bypass surgeries on patients with a lower body mass index than that recommended by current NIH guidelines. New considerations for recommending bypass surgery are warranted as the indications for antiobesity surgeries grow to encompass both the treatment and cure of diabetes.