https://diabetes.acponline.org/archives/2013/11/08/7.htm

Review: Bariatric surgery improves weight and glycemia in nonmorbidly obese adults with diabetes

A review of 3 randomized controlled trials found that surgical treatment increased weight loss and improved diabetes-related outcomes more than nonsurgical treatment in moderately obese patients.


A review of 3 randomized controlled trials, including 290 moderately obese patients with diabetes or glucose intolerance, found that surgical treatment increased weight loss and improved diabetes-related outcomes at 24 months more than nonsurgical treatment in patients with body mass indexes of 30 to 35 kg/m2.

The study was published in the June 5 Journal of the American Medical Association. A summary of the study was published in the June ACP DiabetesMonthly. The following commentary by Raj Padwal, MD, MSc, was published in the ACP Journal Club section of the Oct. 15 Annals of Internal Medicine.

Bariatric surgery is the most effective treatment currently available for reducing weight and improving obesity-related comorbid conditions. Diversionary procedures (including gastric bypass and biliopancreatic diversion) are particularly effective for type 2 diabetes because they appear to improve glycemic control independent of weight loss. Enhanced secretion of enteric hormones, including incretins, may mediate these additional benefits. Glycemic control improves to the greatest extent in diet-controlled diabetes of short duration.

Widely used eligibility criteria for bariatric surgery endorse surgery for medically refractory patients with BMI 35.0 to 39.9 kg/m2 and a major obesity-related comorbidity or BMI ≥ 40 kg/m2. These arbitrarily set cutpoints have been criticized for being restrictive and lacking evidence. Surgery in patients with diabetes and BMI between 30 to 35 kg/m2 seems to be justified given the results of the review by Maggard-Gibbons and colleagues.

The decision to perform surgery in any patient must balance known risks and benefits and limitations of current evidence. Trials were relatively short and not designed to assess microvascular complications, macrovascular disease, or long-term mortality. Effects of long-term nutrient deficiencies require further study. Durability of diabetes remission must be clarified; recent studies suggest that only 65% of patients remain in remission after 5 years. Future studies are required to address these knowledge gaps and clarify the risk–benefit profile of surgery in patients with type 2 diabetes.