Bariatric surgery to treat type 2 diabetes: what is the recent evidence?

To critically discuss the strengths and shortcomings of recent progress achieved with bariatric surgery in patients with type 2 diabetes mellitus (T2DM), focussing on efficacy aspects (remission of diabetes and cardiovascular comorbidities). Despite an increasing armamentarium of pharmacotherapeutics to overcome several challenges, only 10% of T2DM patients achieve a composite goal of HbA1c, blood pressure and lipids. Bariatric surgery has emerged as a solution to these challenges in morbid obesity. Whether the same advantages can be translated into T2DM remains a matter of debate, certainly regarding safety, durability of diabetes recovery and long-term outcome.

Bariatric surgery in T2DM patients with a BMI of at least 35 kg/m(2) has been shown to result in a 56% excess body weight loss, resolution of hypertension in 62%, amelioration of dyslipidaemia in greater than 70% and diabetes remission in 57-95%, depending on the type of surgery and the definition of diabetes resolution. These impressive results, and the fact that diabetes recovery often occurs before prominent weight loss is evident, have urged bariatric surgeons to consider surgical procedures as a valuable approach for diabetes control and diabetes remission in patients with a BMI ranging between 30 and 35 kg/m(2).

Bariatric surgery is emerging as a valid option to treat T2DM, improving glycaemia and cardiovascular risk factors. However, there needs to be an agreed definition of resolution of diabetes in future studies and long-term efficacy is to be proven. For now, the challenge is to determine how to offer bariatric surgery in a responsible fashion.