Timing of bariatric surgery in people with obesity and diabetes

The use of bariatric surgery in the clinical management of type 2 diabetes in severely obese subjects has been included in the clinical practice recommendations released by the most influential diabetologic associations. However, the timing during the diabetic course in which this use may have the better benefit/risk ratio remains debated. Is it better to use surgery very early in the course of the disease in order to anticipate clinical deterioration, or we should favour a delayed approach in which we reserve the more risky surgery only to patients not adequately controlled with the maximal pharmacologic strategy? In this paper, past and recent evidences about the role of bariatric surgery in the different stages of the clinical course of type 2 diabetes have been revised, starting from pre-diabetes and ending to long-standing diabetic state with established or end-stage macro- and micro-vascular complications. Available evidences strongly advocate in favor of the application of bariatric surgery in the early phase of this course, possibly in the pre-diabetic or in very early diabetic stages. To reserve surgery to more advanced and complicated stages of the disease seems to confer less benefits for the clinical course of diabetes and exposes these more frail patients to the possible side effects of a rapid weight loss.