**8. Indications for bariatric surgery in adults with type 2 diabetes mellitus**

Bariatric surgery is clearly indicated in type 2 diabetes mellitus patients with BMI >35kg/m2 (evidence level A) especially if diabetes or associated comorbidities are difficult to control with lifestyle and pharmacological therapy. In these patients surgery can contribute to beta cell function improvement and diabetes remission. For patients with type 2 diabetes mellitus and BMI ranged between 30 and 35 kg/m2 surgery may be considered on an individual basis (evidence level A, B, C and D). [77] In patients with type 2 diabetes and BMI >30 kg/m2 and <35 kg/m2 , bariatric surgery may be considered if HbA1c >7.5% despite fully optimized conventional therapy, especially weight is increasing, or other weight responsive co-morbid‐ ities not achieving targets on conventional therapies (blood pressure, dyslipidaemia, and obstructive sleep apnea). [60] There are insufficient data to generally recommend surgery in patients with BMI under 35 kg/m2 outside of a research protocol. [76] Table 1 summarized indications of bariatric surgery in type 2 diabetes mellitus according different international organizations.
