**7. Actual guidelines for surgical treatment in diabetic patients**

characterized by continuous decrease of beta cell function. Absence of insulin treatment was a predictive factor for remission of diabetes after bariatric surgery. [68, 71] The insulin use was associated with lower remission rates compared with oral medication (13.5 versus

**d. Weight loss**. The amount of weight loss seems to be of major importance in the improve‐ ment of glucose control after laparoscopic adjustable gastric banding. [52] Also percentage weight loss at 1 year over 25% independently influenced remission of diabetes after gastric bypass. [69] But no correlation between normalization of fasting glucose levels and weight loss after gastric bypass and biliopancreatic diversion was observed in another study. [54] Weight changes after these former surgical procedures were not significant predictors of diabetes remission at 2 years or of normalization of glycated hemoglobin. [54] But in the Diabetes Surgery Study weight loss explains most of the benefit on glycemic control of

were predictive factors for diabetes remission whatever the procedures. [71]

**e. Initial level of C peptide:** Fasting C-peptide concentration is correlated with beta cell mass and insulin secretion. Very low C-peptide levels could be useful in identifying type 1 diabetes and latent autoimmune diabetes in adults that could have as comorbidity obesity. C-peptide levels are increased as response to insulin resistance in obese type 2 diabetes subjects and are correlated with BMI but decreased with duration of diabetes. [69] A high level of C-peptide before metabolic surgery increased the chance of a good outcome. The cut-off value of C-peptide ≥2.9ng/ml at baseline predicts the remission of diabetes after gastric bypass. [69] Also in another study the diabetes remission rates strongly correlate with the level of C-peptide: 55.3% for those with preoperative C-peptide <3ng/ml, 82% for C-peptide 3-6ng/ml, and 90.3% for C-peptide > 6ng/ml. [73] Another study showed that 90% of type 2 diabetes patients with preoperative fasting C-peptide levels over 1 nmol/l had mean A1c <6.5% after Roux-en-Y gastric bypass and 74% had complete resolution of diabetes. But none of the patients with fasting C-peptide level less than 1 nmol/l before surgery experienced diabetes remission. The authors of this study recommend fasting C-peptide levels to be measured in order to a better prediction of

**f. Type of surgical procedures** Preoperative data of patients could be of greater importance in the resolution of diabetes than the choice of bariatric surgery procedures. There are several studies that analysed the efficiency of different types of surgical procedures, reporting remission rates of 7-70% for gastric banding, 38-98% for gastric by-pass, 33-85% for sleeve gastrectomy and 52-100% for biliopancreatic diversion. [75] Weight loss and diabetes resolution were greatest for patients undergoing biliopancreatic diversion/ duodenal switch, followed by gastric bypass, and least for banding procedures. [49] The combination of these factors has an increased power in prediction of the outcomes. If a score of 1 is assigned to duration of diabetes <4years, percentage weight loss at 1 year >25%, and C-peptide ≥2.9ng/ml at baseline, a cumulative score of 2 or 3 was associated with a remission rate of 92%, and a score of 0 or 1 was associated with a remission rate of 27%. [69]

and a one year BMI under 35 kg/m2

gastric bypass. [55] A baseline BMI under 50 kg/m2

diabetes remission after surgery. [74]

53.8%). [72]

208 Treatment of Type 2 Diabetes

Obesity and type 2 diabetes mellitus are chronic, multifactorial and complex disorders with serious outcomes on health and requires multidisciplinary approach in order to improve prognostic.

Several international society have launched their guidelines, position statement and recom‐ mendations on type 2 diabetes mellitus and metabolic surgery based on growing evidences form observational, randomized controlled studies and metaanalysis. [60, 76-79] These guidelines and position statement are needed because the global prevalence of type 2 diabetes is rising dramatically as a consequence of obesity epidemic and environmental changes including high calorie food abundance and lack of physical activity. Type 2 diabetes and obesity are associated with premature morbidity and mortality and are major public health threats of the 21st century. There is increasing evidence that prognostic of patients with type 2 diabetes mellitus and obesity is dramatically improved by bariatric surgery that produces important weight loss, substantially decreases of glycated hemoglobin, improvement of lipid profile and reduces the cardiovascular risk and it even can produces remission of diabetes. [60] Bariatric surgery for severe obesity associated with diabetes mellitus is cost-effective. [60]
