BackgroundBariatric surgery is an effective intervention for morbidly obese individuals, and it normalizes the level of glycemia in the majority of patients with type 2 diabetes mellitus (T2DM). ObjectivesThe primary aim of the study was to examine the efficacy of diverted sleeve gastrectomy with ileal transposition on weight loss and glycemic control in overweight, obese, and morbidly obese T2DM patients. The secondary aim was to examine the relationship between the effect of surgery and body mass index (BMI). SettingMetabolic surgery clinic. MethodsThis study was performed between October 2011 and August 2014, and mean duration of follow-up was 1 year. A total of 131 patients with T2DM were included. Ileal transposition with sleeve gastrectomy were performed in all patients. Each patient received a standard mixed meal tolerance test; plasma glucose, C-peptide, and insulin concentrations were measured before and 1 hour after the test. Postoperative alterations in BMI were noted. ResultsMean BMI decreased from 33.1±.5 to 23.5±.2 kg/m2 at 1 year, with the magnitude of weight loss correlating with baseline weight (P<.0001). There were marked decreases in fasting plasma glucose concentration and mean glycosylated hemoglobin levels at 1 year. Neither the decrease in fasting plasma glucose or glycosylated hemoglobin correlated with the decrease in weight. The homeostasis model assessment index decreased from 9.6±1.2 to 2.2±.2, P<.0001, and the Matsuda index for insulin sensitivity increased from 2.2±.2 to 7.8±.4, P<.0001. Despite the improvement in insulin sensitivity, surgery caused a 4-fold increase in insulin secretion (P<.01). ConclusionDiverted sleeve gastrectomy with ileal transposition is effective in glycemic control in patients with T2DM; however, this was not dependent on preoperative BMI values.