Mid-term results of bariatric surgery in morbidly obese Japanese patients with slow progressive autoimmune diabetes. 
Bariatric surgery is recognized as an effective treatment for type 2 diabetes mellitus, but data on its efficacy for type 1 diabetes mellitus, especially slowly progressive insulin-dependent diabetes mellitus, are limited.  We investigated five Japanese patients with slowly progressive insulin-dependent diabetes mellitus who underwent bariatric surgery at our center.  Five morbidly obese glutamic acid decarboxylase antibody-positive diabetic patients underwent two different types of bariatric surgery.  The mean titer of anti-glutamic acid decarboxylase antibody was 4.6 U/mL, and the mean preoperative bodyweight and BMI were 113 kg and 39.6 kg/m2 , respectively.  The mean hemoglobin A1c was 8.4%.  The mean fasting serum C-peptide was 5.0 ng/mL. Laparoscopic sleeve gastrectomy was performed in two patients, while laparoscopic sleeve gastrectomy with duodenojejunal bypass was performed in three patients.  At one year after surgery, the mean bodyweight and BMI significantly dropped, and the mean percentage of excess weight loss was 96.4%.  The mean hemoglobin A1c was 5.7%.  This favorable trend was maintained at mid-term.  Bariatric surgery for morbidly obese patients with anti-glutamic acid decarboxylase antibody-positive type 1 diabetes mellitus, especially slow progressive autoimmune diabetes, seemed effective in achieving mid-term glycemic control.  Longer follow-up with a larger number of patients, as well as validation with more advanced patients with slowly progressive insulin-dependent diabetes mellitus, will be needed.