The Recovery of Beta-Cell Function is Critical for Antidiabetic Outcomes of Gastric Bypass in Asian Subjects with Type 2 Diabetes and a Body Mass Index Below 30

Type 2 diabetes (T2D) in Asian populations is characterized by a lower body mass index (BMI) than in Caucasian cases. This pilot study investigated antidiabetic outcomes after a Roux-en-Y gastric bypass (RYGB) in Asian subjects with T2D and BMI < 30. Fifteen Koreans with poorly controlled T2D and BMI 23–30 underwent RYGB. Two years after RYGB, seven patients achieved HbA_1c < 6.5% without medication (target-achieved). The other cases also showed improved glycemic control. The insulin secretory response during an oral glucose tolerance test was significantly restored in the target-achieved group. Postoperative changes in insulin sensitivity and body weight did not differ between these groups. Beta-cell function improvement is an important determinant of the long-term antidiabetic outcomes of RYGB in Asian subjects with BMI < 30.