Background: Bariatric surgery has been effective in weight loss and comorbidity resolution, especially diabetes. Laparoscopic Roux-En-Y Gastric bypass (LRYGB) is still a standard procedure and thought to play a major role in glucose homeostasis and diabetic control. Laparoscopic sleeve gastrectomy (LSG) is gaining popularity as an optional procedure in morbid obese patient with comparable outcome to gastric bypass. However, there is lack of data in Thailand.

Objective: The primary outcome was to compare the effect on diabetic control after LSG and LRYGB surgery. The secondary outcome was to evaluate the excess weight loss (EWL).

Materials and Methods: The present study was a prospective, randomized clinical trial in morbid obese patient with type 2 diabetes (T2DM). The study examined Thai patients with age between 15 and 60 years, BMI 32.5 to 60, history of T2DM of less than 10 years, and preoperative plasma HbA1c level of more than 7%. Follow-up at six months and two years after surgery to evaluate plasma HbA1c level, percentage of EWL, and remission rate of diabetes after surgery.

Results: One hundred four patients were randomized into 48 patients in LSG group and 56 patients in LRYGB group. There was no difference in baseline BMI and plasma HbA1c level between the two groups. Average EWL at six months were 42.76±3.44% in LSG group and 55.07±10.07% in LRYGB group (p=0.006), and EWL at two years were 58.31±7.78% in LSG group and 70.12±12.12% in LRYGB group (p<0.001). Reduction in mean plasma HbA1c level change (preop to postop) at six months after surgery were 1.87±0.98 in LSG group and 2.72±1.2 in LRYGB group (p=0.619). Reduction in mean HbA1c level change (preop to postop) at two years after surgery were 2.43±1.4 in LSG group and 3.1±1.76 in LRYGB group (p=0.737). Remission rate of T2DM at six months were 58.30% in LSG group and 62.07% in LRYGB group (p=0.481). Remission rate of T2DM at two years were 66.67% in LSG and 70.64% in LRYGB group (p=0.454). Both groups showed a decrease in antihyperglycemic drugs used after surgery but there was no statistically significant difference.

Conclusion: LRYGB is statistically significant more effective than LSG in EWL. However, there is no difference in the effectiveness of diabetic control between the two procedures in both short-term and long-term results.