Glycemic Control after Sleeve Gastrectomy and Roux-En-Y Gastric Bypass in Obese Subjects with Type 2 Diabetes Mellitus

Roux-en-Y gastric bypass (LRYGB) has weight-independent effects on glycemia in obese type 2 diabetic patients, whereas sleeve gastrectomy (LSG) is less well characterized. This study aims to compare early weight-independent and later weight-dependent glycemic effects of LRYGB and LSG. Eighteen LRYGB and 15 LSG patients were included in the study. Glucose, insulin, GLP-1, and GIP levels were monitored during a modified 30 g oral glucose tolerance test before surgery and 2 days, 3 weeks, and 12 months after surgery. Patients self-monitored glucose levels 2 weeks before and after surgery. Postoperative fasting blood glucose decreased similarly in both groups (LRYGB vs. SG; baseline-8.1 +/- 0.6 vs. 8.2 +/- 0.4 mmol/l, 2 days-7.8 +/- 0.5 vs. 7.4 +/- 0.3 mmol/l, 3 weeks-6.6 +/- 0.4 vs. 6.6 +/- 0.3 mmol/l, respectively, P < 0.01 vs. baseline for both groups; 12 months-6.6 +/- 0.4 vs. 5.9 +/- 0.4, respectively, P < 0.05 for LRYGB and P < 0.001 for LSG vs. baseline, P = ns between the groups at all times). LSG, but not LRYGB, showed increased peak insulin levels 2 days postoperatively (mean +/- SEM; LSG + 58 +/- 14%, P < 0.01; LRYGB - 8 +/- 17%, P = ns). GLP-1 levels increased similarly at 2 days, but were higher in LRYGB at 3 weeks (AUC; 7525 +/- 1258 vs. 4779 +/- 712 pmol x min, respectively, P < 0.05). GIP levels did not differ. Body mass index (BMI) decreased more after LRYGB than LSG (- 10.1 +/- 0.9 vs. - 7.9 +/- 0.5 kg/m(2), respectively, P < 0.05). LRYGB and LSG show very similar effects on glycemic control, despite lower GLP-1 levels and inferior BMI decrease after LSG.