Changes of blood glucose and gastrointestinal hormones 4 months after Roux‐en‐Y gastric bypass surgery in Chinese obese type 2 diabetes patients with lower body mass index

AIMS/INTRODUCTION The goal of this study was to evaluate the effect of Roux-en-Y gastric bypass (RYGB) on hyperglycemia and gastrointestinal hormones in Chinese obese type 2 diabetic patients with body mass index (BMI) between 28 and 35 kg/m(2). MATERIALS AND METHODS A total of eight obese type 2 diabetes patients with BMI 28-35 kg/m(2) who underwent RYGB and 10 obese normal glucose tolerance (NGT) patients with no surgery were identified. BMI and blood glucose on baseline, and 2-4 months postoperative, changes of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), peptide YY (PYY), and oxyntomodulin (OXM) were recorded. Efficacy of RYGB was defined by the percentage of excess weight loss (%EWL) and amelioration of type 2 diabetes. RESULTS The %EWL was 53.00 ± 26.25% in 2 month and 63.65 ± 33.71% in 4 month. Glycated hemoglobin changed from 7.2 ± 1.0% preoperative to 6.2 ± 0.9% in 2 month and 6.3 ± 1.2% in 4 month postoperative. The improvement rate of type 2 diabetes 4 months after RYGB was 83.3%. After surgery, area under the curve (AUC) GLP-1 120 increased with no significance. AUC PYY 120 changed from 10.37 ± 5.45 pmol/L/min preoperative to 22.19 ± 10.61 pmol/L/min in 2 month and 22.04 ± 7.73 pmol/L/min in 4 month postoperative. Postoperative AUC OXM 120 was also higher than that of the preoperative level. AUC GIP 120 decreased from 13.06 ± 8.45 pg/mL/min preoperative to 8.71 ± 3.28 pg/ml/min in 2 month and 6.88 ± 2.33 pg/mL/min in 4 month postoperative. CONCLUSIONS Roux-en-Y gastric bypass has a beneficial effect on weight loss and glucose metabolism in obese type 2 diabetes patients with lower BMI. Postoperative concentrations of GLP-1, PYY and OXM increased, whereas GIP decreased.