The Effect of Roux-en-Y Gastric Bypass on Hormones Involved in Body Weight Regulation and Glucose Metabolism
Abstracts
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Purpose: To evaluate the effect of Roux-en-Y gastric bypass on hormones involved in body weight regulation and glucose metabolism. Methods: Ten patients (9 females and 1 male) with a mean pre-operative BMI of 46.2 kg/m2 (40-53 kg/m2) underwent laparoscopic Roux-en-Y gastric bypass. Six patients had type 2 diabetes treated by oral hypoglycemic agents. Preoperatively and three weeks following surgery, the patients were tested for fasting glucose, insulin, glucagon, insulin-like growth factor 1 (IGF-1), leptin, gastric inhibitory polypeptide (GIP), glucagon-like peptide-1 (GLP-1), cholecystokinin (CCK), adrenocorticotropic hormone (ACTH), corticosterone, and neuropeptide Y (NPY). Results: Mean postoperative BMI was 43.2 kg/m2 (p=ns). There was a significant decrease in blood glucose (p=0.005), insulin (p=0.02), IGF-1 (p<0.05) and leptin (p=0.001). Mean ACTH increased from 15.38?8.3 pg/ml to 20.99?5.0 pg/ml (p=0.01). Although not significantly, the other hormones were either increased (enteroglucagon, corticosterone, GLP-1 and CCK) or decreased (GIP and NPY). All the six patients with type 2 diabetes had normal glucose and insulin levels and were out of medications within three weeks of surgery. Preoperatively, GIP levels were higher in diabetic patients (p<0.05). After surgery, GIP decreased to normal (p<0.01) in diabetics while was not changed in non-diabetics. Conclusions: Gastric bypass determines rapid and significant hormonal changes. Normalization of GIP levels parallels resolution of type 2 diabetes after surgery. These results support the hypothesis of a hormonal effect as the possible mechanism of action of gastric bypass. |
