β-Cell Function and Sensitivity to Incretins Before and After Roux-en-Y Gastric Bypass in Individuals With Type 2 Diabetes.

Abstract

Roux-en-Y gastric bypass improves glycemic control in patients with type 2 diabetes, but the impact of the improved glycemic control on β-cell sensitivity to glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) is sparsely described. GLP-1 and GIP potentiated insulin secretion during clamped hyperglycemia before and after surgery, but, when related to the response to glucose alone, the relative potentiating effects of GIP (on first-phase insulin secretion) and GLP-1 (on first- and second-phase insulin secretion) were reduced postoperatively. The improvement in β-cell function after Roux-en-Y gastric bypass in patients with type 2 diabetes is not driven by improved β-cell sensitivity to incretins but rather other factors, including improved β-cell sensitivity to the changed glucose response and exaggerated postprandial GLP-1.