β-Cell Function Improvements in Grade I/II Obese Subjects With Type 2 Diabetes 1 Month After Biliopancreatic Diversion Results from modeling analyses of oral glucose tolerance tests and hyperglycemic clamp studies

OBJECTIVE To investigate the effect of biliopancreatic diversion (BPD) surgery on β-cell function in grade I and II obese patients with type 2 diabetes using oral and intravenous glucose loads. RESEARCH DESIGN AND METHODS Sixty-eight women were divided into the following three groups: 19 lean-control (23.0 ± 2.2 kg/m 2 ) and 18 obese-control (35.0 ± 4.8 kg/m 2 ) subjects with normal glucose tolerance, and 31 obese patients with type 2 diabetes (36.3 ± 3.7 kg/m 2 ). Of the 31 diabetic women, 64% underwent BPD ( n = 20, BMI: 36.5 ± 3.7 kg/m 2 ) and were reassessed 1 month after surgery. Oral glucose tolerance tests and hyperglycemic clamps were performed. Mathematical modeling was used to analyze basal and stimulated β-cell function, insulin sensitivity (IS), hepatic extraction (HE) of insulin, and delay time of β-cell response to a specific plasma glucose concentration. RESULTS After BPD, restoration of the basal disposition index ( P P oral ) and intravenous clamp glucose stimulation (IS clamp ) was completely normalized ( P oral and IS clamp increased approximately 5.0-fold and 3.5-fold, respectively ( P P P CONCLUSIONS β-Cell function, IS, and HE of insulin improved after BPD, which improved glycemic control.