• S R Kashyap, S Daud, K R Kelly, A Gastaldelli, H Win, S Brethauer, J P Kirwan, and P R Schauer.
• Endocrinology and Metabolism Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA. kashyas@ccf.org
• Int J Obes (Lond). 2010 Mar 1;34(3):462-71.

ContextHyperglycemia resolves quickly after bariatric surgery, but the underlying mechanism and the most effective type of surgery remains unclear.ObjectiveTo examine glucose metabolism and beta-cell function in patients with type 2 diabetes mellitus (T2DM) after two types of bariatric intervention; Roux-en-Y gastric bypass (RYGB) and gastric restrictive (GR) surgery.DesignProspective, nonrandomized, repeated-measures, 4-week, longitudinal clinical trial.PatientsIn all, 16 T2DM patients (9 males and 7 females, 52+/-14 years, 47+/-9 kg m(-2), HbA1c 7.2+/-1.1%) undergoing either RYGB (N=9) or GR (N=7) surgery.Outcome MeasuresGlucose, insulin secretion, insulin sensitivity at baseline, and 1 and 4 weeks post-surgery, using hyperglycemic clamps and C-peptide modeling kinetics; glucose, insulin secretion and gut-peptide responses to mixed meal tolerance test (MMTT) at baseline and 4 weeks post-surgery.ResultsAt 1 week post-surgery, both groups experienced a similar weight loss and reduction in fasting glucose (P<0.01). However, insulin sensitivity increased only after RYGB, (P<0.05). At 4 weeks post-surgery, weight loss remained similar for both groups, but fasting glucose was normalized only after RYGB (95+/-3 mg 100 ml(-1)). Insulin sensitivity improved after RYGB (P<0.01) and did not change with GR, whereas the disposition index remained unchanged after RYGB and increased 30% after GR (P=0.10). The MMTT elicited a robust increase in insulin secretion, glucagon-like peptide-1 (GLP-1) levels and beta-cell sensitivity to glucose only after RYGB (P<0.05).ConclusionRYGB provides a more rapid improvement in glucose regulation compared with GR. This improvement is accompanied by enhanced insulin sensitivity and beta-cell responsiveness to glucose, in part because of an incretin effect.

31 keywords...

hide…