Metabolic Effects of Bariatric Surgery in Patients With Moderate Obesity and Type 2 Diabetes Analysis of a randomized control trial comparing surgery with intensive medical treatment

OBJECTIVETo evaluate the effects of two bariatric procedures versus intensive medical therapy (IMT) on -cell function and body composition.RESEARCH DESIGN AND METHODSThis was a prospective, randomized, controlled trial of 60 subjects with uncontrolled type 2 diabetes (HbA(1c) 9.7 1%) and moderate obesity (BMI 36 2 kg/m(2)) randomized to IMT alone, IMT plus Roux-en-Y gastric bypass, or IMT plus sleeve gastrectomy. Assessment of -cell function (mixed-meal tolerance testing) and body composition was performed at baseline and 12 and 24 months.RESULTSGlycemic control improved in all three groups at 24 months (N = 54), with a mean HbA(1c) of 6.7 +/- 1.2% for gastric bypass, 7.1 +/- 0.8% for sleeve gastrectomy, and 8.4 +/- 2.3% for IMT (P < 0.05 for each surgical group versus IMT). Reduction in body fat was similar for both surgery groups, with greater absolute reduction in truncal fat in gastric bypass versus sleeve gastrectomy (-16 vs. -10%; P = 0.04). Insulin sensitivity increased significantly from baseline in gastric bypass (2.7-fold; P = 0.004) and did not change in sleeve gastrectomy or IMT. -Cell function (oral disposition index) increased 5.8-fold in gastric bypass from baseline, was markedly greater than IMT (P = 0.001), and was not different between sleeve gastrectomy versus IMT (P = 0.30). At 24 months, -cell function inversely correlated with truncal fat and prandial free fatty acid levels.CONCLUSIONSBariatric surgery provides durable glycemic control compared with intensive medical therapy at 2 years. Despite similar weight loss as sleeve gastrectomy, gastric bypass uniquely restores pancreatic -cell function and reduces truncal fat, thus reversing the core defects in diabetes.