Effects of transoral gastroplasty on glucose homeostasis in obese subjects

Context and Objective: Transoral gastroplasty (TOGA) is a safe and less invasive procedure than traditional bariatric surgery. We studied the effects of TOGA on the risk of progression from prediabetes to overt type 2 diabetes mellitus (T2DM) or on regression from diabetes or prediabetes to a lower risk category. Design and Setting: Prospective, observational study (October 2008 to October 2010) performed at Catholic University, Rome, Italy. Fifty consecutive subjects 18-60 years old, 35 >= body mass index < 55 kg/m, were enrolled. Glucose tolerance, insulin sensitivity, and secretion were studied at baseline and 1 week and 1, 6, and 12 months after TOGA. Plasma glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), and ghrelin levels were measured. Results: Forty-three patients (86%) completed the 1-year postoperative follow-up. Patients lost 16.90% of baseline weight (P level × factor time<0.001). Body mass index decreased from 42.24 ± 3.43 to 34.65 ± 4.58 kg/m (P ± .001). Twenty-three patients (53.5%) were diagnosed as normal glucose tolerance (NGT) before treatment, 2 (4.6%) were impaired fasting glucose (IFG), 12 (27.9%) were impaired glucose tolerance (IGT), 1 (2.3%) had both IFG and IGT, and 5 (11.6%) had T2DM. At 1-year posttreatment, the percentages changed to 86.0% NGT, 2.3% IFG, 11.6% IGT,0%IFG plus IGT, and 0% T2DM, respectively. Peripheral insulin resistance and homeostasis model of assessment-insulin resistance improved significantly. Fasting glucose-dependent insulinotropic peptide and ghrelin decreased from 316.9 ± 143.1 to 156.2 ± 68.2 pg/mL (P < .001) and from 630.6 ± 52.1 to 456.7 ± 73.1 pg/mL (P < .001), respectively, whereas GLP-1 increased from 16.2 ± 4.9 to 23.7 ± 9.5 pg/mL (P < .001). Conclusions: TOGA induced glucose disposal improvement with regression of diabetes to NGT or IGT and regression of IGT and IFG to NGT in half of the cases. Regressors showed a much larger increase of GLP-1 levels than progressors. Copyright © 2013 by The Endocrine Society.