Gastrointestinal Physiological Changes and Their Relationship to Weight Loss Following the POSE Procedure

Background: Primary Obesity Surgery Endolumenal (POSE) is a novel bariatric endoscopic procedure that has been shown to reduce weight safely through 12 months. The study investigated potential mechanisms of weight loss following POSE.

Methods: Patients with class I-II obesity received transmural plications in the gastric fundus and distal gastric body. Patients were evaluated at baseline and at 2- and 6-month follow-up with gastric-emptying (GE) scintigraphy, a validated test of intake capacity (kcal) and plasma glucose homeostasis hormones/gastrointestinal peptides. Weight was recorded through 15 months. Mean data and 95% CIs are reported. Regression modeling assessed variables that influenced total weight loss (%TWL) and excess weight loss (%EWL).

Results: POSE was performed on 18 patients (14 F/4 M); mean age 39 years (34-44), body mass index (BMI, kg/m(2)) 36 (95% CI, 35; 37). At 15 months (n = 15), mean TWL was 19.1 ± 6.6% (15.5; 22.8) and EWL was 63.7 ± 25.1% (49.8; 77.6). At 2 and 6 months (n = 18), intake capacity decreased significantly from 901 (685; 1117) to 473 (345; 600) and 574 kcal (418; 730), respectively (p < 0.001). At 2 months, GE was delayed but returned to baseline levels at 6 months (n = 18). Glucose/insulin ratio improved (p < 0.05). Postprandial decrease in ghrelin was enhanced (p = 0.03) as well as postprandial increase in PYY (p = 0.001). The best model for EWL prediction 15 months after POSE (R (2): 66%, p = 0.006) included pre-POSE BMI, post-POSE GE, and postprandial PYY increase.

Conclusions: The POSE procedure was followed by significant sustained weight loss and improved glucose homeostasis and satiation peptide responses. Weight loss following POSE may be mediated through changes in gastrointestinal neuro-endocrine physiology.