Normal Values of 24H Multichannel Intraluminal Impedance pH-Metry in a Greek Obese Population Based on Montreal Definition of Gerd

Background Although several studies reporting normal values of 24h multichannel intraluminal impedance pH (MIIpH) have been published, none of them has ever studied obese individuals. The purpose of this study is to determine overall frequency and duration of reflux episodes (acid and non-acid, supine-upright, post and preprandial) in obese asymptomatic volunteers. Methods Obese volunteers were enlisted during their preoperative evaluation for bariatric surgery. Volunteers had no gastroesophageal reflux disease (GERD) symptoms and no evidence of esophageal mucosal injury on endoscopy. Participants underwent a 24h MIIpH. Results In this prospective observational study, data of 22 obese individuals were analyzed. Mean age was 41.9 years and mean BMI was 47.1 kg/m 2 . Mean total reflux episodes was 55.6 and 95th percentile was 99.7. Mean percentage of total time with pH