Esophageal Function Assessment Using Endoscopic Functional Luminal Imaging Probe (ENDOFLIP) in Patients With Different Obesity Classes

Introduction: Patients with obesity have been found to have a higher prevalence of esophageal motor disorders compared to the general population, with abnormal lower esophageal sphincter (LES) function and altered peristalsis on manometry. Patients with class 3 obesity can experience minimal symptoms despite abnormal manometry suggesting abnormal visceral sensation. Endoscopic functional luminal imaging probe (EndoFLIP) assesses luminal distensibility and peristalsis during endoscopy. This study aims to evaluate esophageal characteristics using EndoFLIP in patients with obesity and esophageal symptoms and determine clinical differences between obesity classes. Methods: We conducted retrospective chart review of patients with obesity and esophageal symptoms who had undergone EndoFLIP testing at a single tertiary care center between 2020-2022. Data was collected on patient demographics, symptoms, medical history, and EndoFLIP measurements. Statistical analysis was performed using Fisher exact testing. Results: 33 patients with a BMI ≥30 were included (81% women, mean age 50.2 years, mean BMI 39.4). 9 (27%) had class 3 obesity, 9 (27%) class 2 obesity and 15 (45%) class 1 obesity. Most common symptoms were dysphagia (72%), heartburn (48%), reflux (48%), and regurgitation (42%). On EndoFLIP, 8 (24%) had reduced esophagogastric junction distensibility index (EGJ-DI), of which 2 (13%) were classified as obesity class 1, 4 (44%) obesity class 2 and 2 (22%) obesity class 3 (Table). 17 (52%) had normal repetitive antegrade contractions (RACs), 7 (21%) diminished/disordered contractile response (DDCRs) and 9 (27%) absent contractility. Abnormal contractility patterns were seen in 7 (47%) obesity class 1, 4 (44%) obesity class 2 and 5 (56%) obesity class 3. There were no significant differences between obesity classes with regards to medication use, co-morbidities, symptoms, endoscopy and EndoFLIP findings. Conclusion: In this cohort, symptomatic patients in different obesity classes did not have significantly different LES function or peristalsis on EndoFLIP. EGJ distensibility was reduced in a quarter of the study population and seen more frequently in patients with class 2 obesity. Nearly half of the patients had abnormal peristalsis with DDCRs and absent contractility, with similar representation between obesity classes. Prospective controlled studies with EndoFLIP comparing symptomatic and asymptomatic patients in different obesity classes are needed to validate these findings. Table 1. - Comparison of patient characteristics and EndoFLIP findings by obesity class Class 1 Obesity BMI 30-35 (N=15) Class 2 Obesity BMI 35-40 (N=9) Class 3 Obesity BMI >40 (N=9) p-value MEDICATIONS N (%) PPI 8 (53) 6(67) 5 (56) 0.67 H2 blocker 5 (33) 1 (11) 2 (22) Opiods 2 (13) 0 2 (22) Benzodiazepines 0 1 (11) 0 SYMPTOMS N (%) Reflux 6 (40) 6 (67) 4 (44) 0.57 Dysphagia 12 (80) 7 (78) 5 (56) Heartburn 7 (47) 4 (44) 5 (56) Regurgitation 3 (20) 4 (44) 7 (78) Belching/Nausea 2 (13) 1 (11) 1 (11) Epigastric abdominal pain 4 (27) 2 (22) 2 (22) Vomiting 1 (7) 2 (22) 1 (11) EGD FINDINGS N (%) Esophagitis 4 (27) 2 (22) 3 (33) 0.78 Gastritis 8 (53) 4 (44) 5 (56) Fluid in esophagus 1 (7) 2 (22) 3 (33) ENDOFLIP FINDINGS EGJ-distensibility index N (%) [mean] Normal 13 (87) [5.4] 5 (56) [4.65] 7 (78) [4.98] 0.26 Reduced 2 (13) [2.27] 4 (44) [0.91] 2 (22) [2.82] Contractility pattern N (%) RACs 8 (53) 5 (56) 4 (44) 1 DDCRs 3 (20) 2 (22) 2 (22) Absent contractility 4 (27) 2 (22) 3 (33) BMI = Body Mass Index; PPI = Proton pump inhibitor; H2 blocker = histamine 2 blocker (eg. famotidine); EGD = Esophagogastroduodenoscopy; EGJ = Esophagogastric Junction; RACs = Repetitive Antegrade Contractions; DDCRs = Diminished or Disordered Contractile Responses