High Prevalence of Positive Genetic Obesity Variants in Postoperative Bariatric Surgery Patients with Weight Regain Presenting for Medical Obesity Intervention

Introduction Genetic obesity susceptibility in postoperative bariatric surgery weight regain (PBSWR) remains largely unexplored. Methods A retrospective case series of adult ( N = 27) PBSWR patients who had undergone genetic obesity testing was conducted between Sept. 2020 and March 2022. Primary outcome: frequency of genetic variants in patients experiencing weight regain following bariatric surgery. Secondary outcomes: prevalence of obesity-related comorbidities, nadir BMI achieved post-bariatric surgery, and percent total body weight loss (%TBWL) achieved with obesity pharmacotherapies. Results Heterozygous mutations were identified in 22 (81%) patients, with the most prevalent mutations occurring in CEP290, RPGR1P1L, and LEPR genes (3 patients each). Median age was 56 years (interquartile range (IQR) 46.8–65.5), 88% female. Types of surgery were 67% RYGB, 19% SG, 4% gastric band, and 13% revisions. Median nadir BMI postoperatively was 34.0 kg/m 2 (IQR 29.0–38.5). A high prevalence of metabolic derangements was noted; patients presented median 80 months (IQR 39–168.5) postoperative for medical weight management with 40% weight regain. BMI at initiation of anti-obesity medication (AOMs) was 41.7 kg/m 2 (36.8–44.4). All received AOM and required at least 3 AOMs for weight regain. Semaglutide ( N = 21), topiramate ( N = 14), and metformin ( N = 12) were most prescribed. Median %TBWL for the cohort at the first, second, and third visit was 1.7, 5.0, and 6.5 respectively. Fourteen (52%) achieved 5%TBWL, 10 (37%) achieved 10%TBWL, and 4 (15%) achieved 15%TBWL with combination AOMs and supervised medical intervention. Conclusion An unusually high prevalence of genetic obesity variants in PBSWR was found, warranting further research. Graphical Abstract