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(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(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.