Prevalence and predictors of weight recurrence following bariatric surgery: A longitudinal prospective cohort study from Tehran Obesity Treatment Study (TOTS)

Background: Considering the lack of a standardized definition for weight recurrence (WR), the prevalence and predictors of WR remain inconsistent. Methods: The prospective study was conducted on 1939 individuals who underwent bariatric surgery;66.8% underwent sleeve gastrectomy (SG), 33.2%, underwent gastric bypass (GB)[of them 87% one-anastomosis gastric bypass (OAGB), and 13% Rue and Y gastric bypass (RYGB)]. During a follow-up of 72 months, the prevalence of WR ranged from 13.5% to 35.5% according to five different definitions. The generalized estimated equation method was used to assess weight changes, excess weight loss (EWL%), and body composition (fat mass (FM), fat-free mass (FFM)and FFM loss/weight loss% (FFML/WL%)) by a bioelectrical impedance analyzer. Stepwise logistic regression models were applied to determine the independent predictors of WR. Results: Among 1939 participants followed up for 72 months, WR definitions were applied to 650 patients (75.4% females) with an average BMI of 44.3 +/- 5.4 kg/m2,491 (75.5%) and 159 (24.5%) of whom underwent SG and GB, respectively. WR group had relatively higher weights and FM and lower EWL%. A WR turning point was observed at 24 months post-surgery (Ptime before & after 24 months<0.001). The most significant risk factors for WR included SG (in all WR definitions), a younger age (in four out of five definitions), and a higher baseline BMI (in three out of five definitions). Conclusion: The prevalence and predictors of WR varied greatly depending on the definition applied. The prominent risk factors of WR included SG, younger age, and a higher baseline BMI.