Demographic, clinical, and behavioral determinants of 7-year weight change trajectories in Roux-en-Y gastric bypass patients

Background: Weight change trajectories after weight-loss surgery may vary significantly. Objectives: This study evaluated the weight trajectories of Roux-en-Y gastric bypass (RYGB) patients and identified the distinct clinical, behavioral, and demographic features of patients by trajectory. Setting: Data from 2918 RYGB patients from a comprehensive medical center between January 2004 and November 2016 were included. Methods: This retrospective, observational study used data for RYGB patients up to year 7 postsurgery. Group-based trajectory models were fitted for percentage weight change. Variables evaluated by trajectory included age, sex, diagnoses, medications, smoking, presurgical body mass index, preoperative weight loss, and early postoperative weight loss. Results: Of 3215 possible patients, 2918 (90.8%) were included (mean age=46.2 +/- 11.2 yr, body mass index = 46.9 +/- 7.9 kg/m(2) at the time of surgery). Three weight change trajectories were identified (above average, average, and below average). Mean percentage weight change at the nadir for the above average group was -42.85% +/- 5.7% compared with -31.57% +/- 5.0% in the average group and -22.74% +/- 5.7% in the below average group. Compared with the above average group, the below average group was more likely to be male (odds ratio [OR] = 2.40, P < .0001) and have diabetes (noninsulin users, OR = 2.08, P < .0001), but less likely to have a smoking history (OR = .62, P = .0007) or take sleep medications (OR = .50, P = .005). Below average group patients had a lower BMI at the time of surgery (OR =.91, P < .0001). Lower initial weight loss postsurgery was associated with a greater chance of a poorer weight outcomes (OR = 1.64, P < .0001). Conclusion: Select clinical, demographic, and behavioral factors may increase or decrease the chance for better weight loss after RYGB. (C) 2018 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.