Preoperative Weight Trends in Adolescents Undergoing Metabolic and Bariatric Surgery

OBJECTIVE: Preoperative weight changes, predictors of weight changes, and subsequent implications on postoperative BMI reduction in adolescents preparing for bariatric surgery (MBS) have not been well described. METHODS: Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) consortium (prospective, observational MBS study at five centers from 2007 to 2011) participants who completed the preoperative phase within 3-9 months of initial visit were included in this analysis (n = 123). Participants were categorized into preoperative weight groups: > 1% loss, stable, or > 1% gain. Demographic, anthropometric, socioeconomic, medical, and behavioral data were analyzed. Postoperative percent BMI loss at 1, 5, and 8 years by weight group was compared. RESULTS: Preoperatively, 50% of participants lost weight, 20% remained stable, and 30% gained weight. The mean percent weight change by group was -4.2% (standard deviation [SD] 2.9%), +0.02% (SD 0.6%), and +5.2% (SD 5.3%), respectively. Eight-year postoperative BMI change was -21% (lost) and -26% (stable), compared to -15% among those who gained weight preoperatively (p = 0.11). No differences in preoperative weight-related behaviors were observed between groups. CONCLUSIONS: Most adolescents preparing for MBS maintained ±5% of their baseline weight. No statistically significant differences in postoperative BMI loss or factors predicting preoperative weight change were identified. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00474318.