Weight loss, adverse events, and loss to follow-up after gastric bypass in young versus older adults: A Scandinavian Obesity Surgery Registry study.

BACKGROUND: Young adults display particularly poor weight loss in behavioral obesity treatment; nonetheless, they have seldom been included in bariatric research. OBJECTIVES: To compare weight loss, adverse events, and loss to follow-up in young (18-25 yr) versus older (≥26 yr) adults up to 5 years after Roux-en-Y gastric bypass. SETTING: Nationwide, register-based study, Sweden. METHODS: Prospective registry data (Scandinavian Obesity Surgery Register) were analyzed in young (22.2 yr [standard deviation (SD): 2.1], 81.6% women, mean body mass index 43.7 kg/m2 [SD: 5.4]) and older (42.6 years [SD: 9.6], 82.0% women, mean body mass index 43.4 kg/m2 [SD: 5.0]) adults undergoing Roux-en-Y gastric bypass. Groups were matched for body mass index, sex, and year of surgery. Regression analyses and mixed models were used to compare outcomes between groups. RESULTS: A total of 369 young (37.0% of eligible) and 2210 older (46.1%) adults attended the 5-year follow-up. At this time, weight loss was 31.8% in young and 28.2% in older adults (P < .001), with a serious adverse event (Clavien-Dindo ≥3b) being reported in 52 (14.1%) young and 153 (6.9%) older adults (odds ratio = 2.06, 95% confidence interval: 1.45-2.92, P < .001). Loss to follow-up was higher in young versus older adults throughout the study period (range of relative risk = 1.16-1.89, P < .001). CONCLUSIONS: While young adults displayed at least equal weight loss as older adults, rates of adverse events were approximately doubled, and loss to follow-up rates were higher. Future studies on the significance of and the etiology behind the higher incidence of serious adverse events are needed. Intensified clinical contact post Roux-en-Y gastric bypass should have the potential to further improve outcomes in young adults.