Laparoscopic Roux-en-Y gastric bypass in adolescents with severe obesity: a prospective five-year Swedish nationwide study (AMOS)

BACKGROUND: Severe obesity in adolescence is associated with reduced life expectancy and impaired quality of life. Long-term benefits of conservative treatments in adolescents are limited, while short-term outcomes of adolescent bariatric surgery are promising. This study aimed to report 5-year outcomes following Roux-en-Y gastric bypass (RYGB) in adolescents, compared with conservatively treated adolescents and adults undergoing RYGB. METHODS: A nationwide prospective non-randomised controlled study of adolescents (13–18 years) with severe obesity undergoing RYGB, a matched adolescent control group undergoing conservative treatment, and an adult comparison group undergoing RYGB. The primary outcome measure was change in weight over 5 years. Multilevel mixed-effect regression models were used to assess longitudinal changes. Healthcare usage was analysed with linear regression together with nonparametric bootstrapping. FINDINGS: Eighty-one adolescents with baseline age 16·5 years (SD 1·2), weight 132·8 kg (SD 22·1) and body mass index (BMI) 45·5 kg/m(2) (SD 6·1) underwent RYGB. Five-year weight change was −36·8 kg (95% CI −40·9 to −32·8) resulting in a BMI reduction of 13·1 kg/m(2), although weight loss <10% occurred in 11%. Comorbidities and cardiovascular risk factors resolved in 74–100%: type 2 diabetes (3/3), disturbed glucose homeostasis (18/21), dyslipidaemia (43/52), elevated blood pressure (11/12), inflammation (hs-CRP ≥ 2 mg/L; 45/61) and elevated liver enzymes (19/19), each comparing favourably with adolescent controls at 5 years. Functional (SF-36) and obesity-specific (OP-14) quality of life improved in the adolescent RYGB group (mean difference 4·2, p=0·006 and −9·9 p=0·009). Twenty RYGB participants (25%) underwent additional abdominal surgery for complications of surgery or rapid weight loss, 72% demonstrated some nutritional deficiency, and healthcare consumption increased. Mean BMI increased in control adolescents (3·3 kg/m(2,) 95% CI 1·9 to 4·8), while BMI change in adults was similar to surgical adolescents (mean difference 0·8 kg/m(2), 95% CI −1·1 to 2·8). Twenty adolescent controls (25%) underwent bariatric surgery within 5 years. INTERPRETATION: Adolescents with severe obesity undergoing RYGB experienced substantial weight loss over 5 years, alongside improvements in comorbidities, risk factors and quality of life. Surgical intervention was, however, associated with additional surgical interventions and nutritional deficiencies. Non-surgical treatment was associated with weight gain and 25% underwent bariatric surgery within 5 years.