ESPE Yearbook of Paediatric Endocrinology

To read the full abstract: N Engl J Med. 2019;380(22):2136–2145

These authors describe the 5-year follow-up of a multicenter patient cohort of adolescents with severe obesity who underwent gastric bypass surgery to lose weight and improve cardiometabolic risk factors (the Teen-LABS study; n=161, age 13–19 years at time of surgery). They compared these data with a similar but independent study of obese adults who underwent gastric bypass surgery (the LABS study; n=379, 25–50 years at time of surgery). Data on weight loss, health outcomes, and adverse events were assessed. Both, adolescents and adults achieved marked weight loss five years after surgery, but adolescents had significantly more frequent remission of pre-existing Type 2 diabetes and hypertension.

Bariatric surgery is the most effective treatment option to achieve long-term weight loss in obese adults (1). Importantly, bariatric surgery leads to resolution of major obesity-related comorbidities in a significant proportion, but not in all patients. Prognostic indicators for improvements in comorbidities are: shorter pre-surgery duration of Type 2 diabetes; higher beta-cell function; and probably also shorter pre-surgery duration of hypertension. Therefore, the authors hypothesized that bariatric surgery in obese adolescents would yield higher rates of remission of comorbidities than in adults who had been obese since their adolescent years (BMI ≥30 kg/m² at 18 years or younger). Indeed, comparing the outcomes of two large patient cohorts revealed important insights.

Both groups achieved significant weight loss at five years follow-up (−26% in adolescents; −29% in adults), but adolescents were more likely than adults to have remission of diabetes (relative risk 1.27, 95% CI: 1.03–1.57; P=0.03). Furthermore, adolescents were 51% more likely than adults to achieve remission of presurgical hypertension (relative risk 1.51, 95% CI: 1.21–1.88; P<0.001). However, these benefits came at a price: there was a small 5-year all-cause mortality rate (1.9% in adolescents; 1.8% in adults; two deaths in the adolescent cohort related to drug overdose), a higher rate of abdominal reoperations in adolescents (19/500 person years) compared to adults (10/500 person years), and a higher rate of micronutrient deficiencies in adolescents. This study adds important information for clinical decision making on the optimal age for bariatric surgery. But, still longer-term follow-up studies are needed to determine lifetime risks and benefits of bariatric surgery.

Due to the paucity of long-term data, it is impossible to fully determine the risk-benefit of bariatric surgery in adolescents. Adding to this challenge, BMI and age cutoffs for surgery are arbitrary and vary between guidelines. Most agree that the situation is complex and requires a mindful, informed approach. All adolescents should be cared for by multidisciplinary teams in centers with expertise in adolescent extreme obesity and bariatric surgery. Conventional treatment approaches should be exhausted before considering surgery. Measures to improve patient understanding of the procedure and lifestyle changes, as well as compliance, need to be implemented in a preoperative treatment program. Risk-benefit has to be considered on a case-by-case basis, keeping in mind that full information on long-term risks is currently unavailable.

Recently published recommendations by the German Working Group on Obesity in Children and Adolescents, an expert committee commissioned by the German Association for the Study of Obesity and the German Society for Pediatrics and Adolescent Medicine (2) may help to decision making in individual patients. The recommendations call for a standardized pre- and postsurgical treatment program to improve outcomes and reduce risk of adverse effects, and this has recently been implemented at five university centers in Germany.

References: 1. Colquitt JL, Pickett K, Loveman E, Frampton GK. Surgery for weight loss in adults. Cochrane Database of Systematic Reviews. 2014(8):Cd003641.

2. M. Wabitsch B. Lennerz: Safety of Bariatric Surgery in Adolescents. In Metabolism and Pathophysiology of Bariatric Surgery. Edited by V.R. Preedy RR, C. R. Martin. London: Elsevier; 2016: 199–206.