You are seeing Anna Boylston in your adolescent primary care clinic today. You have been her PCP since she was 10 years-old. She is now 14 and has a history of severe obesity (current BMI 37 kg/m2). She and her family ask you about bariatric surgery options for teenagers and the long term benefits and risks. What do you tell them?
Volume of adolescent bariatric surgical cases in the United States has doubled from nearly 800 to 1600 cases during the past decade. However, prospective data on the efficacy and safety of adolescent bariatric surgery is unknown. Bariatric surgery in adolescents will likely rise, as nearly 7% of 12 to 17 year olds in the United States have severe obesity, defined as an BMI ≥ 120% of the 95th percentile or ≥ 35 kg/m2.
What are the indications for bariatric surgery in adolescents?
The American Society for Metabolic and Bariatric Surgery recommends a minimum BMI threshold of ≥35 kg/m2 with a severe comorbidity or a BMI ≥40 kg/m2 with minor comorbidities. These are similar indications to those in adults.
What is this study about?
In this week’s issue of NEJM, Inge and colleagues present their findings from a multi-center prospective observational study called Teen-LABS that evaluated the efficacy and safety outcomes of bariatric procedures in adolescents.
The trial enrolled a cohort of 242 adolescents ages 13 to 19. 161 (66%) received gastric bypass and 67 (28%) underwent sleeve gastrectomy. 14 received adjustable gastric banding, but that cohort was too small to include in the analysis. The outcomes were changes in body weight, comorbidities, quality of life, micronutrient data, and other abdominal procedures 3 years post-operatively.
Who is in the study?
75% of the patients in the analysis were teenage girls. At baseline, the mean BMI was 53 kg/m2 (ranges 34-88). 98% of the patients had a BMI > 40 kg/m2. About 13% had type 2 diabetes and 10%, pre-diabetes. Seventy-six % had dyslipidemia, over 40%, elevated blood pressure, and 17%, abnormal kidney function.
What were the results?
At 3-years post-op, participants on average lost 27% of the baseline weight. Weight reduction from either gastric bypass or vertical gastrectomy was similar (28% versus 26%). A significant portion of the cohort had remissions of their medical comorbidities (type 2 diabetes, 95%; pre-diabetes, 76%; dyslipidemia, 66%; elevated blood pressure, 74%; and abnormal kidney function, 86%).
Weight-related quality of life metrics also improved at 3-years post-op.
However, patients also experienced increased rates of metabolic abnormalities and additional abdominal procedures. The percentage of patients with low ferritin levels (5% versus 57%) and low vitamin B12 levels (3% versus 16%) increased significantly at 3 years. About 22% of patients had undergone additional intra-abdominal operations after their initial procedure at 3 years. Twenty-three % of the patients also went under endoscopic procedures during the 3-years follow-up. Both rates occurred more frequently in those that had gastric bypass versus those who had sleeve gastrectomy.
Should more adolescents with severe obesity undergo bariatric surgery?
A NEJM editorial by Dr. Caroline Apovian from Boston University School of Medicine states that the study “provides longer-term evidence that bariatric surgery can provide relief from the tremendous physical, social, and psychological burden that severe obesity causes in a growing number of American youth.” However, she cautions that longer-term (>10 year) follow-up is necessary to determine the persistence of anticipated and unanticipated complications and that primary prevention of severe obesity in adolescents also needs to be part of the solution.
What is my take-away?
Bariatric surgery in adolescents appears to result in weight reduction and a decrease in medical co-morbidities. However, the longer-term efficacy and safety requires assessment.
See a NEJM interactive graphics on the different bariatric procedures.
How does the outcome in adolescents compare with those in adults? Learn about the STAMPEDE trial comparing bariatric surgery versus conventional medical therapy in adults with type 2 diabetes.
Join a conversation with the authors of this study on the NEJM Group Open Forum, ongoing through January 20.
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James was a 2015-2016 NEJM Editorial Fellow. He recently completed fellowship in General Internal Medicine at Brigham and Women’s Hospital. He is interested in evidence-based medicine, medical education, knowledge translation, and pharmacoepidemiology.