It might not be a stretch to say that childhood obesity is the leading health threat for US children in our time. But when are drastic measures, like bariatric surgery, indicated, and what are the long-term outcomes of such procedures? We now have a bit more detail on this, but as usual more questions than answers.
Source: Inge TH, Courcoulas AP, Todd MJ, et al. Weight loss and health status 3 years after bariatric surgery in adolescents. N Engl J Med. 2016;374:113-123. doi:10.1056/NEJMoa1506699. See AAP Grand Rounds commentary by Dr. Ronald Holmes (subscription required).
PICO Question: Among severely obese adolescents undergoing bariatric surgery in the United States, what are the benefits and adverse events that occur during the following three years?
Question type: Treatment
Study design: Observational
The New England Journal of Medicine is of course highly respected, though at times I've been inclined to accuse the editors of study design snobbery, since we seldom see observational studies or meta-analyses published there. So, I was a bit surprised to see this study appear. Like most observational studies, it is limited in how much we can draw from this into our clinical practice, but it's worth some attention.
The study provides 3-year follow up of 225 adolescents who underwent bariatric procedures (Roux-en-Y bypass or gastric banding) enrolled at 6 academic medical centers. They found favorable outcomes related to weight loss and to remission of type 2 diabetes, abnormal renal function, hypertension, and dyslipidemia in those affected by these conditions at study entry. However, 13% of the adolescents required additional GI surgeries (most commonly cholecystectomy), and higher rates of deficiencies of ferritin and vitamins B12 and A were present at the end of the 3-year follow-up period.
Bariatric surgery is only 1 part of a plan to correct severe obesity, the other main component being lifestyle changes. I looked in vain to find an analysis of how lifestyle changes might have been associated with the reported outcomes, including perusing the lengthy online supplements to the article. The protocol stated that all enrollees were prescribed multivitamin and micronutrient supplementation, and that adherence to these medications would be tracked, but it doesn't seem to be reported here. Likewise, I couldn't find any mention of exercise or dietary changes that also would be important to assess long-term benefits of bariatric surgery. Maybe the authors are holding back on that data for another publication.
Because this wasn't a prospective, randomized controlled trial, nor even a prospective cohort study with a historical comparison group, we don't have a control group to assess the study findings. Rather, it is simply a pre- and post-surgical comparison of their subjects. This makes it a bit more difficult to decide on the role of bariatric surgery in treatment of adolescent obesity, but at least we have some solid 3-year outcomes to guide us going forward. I look forward to reading about longer term follow-up of the subjects in this study.