Gastric bypass surgery achieves dramatic weight loss in severely obese teenagers and helps them maintain a lower body weight for more than five years of follow-up but with high rates of nutritional deficiencies, show two studies providing long term data on the impact of obesity surgery in this age group.12
Around 30% of adolescents in the US and 22-25% in Europe are overweight or obese, and one in 20 children and adolescents in the US (6.3%) is severely obese—defined as having a body mass index (BMI) of 40 or over (around 100 lb (45 kg) overweight). Lifestyle modification and medical treatment have little effect in this age group because of poor adherence, and access to surgery is limited, partly because of a lack of evidence on the long term benefits and risks.
The first study prospectively followed up 58 young people aged 13-21 (mean age 17.1) from a total of 74 who had undergone Roux en Y gastric bypass for clinical severe obesity (mean BMI 58.5 kg/m2) at a US academic medical centre.1
The results, reported in the Lancet Diabetes and Endocrinology, showed that their mean BMI fell by 29.2% (standard deviation 13.7%) after a mean follow-up of 8.0 years (range 5.4 to 12.5). The prevalence of raised blood pressure fell significantly, from 27% at baseline to 16% at follow-up (P=0.001), and reductions were also seen in type 2 diabetes (16% v 2%; P=0.03) and dyslipidaemia (86% v 38%; P<0.001).
Side effects at follow-up included mild anaemia, which occurred in nearly half (46%) of study participants but did not require treatment. A similar proportion (48%) had hyperparathyroidism, and eight young people (16%) had low levels of vitamin B12.
The second study prospectively followed up 81 adolescents aged 13-18 (mean age 16.5) with a m...0.001).