Adolescents undergoing vertical sleeve gastrectomy (VSG) have fewer nutritional deficiencies than Roux-en-Y bypass (RYGB) at 5 years after the procedure, but both can produce deficiencies in iron and B12, researchers report in Clinical Gastroenterology and Hepatology. Ongoing nutrient monitoring and supplementation are recommended for all patients who receive bariatric surgery.
Bariatric surgery is an increasingly accepted treatment for severe obesity in youth, but lower adherence to supplementation and anticipated longer lifespan with altered gastrointestinal physiology could increase risk of adverse nutritional outcomes in young patients.
There have been no studies of clinical or demographic factors associated with nutritional deficiencies after bariatric surgery. Surgery type, supplementation intake, sex, and race might affect risk.
Stavra A. Xanthakos et al aimed to characterize longitudinal changes in iron status, vitamins B12 and B1, folate, vitamins A and D, albumin, and calcium homeostasis (parathyroid hormone) in adolescents (mean age, 16.5 years; mean body mass index, 52.7) more than 5 years after VSG (n=67) or RYGB (n=161) and to determine factors associated with nutritional deficiencies. The analysis was part of the observational Teen-LABS cohort study (NCT00474318), which aims to assess the short and longer-term safety and efficacy of bariatric surgery in adolescents compared to adults.
The participants’ mean body mass index decreased 23% at 5 years and did not differ significantly between procedures. But 59% of patients who received RYGB and 27% who received VSG had 2 or more nutritional deficiencies.
The most prevalent abnormality observed was hypoferritinemia (indicating iron deficiency), which affected nearly twice as many RYGB recipients by year 5 as VSG recipients. Hypoferritinemia was observed in 2.5% of patients before RYGB and 71% at 5 years after RYGB (P < .0001), and 11% of patients before VSG and 45% 5 years after VSG (P = .002).
After RYGB, but not VSG, serum concentrations of vitamin B12 significantly decreased whereas serum levels of transferrin and parathyroid hormone increased. No significant changes in serum levels of folate or vitamins A, B1, or D were found between baseline and 5 years after either procedure.
This was the first study to compare nutritional outcomes in adolescents after VSG vs RYGB. VSG is the predominant bariatric surgery performed in adolescents and adults because of limited anatomic alteration, lower operative risk, and presumed lower risk of nutritional deficits. This study provides evidence that VSG does have significantly lower nutritional risk than RYGB, but can still worsen iron status.
Xanthakos et al conclude that bariatric surgery in adolescents can increase nutritional deficiencies over 5 years, with greater risk after RYGB, particularly for iron and B12 deficiency. The findings indicate the importance of long-term nutritional monitoring in adolescents after bariatric surgery and the need to track health and quality of life as they enter adulthood, including assessments of anemia and bone health. It is imporant to determine nutritional outcomes in recipients of endoscopic sleeve and other bariatric procedures as their use increases.