Decreased Bone Density and Strength in Young People After Bariatric Surgery: How Much Matters?

The disease of obesity impacts more than 20% of adolescents in the United States. Longitudinal data from the Teen‐LABS consortium demonstrate that bariatric surgery in adolescents with severe obesity effectively reduces weight and resolves obesity‐associated comorbidities.(1) Despite these documented benefits, little is known about the impact of sleeve gastrectomy on bone health in adolescents. While obesity is associated with higher‐than‐normal bone mineral density (BMD), weight reduction after bariatric surgery is associated with a decline in BMD, likely related to skeletal unloading as well as nutritional and metabolic factors.(2) How bone pathology and fracture risk are impacted by evolving BMD after bariatric surgery remains unclear, with only a handful of studies in adults addressing this question.(3,4) Rousseau et al. found that adults undergoing bariatric surgery had increased rates of fracture both pre‐ and postoperatively, and the fracture distribution shifted from sites associated with obesity (distal lower limb) to sites associated with osteoporosis (upper limb, spine, and pelvis/hip/femur) as weight declined.(4) Moreover, different bariatric procedures may differentially impact bone metabolism and fracture risk. Sleeve gastrectomy is a procedure that decreases the size of the stomach while also altering hormones related to hunger and satiety. Roux‐en‐Y gastric bypass, in addition to these mechanisms, bypasses a portion of the small bowel and is also considered a malabsorptive procedure. Available data suggest that sleeve gastrectomy has a neutral effect on fracture risk, whereas malabsorptive procedures such as roux‐en‐Y gastric bypass are associated with an increased fracture risk.(5)