Fracture Risk Following Bariatric Surgery: A Growing Problem in a Shrinking Patient

Background Obesity is reaching epidemic proportions in the US. In response, many are turning to gastric bypass surgeries to correct their weight and to decrease risk for cardiovascular disease. The most common procedure for surgical correction of obesity is the Roux-en-Y gastric bypass (RYGB). Like many other gastric bypass procedures, RYGB alters the absorption of essential vitamins and minerals in the gut. Multiple studies explored various causes of osteopenia, osteoporosis and fractures in post-operative gastric bypass patients. Is an operation used to reduce cardiovascular disease and diabetes, increasing the patient’s risk for developing fractures? Methods An extensive literature search of CINAHL, EBM Reviews, and MEDLINE, using search terms: bariatric surgery, bypass surgery, bone mineral density, fracture risk and fractures. Relevant articles were assessed for quality using the GRADE criteria. Results Three studies met inclusion criteria for this systematic review. One retrospective survey examined 167 patients, all of whom underwent the RYGB surgery, and were followed for 12-60 months post-operatively. Five percent of patients reported suffering a fracture and 7.2% were diagnosed with osteoporosis. A cross-sectional study consisted of 36 patients who had gastric bypass surgery between 1971 and 1992 in a single surgical center. Of the five subgroups, men and post-menopausal women not being treated with hormone replacement therapy, had significantly decreased bone mineral density and clinical osteopenia and osteoporosis. A prospective study of 59 women, who all underwent the RYGB procedure, found that at 3 years post-operatively, the bone mineral density showed a total decrease of 12.9±5.9% at the femoral neck and a 6.3±4.2% loss in the lumbar spine. This study mentioned estrogen as a major factor influencing bone mineral density post-operatively. Conclusion Gastric bypass surgery decreases bone mineral density. Dramatic weight losses, estrogen, nutrient deficiency, as well as others, have been suggested to influence fracture risk. The harm of increasing risk of fracture in gastric bypass patients, does not outweigh the benefits of reducing their risk for cardiovascular disease and of developing diabetes. As the link is still unclear, further research should be completed focusing on the link between gastric bypass surgery and the risk for fractures