Bone loss. An emerging problem following obesity surgery

The incidence of obesity worldwide has increased markedly in the past 2 decades, with estimates of increases of 50% in the United States alone. Research indicates that weight loss produced by diet alone is not sustained and that 75% of dieters regain most of the weight lost within 1 year and 90% within 2 years. Morbid obesity is associated with comorbid conditions, including heart disease, hypertension, diabetes, mechanical arthropathy, sleep apnea, and numerous other serious disorders and a shortened life expectancy. Because of limited success with medical management, surgical treatment of morbid obesity has been used increasingly, especially with the development of laparoscopic procedures, including Roux-en-Y gastric bypass (RYGB). RYGB is associated with low surgical mortality, marked decreased food intake, and significant, sustained weight loss. However, in this emerging, unique population there is growing appreciation that these procedures may be associated with the development of bone loss and skeletal fragility because of altered nutrient metabolism. Despite the threat of skeletal fragility and fracture, there is limited data addressing the effects of bariatric surgery on bone metabolism and bone loss.