Background/Purpose: Bariatric surgery is used to treat severe obesity. We aimed to investigate the incidence of significant bone mineral density (BMD) loss at 6 and 12 months after bariatric surgery.

Methods: Observational study performed in a specialised centre for the treatment of obesity in a University Hospital in France. Surface BMD was measured by dual x-ray absorptiometry (DEXA). A reduction of >0.03g/cm² was considered as significant.

Results: A total of 110 patients were included. A significant reduction in BMD was observed in 63.4% of patients at 6 months, and in 73.9% at 12 months after surgery. No case of osteoporosis was observed. There were 4 cases of osteopenia and one fracture post-surgery. BMD loss was related by univariate analysis to the reduction in Body Mass Index (BMI) (p<0,01), weight loss (p<0,01), fat mass (p<0,01) and lean mass (p<0,01). Multivariate analysis found a significant association between the reduction in BMD and the percent excess weight loss (odds ratio 1.11, 95% confidence interval (1.05-1.18), p<0.001).

Conclusion: There is a significant reduction in BMD at 6 months after surgery in over 60% of patients undergoing bariatric surgery. BMD loss is persistent over time, and predominantly situated at the femoral level, and strongly associated with weight loss. Systematic vitamin and calcium supplementation, as well as follow-up by DEXA scan seems appropriate, with systematic DEXA scan pre- and post-surgery, and annually thereafter until weight has stabilized.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/impact-of-bariatric-surgery-on-bone-mineral-density-observational-study-of-110-patients-followed-up-in-a-specialised-centre-for-the-treatment-of-obesity-in-france/