SAT-518 Long-term Impact of Gastric Bypass on Bone Density >10 years after Bariatric Surgery: Exceeding Physiologic Expectations

• Published in: Journal of the Endocrine Society 2019-04, Vol.3 (Supplement_1)
• Main Authors: Rushin, Claire, Lindeman, Katherine, Cheney, Michael, Hutter, Matthew, Yu, Elaine
• Format: Article
• Language: English
• Subjects: Bone and Mineral Metabolism
• ISSN: 2472-1972; 2472-1972
• DOI: 10.1210/js.2019-SAT-518

Introduction: In the initial years after bariatric surgery, Roux-en-Y gastric bypass (RYGB) leads to high-turnover bone loss and an increased risk of fractures. The long-term effects of RYGB on bone density and microarchitecture have not been defined beyond 5 years. Furthermore, there remains an open question of whether bone loss exceeds physiologic expectations for surgical weight loss. Thus, we evaluated bone mineral density (BMD) and bone microarchitecture in adults who received RYGB at least 10 years ago compared to BMI-matched controls. Methods: In this ongoing study, we recruited 24 adults who received RYGB ≥10 years ago, along with nonsurgical controls who were matched 1:1 by age, sex, race/ethnicity, and current BMI. Total body composition and areal BMD (aBMD) of the lumbar spine and proximal femur were assessed by dual energy x-ray absorptiometry (DXA). Volumetric BMD (vBMD) and bone microarchitecture at the distal radius and tibia were evaluated with high resolution peripheral QCT. Serum calcium, 25-OH vitamin D, and PTH were available in 2/3 of subjects; additional analyses are ongoing. Paired t-tests were used to compare outcomes between groups. Results: By design, the RYGB group was well-matched with controls for BMI (33 ± 6 kg/m2), age (56 ± 10 yr), sex (88% female), and race (65% white). Fat mass and lean mass were similar between RYGB and controls. Mean time since surgery was 13.7 ± 2.2 yrs in the RYGB group, and self-reported weight loss was 45 ± 19 kg. As compared to BMI-matched controls, RYGB patients had 17% lower femoral neck aBMD (p