Bone Mineral Density, Parathyroid Hormone, and Vitamin D After Gastric Bypass Surgery: a 10-Year Longitudinal Follow-Up

Background: The aim of the present study was to study longitudinal changes in bone mineral density (BMD), vitamin D, and parathyroid hormone (PTH) levels in females over a 10-year period after laparoscopic Roux-en-Y gastric bypass (LRYGB). Methods: Twenty-three women, mean age 43.4 ± 8.7 years and mean body mass index (BMI) 44.6 ± 5.17 kg/m at baseline, were included. BMD, BMI, S-calcium, S-25(OH)-vitamin D, and fP-PTH were measured preoperatively and 2, 5, and 10 years postoperatively. Results: Ten years after surgery, BMD of the spine and femoral neck decreased by 20% and 25%, respectively. Changes in serum levels of vitamin D, PTH, and calcium over the same period were small. Conclusion: After LRYGB with subsequent massive weight loss, a large decrease in BMD of the spine and femoral neck was seen over a 10-year postoperative period. The fall in BMD largely occurred over the first 5 years after surgery.