Poster Presentation ESA-SRB 2023 in conjunction with ENSA

Difficulty in Controlling Bone Turnover and Managing Osteoporosis After Roux-end-Y Gastric Bypass (#305)

Michael Hancock 1 , Bronwyn Stuckey 1 2 3
  1. Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Perth , WA, Australia
  2. Keogh Institute for Medical Research, Perth , WA, Australia
  3. School of Medicine , University of Western Australia, Perth , WA, Australia

Case Report

Mrs SN, a 58-year-old female, underwent Roux-en-Y gastric bypass in 2018, with substantial weight loss, 120 Kg (BMI 46) to 66.8 Kg (BMI 25). Secondary hyperparathyroidism with elevated bone turnover markers (BTMs) and vitamin D deficiency was observed (table 1), and osteopaenia 3 years post-op (figures 1-3).

Oral bisphosphonate (risedronate) caused symptomatic hypocalcaemia and was ceased. MHT (Estradot) and vitamin D supplementation were commenced and titrated, but ineffective as BTMs remain markedly elevated with progressive reduction in bone mineral density (BMD), now within osteoporosis range, 5 years post-op.

 

Discussion

Post-bariatric surgery, osteoporosis and secondary hyperparathyroidism are common complications, seen in 27% and 54% at 10 years respectively1-3. Weight loss greater than 30% excess weight loss (EWL) increases this risk, particularly approaching or exceeding BMI 25, 100% EWL, as with Mrs SN2. Bone microarchitecture is altered, particularly sites with greater periosteal bone4.

Improving secondary hyperparathyroidism with vitamin D and calcium supplementation may not alter progressive renal calcium conservation, BTMs and altered bone microarchitecture5. Normalising and supressing BTMs may be a more suitable therapeutic target, however bisphosphonate induced hypocalcaemia, and medication malabsorption can complicate this. MHT may be beneficial in post-menopausal women, but minimal published data exists. Transdermal routes or oestrogen implants may be required as trialled in Mrs SN, with sub-therapeutic oestrogen levels impacting efficacy.

Interpreting BMD is challenging, with reduced fat mass potentially lowering BMD. Degenerative osteoarthritis is common in bariatric patients, potentially increased BMD, also impacting interpretation. Mrs SN had significant osteoarthritis affected her lumbar spine, evidenced by discrepancies between spine and hip measurements.

 

Conclusions

  1. Roux-en-Y gastric bypass achieves significant weight loss, but risks osteoporosis and malnutrition.
  2. Suppression of BTMs is an important therapeutic target, however determining the optimal approach requires consideration of gender, menopausal status, and nutritional deficiencies.
  3. Physiological changes post-operatively, influence BMD interpretation. 

 

64ef34752d79e-Table+1.jpg

 64ef3afd8818a-Figure+1.jpg

64ef3afd8818a-Figure+2.jpg

64ef3afd8818a-Figure+3.jpg

  1. Blom-Høgestøl IK, Hewitt S, Chahal-Kummen M, Brunborg C, Gulseth HL, Kristinsson JA, et al. Bone metabolism, bone mineral density and low-energy fractures 10 years after Roux-en-Y gastric bypass. Bone. 2019;127:436-45.
  2. Araújo MM, Mendes MM, Costa LM, Lima RM, Lanham-New SA, Baiocchi de Carvalho KM, et al. Determinant factors of bone health after long-term of Roux-en-Y gastric bypass surgery: A cross-sectional study. Nutrition. 2023;108:111937.
  3. Schafer AL, Weaver CM, Black DM, Wheeler AL, Chang H, Szefc GV, et al. Intestinal Calcium Absorption Decreases Dramatically After Gastric Bypass Surgery Despite Optimization of Vitamin D Status. J Bone Miner Res. 2015;30(8):1377-85.
  4. Lindeman KG, Rushin CC, Cheney MC, Bouxsein ML, Hutter MM, Yu EW. Bone Density and Trabecular Morphology at Least 10 Years After Gastric Bypass and Gastric Banding. J Bone Miner Res. 2020;35(11):2132-42.
  5. Niu A, Carpenter TO, Grams JM, Bozorgmehri S, Tommasini SM, Schafer AL, et al. High dose vitamin D supplementation does not rescue bone loss following Roux-en-Y gastric bypass in female rats. Bone. 2019;127:172-80.