Abstract
We describe a unique case of hyperphosphatemia associated with a very high bone turnover rate in a 51-year-old postmenopausal woman with undiagnosed anorexia nervosa (AN) who presented with a low-trauma hip fracture. In view of her severely malnourished state, she was not fit for surgery. She was treated according to a refeeding protocol that mandated bed rest. Contrary to expectation, she developed sustained hyperphosphatemia and borderline hypercalcemia. Bone remodelling markers, both resorption and formation, were markedly elevated. Parathyroid hormone (PTH) was low-normal at 1.7 pmol/L, C-terminal fibroblast growth factor 23 (FGF23) was high at 293 RU/ml, but tubular maximum reabsorption of phosphate (TmPO4/GFR) was elevated at 1.93 mmol/L. Denosumab 60 mg was administered that was followed by: rapid normalisation of serum phosphate; normalisation of resorption markers, transient hypocalcaemia with secondary hyperparathyroidism, and normalisation of both TmPO4/GFR and C-terminal FGF23. We speculate that prolonged immobilization as part of AN management led to a high remodelling state followed by hyperphosphatemia and high-normal calcium with appropriate suppression of PTH and that marked hyperphosphatemia and high TmP/GFR despite high FGF23 indicates the necessity of PTH adequacy for excess FGF23 to lower TmP/GFR.
Similar content being viewed by others
References
American Psychiatric Association (1994) Quick reference to the diagnostic criteria from DSM-IV-TR. American Psychiatric Association, Washington
Lucas AR, Beard CM, O'Fallon WM, Kurland LT (1991) 50-year trends in the incidence of anorexia nervosa in Rochester, Minn.: a population-based study. Am J Psychiatry 148:917–922
Grinspoon S, Thomas E, Pitts S, Gross E, Mickley D, Miller K, Herzog D, Klibanski A (2000) Prevalence and predictive factors for regional osteopenia in women with anorexia nervosa. Ann Intern Med 133:790–794
Nagata JM, Golden NH, Leonard MB, Copelovitch L, Denburg MR (2017) Assessment of sex differences in fracture risk among patients with anorexia nervosa: a population-based cohort study using the health improvement network. J Bone Miner Res 32:1082–1089
The Royal College of Psychiatrists (2014) MARSIPAN: Management of really sick patients with anorexia nervosa. 2nd edn
Fukuoka H, Nishimura Y, Haruna M, Suzuki Y, Oyama K, Igawa S, Sekiguchi C, Murai T, Shigematsu T, Sudoh M, Akimura H, Gunji A (1997) Effect of bed rest immobilization on metabolic turnover of bone and bone mineral density. J Gravit Physiol 4:S75–S81
Bikle DD, Halloran BP (1999) The response of bone to unloading. J Bone Miner Metab 17:233–244
Doty SB, DiCarlo EF (1995) Pathophysiology of immobilization osteoporosis. Curr Opin Orthop 6:45–49
Gossiel F, Paggiosi MA, Naylor KE, McCloskey EV, Walsh J, Peel N, Eastell R (2019) The effect of bisphosphosphonates on bone turnover and bone balance in postmenopausal women with osteoporosis: the T-score bone marker approach in the TRIO study. Bone 131:115158
Yoon BH, Yu W (2018) Clinical utility of biochemical marker of bone turnover: fracture risk prediction and bone healing. J Bone Metab 25:73–78
Erben RG, Andrukhova O (2015) FGF23 regulation of renal tubular solute transport. Curr Opin Nephrol Hypertens 24:450–456
Geller JL, Khosravi A, Kelly MH, Riminucci M, Adams JS, Collins MT (2007) Cinacalcet in the management of tumor-induced osteomalacia. J Bone Miner Res 22:931–937
Crowley RK, Kilbane M, King TF, Morrin M, O'Keane M, McKenna MJ (2014) Hungry bone syndrome and normalisation of renal phosphorus threshold after total parathyroidectomy for tertiary hyperparathyroidism in X-linked hypophosphataemia: a case report. J Med Case Rep 8:84
McKenna MJ, Martin-Grace J, Crowley R, Twomey PJ, Kilbane MT (2019) Congenital hypophosphataemia in adults: determinants of bone turnover markers and amelioration of renal phosphate wasting following total parathyroidectomy. J Bone Miner Metab 37:685–693
Smith D, Murray BF, McDermott E, O'Shea D, McKenna MJ, McKenna TJ (2005) Hungry bones without hypocalcaemia following parathyroidectomy. J Bone Miner Metab 23:514–515
Misra M, Miller KK, Bjornson J, Hackman A, Aggarwal A, Chung J, Ott M, Herzog DB, Johnson ML, Klibanski A (2003) Alterations in growth hormone secretory dynamics in adolescent girls with anorexia nervosa and effects on bone metabolism. J Clin Endocrinol Metab 88:5615–5623
Lieberman SA, Holloway L, Marcus R, Hoffman AR (1994) Interactions of growth hormone and parathyroid hormone in renal phosphate, calcium, and calcitriol metabolism and bone remodeling in postmenopausal women. J Bone Miner Res 9:1723–1728
Takuwa Y, Yamamoto M, Matsumoto T, Hata K, Ogata E (1986) Hyperphosphatemia after surgical correction of hypercortisolism in patients with Cushing's syndrome. Miner Electrolyte Metab 12:119–124
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflicts of interest
Dr. McKenna has received fees for lectures or advice from: Amgen, Clonmel Healthcare, Mylan, Pharmacosmos and UCB. None the other authors have any disclosures.
Additional information
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Kilbane, M., Crowley, R., Twomey, P. et al. Anorexia Nervosa with Markedly High Bone Turnover and Hyperphosphatemia During Refeeding Rectified by Denosumab. Osteoporos Int 31, 1395–1398 (2020). https://doi.org/10.1007/s00198-020-05307-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00198-020-05307-1