Hypoparathyroidism is a rare disorder. It occurs after surgery for thyroid disorders, primary or secondary hyperparathyroidism, and laryngeal malignancies. The estimated number of thyroid surgeries performed in the US is >100,000 per year.[2]Patel KN, Yip L, Lubitz CC, et al. The American Association of Endocrine Surgeons guidelines for the definitive surgical management of thyroid disease in adults. Ann Surg. 2020 Mar;271(3):e21-93.
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Of these surgeries, approximately 7.6% lead to either transient (75%) or permanent (25%) hypoparathyroidism. There are approximately 8900 new cases of hypoparathyroidism in the US annually.[3]Powers J, Joy K, Ruscio A, et al. Prevalence and incidence of hypoparathyroidism in the United States using a large claims database. J Bone Miner Res. 2013 Dec;28(12):2570-6.
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The rate of postoperative hypoparathyroidism across different centers varies substantially based on the extent of surgery, indication for surgery (cancer, Graves disease), and experience of the surgeon.[4]Hauch A, Al-Qurayshi Z, Randolph G, et al. Total thyroidectomy is associated with increased risk of complications for low- and high-volume surgeons. Ann Surg Oncol. 2014 Nov;21(12):3844-52.
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Patients with the disease are, on average, in the fourth or fifth decades of life, and the majority are women.
In adults, about 75% of cases of hypoparathyroidism are postsurgical.[1]Khan AA, Bilezikian JP, Brandi ML, et al. Evaluation and management of hypoparathyroidism summary statement and guidelines from the Second International Workshop. J Bone Miner Res. 2022 Dec;37(12):2568-85.
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The remainder are of autoimmune, genetic, or rare secondary etiologies (e.g., infiltrative diseases).
Estimates of prevalence of hypoparathyroidism from international studies range from 6 to 37 per 100,000 individuals; incidence is reported to be 0.8 to 2.3 per 100,000 individuals per year.[5]Bjornsdottir S, Ing S, Mitchell DM, et al. Epidemiology and financial burden of adult chronic hypoparathyroidism. J Bone Miner Res. 2022 Dec;37(12):2602-14.
https://asbmr.onlinelibrary.wiley.com/doi/10.1002/jbmr.4675
http://www.ncbi.nlm.nih.gov/pubmed/36054571?tool=bestpractice.com
In Denmark, the prevalence of nonsurgical hypoparathyroidism is 2.3 per 100,000 individuals.[6]Underbjerg L, Sikjaer T, Mosekilde L, et al. The epidemiology of nonsurgical hypoparathyroidism in Denmark: a nationwide case finding study. J Bone Miner Res. 2015 Sep;30(9):1738-44.
https://asbmr.onlinelibrary.wiley.com/doi/10.1002/jbmr.2501
http://www.ncbi.nlm.nih.gov/pubmed/25753591?tool=bestpractice.com