Hypoparathyroidism

Abstract

Background: Hypoparathyroidism is a rare endocrine disorder characterized by hypocalcemiaand low or undetectable levels of parathyroid hormone.Methods: This review is an evidence-based summary of hypoparathyroidism in terms of relevantpathophysiological, clinical, and therapeutic concepts.Results: Many clinical manifestations of hypoparathyroidism are due to the lack of thephysiological actions of parathyroid hormone on its 2 major target organs: the skeleton andthe kidney. The skeleton is inactive, accruing bone without remodeling it. The kidneys losethe calcium-conserving actions of parathyroid hormone and, thus, excrete a greater fractionof calcium. Biochemical manifestations, besides hypocalcemia and low or undetectable levelsof parathyroid hormone, include hyperphosphatemia and low levels of 1,25-dihydroxyvitaminD. Calcifications in the kidney, brain, and other soft tissues are common. Removal of, ordamage to, the parathyroid glands at the time of anterior neck surgery is, by far, the most likelyetiology. Autoimmune destruction of the parathyroid glands and other genetic causes representmost of the other etiologies. Conventional treatment with calcium and active vitamin D canmaintain the serum calcium level but high doses may be required, adding to the risk of longterm soft tissue calcifications. The advent of replacement therapy with recombinant humanPTH(1-84) represents a major step in the therapeutics of this disease.Conclusions: Advances in our knowledge of hypoparathyroidism have led to greaterunderstanding of the disease itself and our approach to it.