Hypoparathyroidism - Descriptive Results of a Large Retrospective Austrian Cohort

Presentation Number: FRI 327
Date of Presentation: April 1st, 2016

Verena Schwetz*1, Martin Kern1, Andrea Bradatsch2, Christian Trummer1, Gerhard Wolf2, Thomas R Pieber3, Jutta Claudia Piswanger-Soelkner1, Harald Dobnig4 and Karin Amrein1
1Medical University of Graz, Graz, Austria, 2Medical University of Graz, 3Medical University of Graz, Austria, 4Thyroid Endocrinology Osteoporosis Institute Dobnig, Graz, Austria

Abstract

Background

Chronic hypoparathyroidism is a hormone disorder that is typically caused by removal or damage to the parathyroid glands during or after neck surgery. Other less frequent causes include genetic and autoimmune disorders. Hypoparathyroidism substantially impacts quality of life for many patients because it causes a multitude of symptoms and requires chronic medication. However, the degree of decreased quality of life of patients with hypoparathyroidism is often underestimated. Current standard therapy is only symptomatic using primarily calcium and native/active vitamin D in greatly varying individual doses. There are to date no guidelines and hypoparathyroidism remains one of the last endocrinopathies not being treated with the missing hormone. In the future the parenteral application of parathyroid hormone may play a role.

Methods

In this retrospective study, 120 patients with hypoparathyroidism were identified at the Division of Endocrinology and Metabolism at the Medical University of Graz between 2004 and 2015, using the routine patient data management system. Patients were included if they had parathyroid hormone levels in the low or below the normal range (<25 pg/ml) in addition to a relevant diagnosis.

Results

The cohort included mostly women (n=94, 78 %). The mean age at diagnosis was 55 years. Mean total serum calcium was 2.09 mmol/l +/- 0.32. 46 % of the patients had hypocalcemic and 2.5 % hypercalcemic values. Paraesthesia and tetany were significantly more frequent in patients with low ionized calcium (p<0.05). This was not the case for low total serum calcium levels (p=0.53). Overall, 66 % complained about tetany at least once and therapy was significantly more often modified in these patients (p<0.01). 88 % of the patients had postoperative hypoparathyroidism. Although almost half of the patients were diagnosed within the first year after surgery, median time from surgery to diagnosis was 5.5 years with a maximum of more than 60 years, making a second hit-theory (e.g. radioiodine therapy) at least in some patients likely.

Conclusion

The high rates of tetany and paraesthesia suggest that patients with persistent hypoparathyroidism often remain symptomatic despite current standard treatment. Individualized therapy also based on clinical symptoms with sufficient doses of calcium, cholecalciferol and calcitriol may lead to substantial improvement. We suggest that in many cases of postoperative etiology, a second hit such as radioiodine therapy or atherosclerosis leads to overt hypoparathyroidism.

 

Nothing to Disclose: VS, MK, AB, CT, GW, TRP, JCP, HD, KA