Long-term changes in parathyroid function after subtotal thyroidectomy for graves’ disease

Abstract
Background  Transient hypocalcemia is one of the postoperative complications of thyroidectomy for Graves’ disease, and perioperative parathyroid
hormone (PTH) assays are used to predict postoperative hypocalcemia. We evaluated long-term changes in parathyroid function
after surgery for Graves’ disease.

Methods  Serum PTH values were measured in Graves’ patients with postoperative hypocalcemia, and those patients were followed postoperatively.

Results  Subtotal thyroidectomy was performed in 275 patients with Graves’ disease. Their serum calcium levels were measured on postoperative
day (POD) 1, and patients with transient postoperative hypocalcemia were treated with calcium and vitamin D supplementation
and followed up. The amount of calcium and vitamin D supplementation was adjusted to keep the patient’s serum calcium level
within the normal range. Measurement of their serum intact PTH value on POD 1 revealed normal value in 18 patients, a below
normal level in 22, and an above normal level in the other 2. During the follow-up period, the serum iPTH values remained
normal in 12 patients, recovered to the normal level in 21 patients, and rose above the normal range in 9 patients. The serum
iPTH values of all patients eventually reached the normal range during the follow-up period. A marked difference in preoperative
serum alkaline phosphatase concentration was observed between the high-iPTH patients and the normocalcemic patients.

Conclusions  The phenomenon of an elevated serum PTH level after surgery for Graves’ disease was observed in 21% of the patients with postoperative
hypocalcemia despite the achievement of normal serum calcium levels by calcium and vitamin D supplementation.

Content Type Journal ArticleDOI 10.1007/s00268-008-9754-yAuthors
Yukiko Yano, Ito Hospital 4-3-6 Jinngumae, Shibuya Tokyo 150-8308 JapanMitsuji Nagahama, Ito Hospital 4-3-6 Jinngumae, Shibuya Tokyo 150-8308 JapanKiminori Sugino, Ito Hospital 4-3-6 Jinngumae, Shibuya Tokyo 150-8308 JapanKunihiko Ito, Ito Hospital 4-3-6 Jinngumae, Shibuya Tokyo 150-8308 JapanKoichi Ito, Ito Hospital 4-3-6 Jinngumae, Shibuya Tokyo 150-8308 Japan

Journal World Journal of SurgeryOnline ISSN 1432-2323Print ISSN 0364-2313 (Source: World Journal of Surgery)