Tohoku J. Exp. Med., 2004, 203(3)

Serum Osteocalcin Levels in Hyperthyroidism before and after Antithyroid Therapy

GULHAN BARSAL, FATMA TANELI,¹ AYSENUR ATAY, ZELIHA HEKIMSOY² and FUSUN ERCIYAS

Biochemistry and Clinical Biochemistry Laboratory, Atatürk Training Hospital, Izmir, Turkey,
¹Department of Biochemistry and Clinical Biochemistry, and ²Department of Endocrinology, Celal Bayar University School of Medicine, Manisa, Turkey

Hyperthyroidism is characterized by accelerated bone turnover, caused from direct stimulation of bone cells by increased thyroid hormones. In this study, we aimed to investigate serum osteocalcin levels as a bone formation marker, before antithyroid (propylthiouracil) therapy at hyperthyroid stage and after antithyroid therapy at euthyroid stage of the patients. Twenty four hyperthyroid patients (18 females, 6 males) and 20 (13 females, 7 males) healthy controls were included into this study. Blood and urine samples were taken before medical treatment at hyperthyroid state, and after the antithyroid therapy until the patients reached the euthyroid state. Serum alkaline phosphatase, osteocalcin, calcium, phosphorus, Free T3, Free T4, TSH and urine calcium/creatinine levels were assessed. We found a significant decrease in serum osteocalcin (p=0.006), urinary calcium/creatinine (p=0.004), and serum phosphorus (p=0.038) levels in euthyroid state in comparison to hyperthyroid state. The increases in serum bone formation marker osteocalcin and bone resorption marker urinary calcium/creatinine levels in hyperthyroid state compared to euthyroid state in our study confirmed that hyperthyroid patients have high bone turnover. We conclude that, hyperthyroid patients has high bone turnover of formation and resorption even after attainment of euthyroidism. Osteocalcin and urine calcium/creatinine are sensitive markers in documenting bone remodeling during treatment of hyperthyroidism.

keywords —— bone turnover; hyperthyroidism; osteocalcin

© 2004 Tohoku University Medical Press

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Address for reprints: Fatma Taneli, Department of Biochemistry and Clinical Biochemistry, Celal Bayar University Faculty of Medicine, Manisa, 45020, Turkey.

e-mail: fatma.taneli@bayar.edu.tr

This study was presented at 18th International Congress of Clinical Chemistry and Laboratory Medicine held in Kyoto, Japan, at 20-25 October 2002 and awarded with “Excellent Poster Kyoto Award” at the same congress.