Can Serum Osteocalcin Level be Used as a Marker to Assess Bone Remodeling Status in Hyperthyroidism?

Abstract

Aims: The aim of this study was to estimate the serum osteocalcin levels before and during treatment in hyperthyroidism and to compare with healthy controls. Study Design: Case control study. Place and Duration of Study: Department of Biochemistry, Department of Endocrinology. M.S. Ramaiah medical college, Bangalore. December 2014 to May 2015. Methodology: Twenty five newly diagnosed hyperthyroid patients, Twenty five patients who are euthyroid during treatment and Twenty five healthy controls in the age group of 20-50yrs were enrolled in this study. Serum T3, T4, TSH were assayed by electrochemiluminescence and serum Osteocalcin was estimated by ELISA. Kruskal wallis test was used to compare T3, T4, TSH, osteocalcin and calcium levels among three groups. Post Hoc test was used for multiple comparisons between two groups. Results: Using Kruskal wallis test, a significant difference for T3, T4, TSH and osteocalcin values was observed among the different groups (p <0.001). Post Hoc test for multiple comparisons between two groups revealed that osteocalcin levels were significantly high in newly diagnosed hyperthyroid patients compared to controls (p=0.02) indicating high bone turnover. There was also a significant difference in osteocalcin levels between newly diagnosed hyperthyroid patients and patients who are euthyroid on treatment (p= 0.04) indicating values decreased on treatment. ROC analysis showed serum osteocalcin is a good marker for assessing bone remodeling status in hyperthyroidism. (Area under curve= 86.6 and p value = 0.001) Conclusion: Serum osteocalcin can be used to assess bone remodeling status in newly diagnosed hyperthyroidism and to identify residual bone resorption in the euthyroid state during treatment.