Effect of postoperative thyrotropin suppression on bone mineral density in postmenopausal women with differentiated thyroid carcinoma

Abstract

Objective To investigate the effect of postoperative TSH suppression on bone mineral density (BMD) in postmenopausal women with DTC. Methods Postmenopausal women with postoperative DTC underwent thyroid residual ablation or 131I treatment for metastases at Xin Hua Hospital between September 2009 and December 2014 were enrolled and followed for 2 years. They were divided into suppressive TSH group (median TSH<0.30 mU/L; group 1) and non-suppressive group (median TSH≥0.30 mU/L; group 2). Lumber 1-4 BMD levels (T scores) were measured by a dual energy X-ray absorptiometry bone densitometer at baseline, 1 year and 2 years after treatment. All patients had calcium and vitamin D supplementation after TSH suppression. The T scores were compared with Mann-Whitney u test and Kruskal-Wallis test. Results A total of 126 patients were enrolled and followed up for 2 years, including 65 with average age (57.65±6.65) years in group 1 and 61 with average age (56.19±7.17) years in group 2. The T scores in group 1 and group 2 at baseline were -1.70(-2.30, -0.55) and -1.30(-2.10, -0.30)(z=-1.660, P>0.05). The difference of T scores was significant in group 1 at baseline, 1-year follow-up and 2-year follow-up (-2.25(-2.48, -0.83), -1.95(-2.70, -0.60); H=6.244, P 0.05). The T values were different between the 2 groups both in 1-year follow-up and 2-year follow-up (z values: -2.170, -2.160, both P<0.05). Conclusions TSH suppression significantly increases the risk of postoperative osteoporosis. The BMD should be followed up annually in postmenopausal DTC patients. Key words: Thyroid neoplasms; Menopause; Bone density; Thyrotropin