Lee Mi Young, Park Jae Hyun, Bae Keum Seok, Jee Yong Gwan, Ko An Na, Han Yong Jea, Shin Jang Yel, Lim Jung Soo, Chung Choon Hee, Kang Seong Joon
Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.
Department of Surgery, Yonsei University Wonju College of Medicine, Wonju, Korea.
Ann Surg Treat Res. 2014 Feb;86(2):55-60. doi: 10.4174/astr.2014.86.2.55. Epub 2014 Jan 22.
Current management for patients with differentiated thyroid cancer includes near total thyroidectomy and radioactive iodine therapy followed by administration of supraphysiological doses of levothyroxine (L-T4). Although hyperthyroidism is a well known risk factor for osteoporosis, the effects of L-T4 treatment on bone mineral density (BMD) in patients with thyroid cancer do not appear to be as significant as with endogenous hyperthyroidism. In this study, we evaluated the impact of long-term suppressive therapy with L-T4 on BMD and bone turn over markers in Korean female patients receiving L-T4 suppressive therapy.
We enrolled 94 female subjects (mean age, 50.84 ± 11.43 years) receiving L-T4 after total or near total thyroidectomy and radioactive iodine therapy for thyroid cancer (mean follow-up period, 12.17 ± 4.27 years). The subjects were divided into three groups by thyroid stimulating hormone (TSH) level (group 1 with TSH level ≤0.001 µIU/mL, group 2 with TSH level between 0.001 and 0.17 µIU/mL, group 3 with TSH level >0.17 µIU/mL) and four groups by quartile of free T4 level. L-T4 dosage, BMD (examined by dual-energy x-ray absorptiometry), and bone turnover markers were evaluated according to TSH and free T4 levels.
No significant decrease was detected in BMD or bone turnover markers according to TSH level or free T4 level. Also, the prevalence of osteoporosis and osteopenia was not different among groups.
Long-term L-T4 suppressive therapy after thyroid cancer management did not affect bone density or increase the prevalence of osteoporosis even though TSH levels were supraphysiologically suppressed.
目前分化型甲状腺癌患者的治疗方法包括甲状腺近全切除术、放射性碘治疗，随后给予超生理剂量的左甲状腺素（L-T4）。虽然甲状腺功能亢进是骨质疏松症的一个众所周知的危险因素，但L-T4治疗对甲状腺癌患者骨密度（BMD）的影响似乎不如内源性甲状腺功能亢进显著。在本研究中，我们评估了长期L-T4抑制治疗对接受L-T4抑制治疗的韩国女性患者骨密度和骨转换标志物的影响。
我们纳入了94名女性受试者（平均年龄50.84±11.43岁），她们因甲状腺癌接受了全甲状腺或近全甲状腺切除及放射性碘治疗后接受L-T4治疗（平均随访期12.17±4.27年）。根据促甲状腺激素（TSH）水平将受试者分为三组（1组TSH水平≤0.001 μIU/mL，2组TSH水平在0.001至0.17 μIU/mL之间，3组TSH水平>0.17 μIU/mL），根据游离T4水平四分位数分为四组。根据TSH和游离T4水平评估L-T4剂量、骨密度（通过双能X线吸收法检测）和骨转换标志物。
根据TSH水平或游离T4水平，未检测到骨密度或骨转换标志物有显著下降。此外，各组骨质疏松和骨量减少的患病率没有差异。
甲状腺癌治疗后长期L-T4抑制治疗即使TSH水平受到超生理抑制，也不会影响骨密度或增加骨质疏松的患病率。
