Bone Mineral Density in Women Receiving Thyroxine Suppressive Therapy for Differentiated Thyroid Carcinoma

甲狀腺素壓抑治療對分化型甲狀腺癌女性病患骨質密度之影響

陳振雄(Cheng-Hsiung Chen) ； 陳榮福(Jung-Fu Chen) ； 楊博堯(Bor-Yan Yang) ； 劉瑞川(Rue-Tsuan Liu) ； 董石城(Shih-Chen Tung) ； 簡文彥(Wen-Yen Chien) ； 盧永川(Yung-Chuan Lu) ； 郭銘俊(Ming-Chun Kuo) ； 謝靜蓉(Ching-Jung Hsieh) ； 王佩文(Pei-Wen Wang)

《Journal of the Formosan Medical Association》 103卷6期 (2004/06) Pp. 442-447

https://doi.org/10.29828/JFMA.200406.0009

並列摘要

Background and Purpose: Most patients with well-differentiated thyroid carcinoma have an excellent prognosis and are likely to live long enough to be subjected to osteoporosis. The purpose of this study was to investigate the consequences of treatment with a supraphysiological dose of levothyroxine (L-T4) on bone mineral density (BMD) in Taiwanese women with differentiated thyroid cancer.
Methods: A total of 69 (44 premenopausal, 25 postmenopausal) Taiwanese women with differentiated thyroid cancer were included in this retrospective study. These patients were free of disease recurrence after initial near-total thyroidectomy and I-131 radioablation, and had undergone regular L-T4 suppressive therapy for more than 3 years (mean, 7.3 ±3.0 years; range, 3 to 15 years). The degree of thyroid-stimulating hormone (TSH) suppression was determined based on the mean TSH score for each patient which was determined by analysis of all available followup TSH data, where 1 = undetectable TSH (＜ 0.2 mIU/mL); 2 = subnormal TSH (0.2 to 0.39 mIU/mL); 3 = normal TSH (0.4 to 4.0 mIU/mL); and 4 = elevated TSH (＞ 4.0 mIU/mL). The patients were divided into a full TSH suppression group with a mean TSH score in the range 1.0 to 1.99, and a partial TSH suppression group with a mean TSH score in the range 2.0 to 2.99. BMD was measured by dual-energy X-ray absorptiometry at the lumbar spine, femoral neck, Ward’s triangle and total hip. Comparisons between subgroups of patients and controls were performed by unpaired t test. Correlation between BMD and other clinical variables was assessed by Pearson’s correlation analysis.
Results: Postmenopausal patients (aged 57.7 ±6.9 years) had significantly higher serum calcium levels and decreased BMD at all sites of the spine and hip as compared with premenopausal patients (aged 38.6 ±6.7 years) with similar BMI and duration of TSH suppression. Comparison of BMD between postmenopausal patients and BMI- and agematched controls revealed that the patient group had decreased BMD at all sites of measurement, although this difference was not significant. This phenomenon was not observed in the premenopausal patients. Furthermore, when BMD was compared between patients categorized as having full and partial suppression of TSH, only patients with full suppression in the postmenopausal group showed a tendency to lower BMD. There was a strong correlation of BMD with age, BMI and serum calcium level. However, no correlation was found between BMD and degree of TSH suppression or duration of L-T4 suppression therapy.
Conclusion: Women with differentiated thyroid cancer who had long-term (mean, 7.3 ±3.0 years) L-T4 therapy and suppressed TSH levels had no evidence of lower BMD. However, patients with full suppression in the postmenopausal group showed a tendency towards lower BMD. Therefore, careful monitoring of BMD in postmenopausal women during suppression therapy is mandatory.

並列關鍵字

Adenocarcinoma ； Bone density ； Lumbar vertebrae ； radiography ； Thyroid neoplasms ； Thyroxine