Adlin E V, Maurer A H, Marks A D, Channick B J
Department of Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania 19140.
Am J Med. 1991 Mar;90(3):360-6. doi: 10.1016/0002-9343(91)90577-k.
To determine if bone mineral density is decreased in postmenopausal women treated with 1-thyroxine, and, if any decrease is observed, whether it is related to overtreatment with thyroid hormone, to deficiency of calcitonin, or to other factors.
The study consisted of 19 postmenopausal women between 50 and 75 years of age treated with 1-thyroxine for 5 years or longer, and 19 matching control subjects with no thyroid disease. Bone mineral density of the spine and hip was measured by dual-photon absorptiometry. Plasma calcitonin concentrations and serum thyroid hormone levels were determined by radioimmunoassays.
The 1-thyroxine-treated women had lower bone density in the lumbar spine (1.013 g/cm2 [95% confidence interval, 0.945 to 1.081] versus 1.134 g/cm2 [1.026 to 1.242], p = 0.043); in the femoral neck (0.736 g/cm2 [0.694 to 0.778] versus 0.809 g/cm2 [0.747 to 0.872], p = 0.040); in Ward's triangle (0.576 g/cm2 [0.530 to 0.623] versus 0.694 g/cm2 [0.617 to 0.770], p = 0.011); and in the trochanteric area (0.626 g/cm2 [0.581 to 0.672] versus 0.722 g/cm2 [0.651 to 0.794], p = 0.027). The maximal increase in calcitonin following calcium infusion was 1.37 ng/L (95% confidence interval, -0.44 to 3.17) in the 1-thyroxine-treated patients versus 18.8 ng/L (95% confidence interval, 10.0 to 27.5) in normal women, p less than 0.001. The average dose of 1-thyroxine was 120 micrograms/day; 16 of the 19 patients had normal serum thyroxine levels. However, TSH levels were low in 13 of the 19, suggesting that 1-thyroxine treatment was supraphysiologic. Seven of the 19 patients had a history of hyperthyroidism in the distant past; these patients, considered separately, had significantly reduced bone density in the hip. The other 12 patients, considered separately, did not have a statistically significant loss of bone density.
Long-term 1-thyroxine therapy is associated with decreased density of the spine and hip. Since subclinical hyperthyroidism, decreased calcitonin responsiveness, and a history of hyperthyroidism were demonstrated in some or all of these patients, these factors must be considered as possible causes of the decreased bone density.
确定接受左旋甲状腺素治疗的绝经后女性骨矿物质密度是否降低，若观察到有降低，其是否与甲状腺激素过度治疗、降钙素缺乏或其他因素有关。
本研究包括19名年龄在50至75岁之间、接受左旋甲状腺素治疗5年或更长时间的绝经后女性，以及19名无甲状腺疾病的匹配对照者。采用双能X线吸收法测量脊柱和髋部的骨矿物质密度。通过放射免疫分析法测定血浆降钙素浓度和血清甲状腺激素水平。
接受左旋甲状腺素治疗的女性腰椎骨密度较低（分别为1.013g/cm²[95%可信区间，0.945至1.081]与1.134g/cm²[1.026至1.242]，p = 0.043）；股骨颈骨密度较低（分别为0.736g/cm²[0.694至0.778]与0.809g/cm²[0.747至0.872]，p = 0.040）；沃德三角区骨密度较低（分别为0.576g/cm²[0.530至0.623]与0.694g/cm²[0.617至0.770]，p = 0.011）；转子区骨密度较低（分别为0.626g/cm²[0.581至0.672]与0.722g/cm²[0.651至0.794]，p = 0.027）。左旋甲状腺素治疗组患者静脉注射钙剂后降钙素的最大升高幅度为1.37ng/L（95%可信区间，-0.44至3.17），而正常女性为18.8ng/L（95%可信区间，10.0至27.5），p＜0.001。左旋甲状腺素的平均剂量为120μg/天；19名患者中有16名血清甲状腺素水平正常。然而，19名患者中有13名促甲状腺激素水平较低，提示左旋甲状腺素治疗为超生理剂量。19名患者中有7名既往有甲亢病史；单独考虑这些患者时，其髋部骨密度显著降低。单独考虑另外12名患者时，其骨密度无统计学意义的降低。
长期左旋甲状腺素治疗与脊柱和髋部骨密度降低有关。由于部分或所有这些患者存在亚临床甲亢、降钙素反应性降低及甲亢病史，这些因素必须被视为骨密度降低的可能原因。
