Nagasaki Toshiki, Inaba Masaaki, Henmi Yasuko, Kumeda Yasuro, Ueda Misako, Tahara Hideki, Sugiguchi Shigeru, Fujiwara Shigehiko, Emoto Masanori, Ishimura Eiji, Onoda Naoyoshi, Ishikawa Tetsuro, Nishizawa Yoshiki
Department of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, 1-4-3, Asahi-machi, Abeno-ku, Osaka 545-8585, Japan.
Clin Endocrinol (Oxf). 2003 Nov;59(5):607-12. doi: 10.1046/j.1365-2265.2003.01893.x.
This case-control study was carried out to assess whether levothyroxine (L-T4) replacement might cause regression of the enhanced atherosclerosis seen in hypothyroid patients.
Intima-media thickness (IMT) in the common carotid artery (CCA) was measured from digitalized still images taken during scanning by high-resolution ultrasonography as an indicator of early atherosclerosis. Thirty-five hypothyroid patients were examined for their CCA IMT before and 1 year after normalization of thyroid function by L-T4 replacement. As control, 35 healthy subjects were enrolled from among the participants in a local health-check programme conducted at the Osaka City University Hospital.
Basal CCA IMT was significantly higher in hypothyroid patients [0.635 +/- 0.018 (mean +/- SE) mm] than in control subjects (0.559 +/- 0.021 mm, P < 0.005). After 1 year of euthyroidism, 34 out of 35 patients showed a significant decrease of CCA IMT, to 0.552 +/- 0.015 mm (P < 0.0001), a level comparable to normal controls. CCA IMT change was closely associated with basal levels of total cholesterol (r = -0.472, P= 0.0031), low-density lipoprotein (LDL) cholesterol (r = -0.441, P= 0.0076) and the total/HDL cholesterol ratio (r =-0.435, P= 0.0057), but not with any of the other variables measured except for age (r = -0.353, P= 0.0296).
This study demonstrated that L-T4 treatment might have the potential to reverse the progression of atherosclerosis in hypothyroid patients. Furthermore, it suggests that increased levels of LDL cholesterol and the total/HDL cholesterol ratio have an important role in the increased common carotid intima-media thickness in hypothyroid patients.
开展此项病例对照研究以评估左甲状腺素（L-T4）替代治疗是否可能使甲状腺功能减退患者中出现的动脉粥样硬化增强现象消退。
通过高分辨率超声扫描期间拍摄的数字化静态图像测量颈总动脉（CCA）的内膜中层厚度（IMT），作为早期动脉粥样硬化的指标。35例甲状腺功能减退患者在通过L-T4替代治疗使甲状腺功能正常化之前及之后1年接受了CCA IMT检查。作为对照，从大阪市立大学医院开展的当地健康检查项目参与者中招募了35名健康受试者。
甲状腺功能减退患者的基础CCA IMT [0.635±0.018（均值±标准误）mm]显著高于对照受试者（0.559±0.021 mm，P<0.005）。甲状腺功能正常1年后，35例患者中有34例的CCA IMT显著降低，降至0.552±0.015 mm（P<0.0001），这一水平与正常对照相当。CCA IMT变化与总胆固醇基础水平（r = -0.472，P = 0.0031）、低密度脂蛋白（LDL）胆固醇（r = -0.441，P = 0.0076）以及总胆固醇/高密度脂蛋白胆固醇比值（r = -0.435，P = 0.0057）密切相关，但与除年龄外测量的任何其他变量（r = -0.353，P = 0.0296）均无关。
本研究表明，L-T4治疗可能具有逆转甲状腺功能减退患者动脉粥样硬化进展的潜力。此外，这表明LDL胆固醇水平升高以及总胆固醇/高密度脂蛋白胆固醇比值在甲状腺功能减退患者颈总动脉内膜中层厚度增加中起重要作用。
