Pacchiarotti A, Martino E, Bartalena L, Aghini-Lombardi F, Grasso L, Buratti L, Falcone M, Pinchera A
J Endocrinol Invest. 1986 Aug;9(4):315-9. doi: 10.1007/BF03346934.
Serum free thyroxine (FT4) and free triiodothyronine (FT3) concentrations were measured in a group of 52 patients with subclinical hypothyroidism (SH) and in an equal group of age and sex-matched normal controls. SH was defined by normal total T4 (TT4) and total T3 (TT3) concentrations, normal FT4 and FT3 indices, raised TSH levels, in the absence of signs and symptoms of hypothyroidism. Serum FT4 levels averaged 6.1 +/- 1.6 pg/ml (mean +/- SD, p less than 0.001 vs controls), with values below lower normal limits in 33/52 patients; mean FT3 concentrations averaged 3.1 +/- 0.7 pg/ml (p less than 0.001 vs controls), with values below lower normal limits in 8/52 patients. The analysis of results by the Galen and Gambino predictive value model demonstrated a higher sensitivity, but a lower specificity of FT4 as compared to FT3 in the diagnosis of SH. These results indicate that FT4 should be measured in addition to TSH for the diagnosis of impending thyroid failure, thus showing that in many cases patients with so-called subclinical hypothyroidism are actually already mild hypothyroid.
对一组52例亚临床甲状腺功能减退症（SH）患者以及年龄和性别匹配的同等数量正常对照者测定了血清游离甲状腺素（FT4）和游离三碘甲状腺原氨酸（FT3）浓度。SH的定义为总T4（TT4）和总T3（TT3）浓度正常、FT4和FT3指数正常、促甲状腺激素（TSH）水平升高，且无甲状腺功能减退的体征和症状。血清FT4水平平均为6.1±1.6 pg/ml（均值±标准差，与对照组相比p<0.001），52例患者中有33例的值低于正常下限；平均FT3浓度为3.1±0.7 pg/ml（与对照组相比p<0.001），52例患者中有8例的值低于正常下限。根据盖伦和甘比诺预测值模型对结果进行分析显示，在SH的诊断中，与FT3相比，FT4具有更高的敏感性，但特异性较低。这些结果表明，为诊断即将发生的甲状腺功能衰竭，除TSH外还应测定FT4，从而表明在许多情况下，所谓亚临床甲状腺功能减退症患者实际上已经是轻度甲状腺功能减退。
