Symons R G, Walichnowski C M, Murphy L J
Clin Chem. 1982 Feb;28(2):266-70.
The indirect indices of free-thyroxin concentration (fT4) are of limited effectiveness in diagnosing covert (mild) thyroid disease. We compared measurements of fT4 and of normalized T4 (NT4, the effective thyroxin ratio) in a group of patients being treated for thyroid disease, most of whom were clinically euthyroid. Although fT4 values correlated well with NT4, many of the patients (34% in one of the comparisons) had fT4 and NT4 values that gave different indications of thyroid status. A review of the patients' treatment and other biochemical indications revealed that measurements of fT4 were more effective in detecting mild disturbances of thyrometabolic status than were assays for NT4, total T4, total triiodothyronine, or thyrotropin. This study suggests that direct fT4 assays are particularly useful in diagnosing covert thyroid disease.
游离甲状腺素浓度（fT4）的间接指标在诊断隐匿性（轻度）甲状腺疾病方面效果有限。我们比较了一组正在接受甲状腺疾病治疗的患者的fT4和标准化T4（NT4，有效甲状腺素比值）测量值，其中大多数患者临床上甲状腺功能正常。尽管fT4值与NT4相关性良好，但许多患者（在其中一项比较中为34%）的fT4和NT4值给出了不同的甲状腺状态指示。对患者治疗情况和其他生化指标的回顾显示，与NT4、总T4、总三碘甲状腺原氨酸或促甲状腺激素检测相比，fT4测量在检测甲状腺代谢状态的轻度紊乱方面更有效。这项研究表明，直接fT4检测在诊断隐匿性甲状腺疾病方面特别有用。
