Chosich N, LeGrand B A, Topliss D J, Stockigt J R
Ewen Downie Metabolic Unit, Alfred Hospital, Melbourne, Vic, Australia.
Thyroidology. 1989 Aug;1(2):79-83.
In order to establish the significance of subnormal, detectable TSH values in the range 0.05-0.3 mU/L by sensitive immunoradiometric assay, we assessed 3150 consecutive tests of thyroid function in which TSH was measured on 1400. Sixty TSH values (4.3%) fell in this range and in 80% of these the result was confirmed on repeat assay. Conditions associated with subnormal detectable TSH values were treated hyperthyroidism (21), nonthyroidal illness (17), euthyroid multinodular goitre (10), T4 therapy for primary hypothyroidism (7), and pituitary disease (5). At follow-up 2-15 months later, a second sample showed that TSH remained in this range in only 9 of 41 patients (22%). These findings show a frequency of TSH values intermediate between normality and the suppressed values of hyperthyroidism sufficient to compromise the value of sensitive TSH measurement as the single initial test of thyroid function. While TSH values in the subnormal detectable range rule out hyperthyroidism, such results may merit follow-up in goitrous patients, in whom such a finding can precede overt hyperthyroidism.
为了确定通过敏感免疫放射测定法测得的0.05 - 0.3 mU/L范围内低于正常可检测促甲状腺激素（TSH）值的意义，我们评估了连续3150次甲状腺功能检测，其中对1400例进行了TSH检测。60个TSH值（4.3%）落在该范围内，其中80%在重复检测时得到证实。与低于正常可检测TSH值相关的情况有：治疗中的甲状腺功能亢进（21例）、非甲状腺疾病（17例）、甲状腺功能正常的多结节性甲状腺肿（10例）、原发性甲状腺功能减退症的T4治疗（7例）以及垂体疾病（5例）。在2 - 15个月后的随访中，第二个样本显示，41例患者中只有9例（22%）的TSH仍处于该范围内。这些发现表明，TSH值的出现频率介于正常和甲状腺功能亢进症受抑制值之间，足以影响将敏感TSH测量作为甲状腺功能的单一初始检测的价值。虽然低于正常可检测范围内的TSH值可排除甲状腺功能亢进症，但对于甲状腺肿患者，此类结果可能值得随访，因为在这些患者中，这一发现可能先于明显的甲状腺功能亢进症出现。
