Rose S R, Nisula B C
Developmental Endocrinology Branch, National Institute of Child Health and Human Development, Bethesda, Maryland 20892.
J Clin Endocrinol Metab. 1989 Jun;68(6):1086-90. doi: 10.1210/jcem-68-6-1086.
We evaluated the circadian variation of serum TSH in 96 normal children, aged 5-18 yr. Blood samples were obtained hourly for 24 h, and serum TSH was measured using an immunoradiometric assay with a sensitivity of 0.2 mU/L and an intraassay coefficient of variation of 4.9%. The nadir serum TSH value, defined by the three consecutive hourly TSH concentrations having the lowest mean, occurred between 1000 and 1900 h, while the peak TSH value, defined by the three consecutive hourly TSH concentrations having the greatest mean, occurred between 2100 and 0600 h. The mean nadir serum TSH was 1.6 +/- 0.1 mU/L, and the mean peak TSH was 3.7 +/- 0.2 mU/L. The mean nocturnal TSH surge (percent increase in TSH from nadir to peak) was 144% (95% confidence limits, 50-300%) and did not correlate with serum T4, free T4, or T3 concentrations. Seventy-six children were given TRH (7 micrograms/kg). The mean peak serum TSH after TRH was 16.0 +/- 1.1 mU/L (95% confidence limits, 9.0-42.0 mU/L), and it occurred by 30 min after TRH administration in 92% of the children. The absolute peak nocturnal serum TSH and peak post-TRH serum TSH values correlated significantly (r = 0.62; P less than 0.001), while age, gender, and pubertal status did not correlate with either the nocturnal TSH surge or the TSH response to TRH. We conclude that normal children have a circadian variation of serum TSH characterized by a nocturnal TSH surge, and that the peak of serum TSH, which occurs at night, correlates with the peak serum TSH level after TRH administration.
我们评估了96名5至18岁正常儿童血清促甲状腺激素（TSH）的昼夜变化。每小时采集血样，共采集24小时，采用免疫放射分析法测定血清TSH，该方法灵敏度为0.2 mU/L，批内变异系数为4.9%。最低血清TSH值由三个连续小时的TSH浓度均值最低来定义，出现在10:00至19:00之间；而最高TSH值由三个连续小时的TSH浓度均值最高来定义，出现在21:00至06:00之间。最低血清TSH均值为1.6±0.1 mU/L，最高TSH均值为3.7±0.2 mU/L。夜间TSH平均增幅（从最低值到最高值的TSH百分比增加）为144%（95%置信区间，50 - 300%），且与血清T4、游离T4或T3浓度无关。76名儿童接受了促甲状腺激素释放激素（TRH，7微克/千克）。TRH给药后血清TSH的平均峰值为16.0±1.1 mU/L（95%置信区间，9.0 - 42.0 mU/L），92%的儿童在TRH给药后30分钟出现峰值。夜间血清TSH绝对峰值与TRH给药后血清TSH峰值显著相关（r = 0.62；P < 0.001），而年龄、性别和青春期状态与夜间TSH增幅或TSH对TRH的反应均无相关性。我们得出结论，正常儿童血清TSH存在昼夜变化，其特征为夜间TSH增幅，且夜间出现的血清TSH峰值与TRH给药后血清TSH峰值水平相关。
