Butt D A, Sochett E B
Division of Endocrinology, Hospital for Sick Children, Toronto, Ontario, Canada.
Clin Endocrinol (Oxf). 1997 Oct;47(4):447-54. doi: 10.1046/j.1365-2265.1997.2821086.x.
The majority of short statured children referred for serum GH testing prove to be GH sufficient. The purpose of our study was to evaluate urinary growth hormone (uGH) as a screening test for GH sufficiency.
We studied (i) short statured children previously diagnosed as GH sufficient (n = 44) or GH deficient (n = 41) (peak serum GH > or = 8 micrograms/l or < 8 micrograms/l, respectively); (ii) short children undergoing serum GH stimulation tests (n = 23, test group); (iii) normal statured children (n = 45, control group).
Three separate overnight urine collections were obtained in all groups. GH injections in GH deficient subjects were discontinued 4 days prior to urine collection.
uGH concentrations were measured using a chemiluminescence immunoassay. Overnight uGH was expressed in several ways (overnight excretion and overnight excretion corrected for body surface area, time and creatinine). Receiver operator curves (ROC) were constructed from the data obtained in the GH sufficient and deficient subjects. Sensitivity and specificity were then determined for various urinary cut-offs. These cutoffs were validated in turn in the test group by comparison of the predicted with the observed GH status.
The GH deficient group had the lowest GH output with respect to overnight uGH, overnight uGH/m2, overnight uGH/h and overnight uGH/creatinine when compared with the GH sufficient and control groups (P = 0.0001). Overnight uGH/m2 data gave the greatest area under the ROC curve. At 100% specificity (no GH deficient subjects), it had the highest sensitivity, 63.6% (49.2-78.0% CI) at a cut-off of 2.3 ng/m2 (63.6% of GH sufficient subjects had uGH levels > 2.3 ng/m2). When this and other cut-offs were applied to the test group, we found consistency between the observed and predicted numbers of GH sufficient and deficient subjects.
We conclude that urinary GH is a useful test for the diagnosis of GH sufficiency as defined by serum criteria and can be used to reduce significantly the number of serum stimulation tests.
大多数因血清生长激素（GH）检测而转诊的身材矮小儿童被证明生长激素充足。我们研究的目的是评估尿生长激素（uGH）作为生长激素充足性的筛查试验。
我们研究了（i）先前被诊断为生长激素充足（n = 44）或生长激素缺乏（n = 41）（血清生长激素峰值分别≥8微克/升或＜8微克/升）的身材矮小儿童；（ii）正在接受血清生长激素刺激试验的矮小儿童（n = 23，试验组）；（iii）身材正常的儿童（n = 45，对照组）。
所有组均进行三次独立的夜间尿液收集。生长激素缺乏受试者在尿液收集前4天停止注射生长激素。
使用化学发光免疫分析法测量uGH浓度。夜间uGH以多种方式表示（夜间排泄量以及经体表面积、时间和肌酐校正的夜间排泄量）。根据生长激素充足和缺乏受试者获得的数据构建受试者工作特征曲线（ROC）。然后确定各种尿界值的敏感性和特异性。通过将预测的生长激素状态与观察到的生长激素状态进行比较，依次在试验组中验证这些界值。
与生长激素充足组和对照组相比，生长激素缺乏组在夜间uGH、夜间uGH/m²、夜间uGH/h和夜间uGH/肌酐方面的生长激素输出最低（P = 0.0001）。夜间uGH/m²数据在ROC曲线下的面积最大。在100%特异性（无生长激素缺乏受试者）时，其敏感性最高，在界值为2.3 ng/m²时为63.6%（95%置信区间49.2 - 78.0%）（63.6%的生长激素充足受试者uGH水平＞2.3 ng/m²）。当将此界值和其他界值应用于试验组时，我们发现观察到的和预测的生长激素充足和缺乏受试者数量之间具有一致性。
我们得出结论，尿生长激素是一种用于诊断符合血清标准定义的生长激素充足性的有用试验，可用于显著减少血清刺激试验的数量。
