Objective

To evaluate the variability of growth hormone stimulation tests results and factors affecting it in short children suspected of having growth hormone deficiency.

Design

The cohort included patients with short stature suspected of having growth hormone deficiency, and who underwent a second stimulation test, after the first stimulation test was positive. Testing was done at a single center from May 2014 to October 2017. Patients' weight, height, age, sex, stimulating agents and test results were recorded.

Results

The study population comprised 200 patients, 108 males and 92 females, average age 9.2 years (2.2–16.6 years). The average peak growth hormone was 5.2 μg/L and 7.8 μg/L in the first and second tests respectively and the concordance rate was 56.5%. The probability of a second positive test was increased if the peak growth hormone level in the first test was below 5 μg/L.

In the second test, Clonidine and Glucagon led to higher peak growth levels than Arginine with averages of 9.02, 9.97 and 6.88 μg/L respectively. Younger children and children with higher BMI SDS only had lower peaks of growth hormone in the second test. The effect of height SDS on peak growth hormone levels was equivocal.

Conclusion

The reproducibility rate of GH simulation tests in our study was low.

A few factors may affect the peak levels of growth hormone in the second test, the most prominent being the peak of growth hormone in the first test.

中文翻译：

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生长激素刺激试验的试验间变异性和影响这种变异性的因素

客观的

评估怀疑有生长激素缺乏症的矮小儿童生长激素刺激试验结果的变异性和影响它的因素。

设计

该队列包括疑似患有生长激素缺乏症的身材矮小患者，他们在第一次刺激试验呈阳性后接受了第二次刺激试验。2014 年 5 月至 2017 年 10 月在单一中心进行测试。记录患者的体重、身高、年龄、性别、刺激剂和测试结果。

结果

研究人群包括 200 名患者，其中男性 108 名，女性 92 名，平均年龄 9.2 岁（2.2-16.6 岁）。第一次和第二次测试的平均峰值生长激素分别为5.2 μg/L和7.8 μg/L，符合率为56.5%。如果第一次测试的峰值生长激素水平低于 5 μg/L，则第二次测试呈阳性的可能性会增加。

在第二个测试中，可乐定和胰高血糖素导致比精氨酸更高的峰值生长水平，平均值分别为 9.02、9.97 和 6.88 μg/L。在第二次测试中，年龄较小的儿童和 BMI SDS 较高的儿童只有较低的生长激素峰值。身高 SDS 对生长激素峰值水平的影响是模棱两可的。

结论

我们研究中GH模拟试验的重复率较低。

一些因素可能会影响第二次测试中生长激素的峰值水平，最突出的是第一次测试中的生长激素峰值。