Markkanen Helene M, Pekkarinen Tuula, Hämäläinen Esa, Välimäki Matti J, Alfthan Henrik, Stenman Ulf-Håkan
Helsinki University Central Hospital, HUSLAB, Helsinki, Finland.
HUS Abdominal Centre, Endocrinology, Helsinki University Hospital, Helsinki, Finland.
Growth Horm IGF Res. 2017 Aug;35:52-56. doi: 10.1016/j.ghir.2017.07.002. Epub 2017 Jul 18.
Data on the effect of gender on the interpretation of the GHRH plus arginine stimulation test (GHRH+ARG test) is controversial. We validated the GHRH+ARG stimulation test in control subjects and patients with organic or idiopathic pituitary disease and a suspicion of adult growth hormone deficiency (AGHD) using the Immulite 2000 XPi GH assay.
We studied 126 apparently healthy adults (median age 38.8years) and 34 patients with a suspicion of AGHD (median age 42.2years). Identification of AGHD with the GHRH+ARG test was investigated with commonly accepted BMI-related consensus cut-off limits for peak GH concentrations. Serum samples collected during the GHRH+ARG test were analysed for GH in 2014-2015. Serum IGF-1 concentrations were studied as a reference.
In 14 of 65 (22%) control males the GH peak value was below the BMI-related cut-off limits for GH sufficiency indicating a false diagnosis of AGHD. All control females had a normal GHRH+ARG response. Median peak GH response was significantly (p<0.001) higher in female (39.3μg/L) than in male controls (21μg/L). According to consensus cut-offs all but one young female patient had a deficient response compatible with a diagnosis of AGHD.
The GH response to stimulation by GHRH+ARG is gender-dependent, being lower in healthy males than in females. Gender should be considered when defining cut-off limits for peak GH concentrations in the GHRH+ARG test. The presently used BMI-related cut-off levels will lead to a significant misclassification of males as GH deficient.
关于性别对生长激素释放激素加精氨酸刺激试验（GHRH+ARG试验）结果解读的影响，相关数据存在争议。我们使用免疫发光分析仪Immulite 2000 XPi检测生长激素（GH），对健康对照者、患有器质性或特发性垂体疾病且疑似成人生长激素缺乏症（AGHD）的患者进行了GHRH+ARG刺激试验的验证。
我们研究了126名表面健康的成年人（中位年龄38.8岁）和34名疑似AGHD的患者（中位年龄42.2岁）。采用普遍认可的与体重指数（BMI）相关的GH峰值浓度共识临界值，研究通过GHRH+ARG试验诊断AGHD的情况。在2014年至2015年期间，对GHRH+ARG试验期间采集的血清样本进行GH分析。研究血清胰岛素样生长因子-1（IGF-1）浓度作为参考。
65名对照男性中有14名（22%）的GH峰值低于与BMI相关的GH充足临界值，提示AGHD的误诊。所有对照女性的GHRH+ARG反应均正常。女性的中位GH峰值反应（39.3μg/L）显著高于男性对照（21μg/L）（p<0.001）。根据共识临界值，除一名年轻女性患者外，所有患者的反应均不足，符合AGHD的诊断。
GHRH+ARG刺激引起的GH反应存在性别差异，健康男性低于女性。在确定GHRH+ARG试验中GH峰值浓度的临界值时应考虑性别因素。目前使用的与BMI相关的临界水平将导致大量男性被误分类为GH缺乏。
