Popovic Vera, Pekic Sandra, Micic Dragan, Damjanovic Svetozar, Marikovic Jelena, Simic Mirjana, Dieguez Carlos, Casanueva Felipe F
Institute of Endocrinology, University Clinical Centre, School of Medicine and Complejo Hospitalario de Santiago, Santiago de Compostela University, Spain.
Clin Endocrinol (Oxf). 2004 Feb;60(2):185-91. doi: 10.1046/j.1365-2265.2003.01955.x.
The diagnosis of GH deficiency (GHD) is controversial, relying on GH secretion elicited by the provocative tests of GH reserve. However, the performance of most of the tests in use have not been evaluated rigorously. The repeatability of a test is a prerequisite before evaluating its diagnostic capability.
The combined administration of GH-releasing hormone (GHRH) and GH-releasing hexapeptide (GHRP-6) is an efficacious test of GH reserve in adults, and the target of this work was to evaluate its reproducibility.
Seventeen healthy subjects were challenged with GHRH plus GHRP-6 (1 micro g/kg i.v.). All subjects underwent four tests on different days separated by at least 2 months. GH peaks were evaluated by several mathematical analyses of reproducibility.
As a group, the subjects showed high reproducibility after the four tests, with GH peaks of 46.0 +/- 5.1; 48.4 +/- 6.4; 50.1 +/- 5.4 and 52.9 +/- 5.8 micro g/l, respectively (1 micro g/l = 3 mU/l). Individually analysed, the reproducibility was good, and the regression analysis showed a correlation between tests 1 and 2 of R = 0.729, P < 0.0009, between tests 1 and 3 of R = 0.710, P < 0.001, and between tests 1 and 4 of R = 0.683, P < 0.002. Under mathematical analysis, the multiple correlation coefficient analysis, analysis of variance (anova) with repeated measurements, repeatability index, the simplest coefficient of variation and the intraclass correlation coefficient (ICC) all unambiguously showed that the GHRH + GHRP-6 test was reproducible. Furthermore, the repeated tests did not alter the biochemical diagnosis of the subjects, with absence of false-positive values.
The GHRH + GHRP-6 test of GH reserve is reproducible in adult subjects.
生长激素缺乏症（GHD）的诊断存在争议，依赖于生长激素储备激发试验所诱发的生长激素分泌情况。然而，目前使用的大多数试验的性能尚未得到严格评估。在评估一项试验的诊断能力之前，其重复性是一个前提条件。
生长激素释放激素（GHRH）和生长激素释放六肽（GHRP-6）联合给药是评估成人生长激素储备的有效试验，本研究的目的是评估其可重复性。
17名健康受试者接受GHRH加GHRP-6（1μg/kg静脉注射）激发试验。所有受试者在不同日期进行4次试验，间隔至少2个月。通过几种重复性数学分析方法评估生长激素峰值。
作为一个整体，受试者在4次试验后显示出高度可重复性，生长激素峰值分别为46.0±5.1；48.4±6.4；50.1±5.4和52.9±5.8μg/L（1μg/L = 3mU/L）。单独分析时，可重复性良好，回归分析显示试验1和试验2之间的相关性R = 0.729，P < 0.0009；试验1和试验3之间的相关性R = 0.710，P < 0.001；试验1和试验4之间的相关性R = 0.683，P < 0.002。在数学分析中，多重相关系数分析、重复测量方差分析（anova）、重复性指数、最简单变异系数和组内相关系数（ICC）均明确显示GHRH + GHRP-6试验具有可重复性。此外，重复试验未改变受试者的生化诊断结果，无假阳性值。
GHRH + GHRP-6生长激素储备试验在成年受试者中具有可重复性。
