Bussières L, Souberbielle J C, Pinto G, Adan L, Noel M, Brauner R
Department of Physiology, Hôpital Necker-Enfants Malades, Université R Descartes, Paris, France.
Clin Endocrinol (Oxf). 2000 Jun;52(6):735-9. doi: 10.1046/j.1365-2265.2000.00999.x.
This study was done to determine whether the use of reference values obtained in children with idiopathic short stature (ISS) improved the clinical value of serum insulin-like growth factor I (IGF-1) as a tool for diagnosing GH deficiency (GHD) in prepubertal children.
Serum IGF-1 was measured with a new IRMA kit (IGFI-RIA CT, Cis Bio, Gif sur Yvette, France) in 168 prepubertal normal children and in prepubertal children with ISS (n = 68), organic GHD due to a craniopharyngioma (oGHD, n = 15) and permanent idiopathic GHD (iGHD, n = 28).
IGF-1 was lower (P < 0.001) in iGHD than in either ISS or oGHD and was below the fifth percentile of the normal range in 29/68 ISS (43%), 8/15 oGHD (53%) and 28/28 (100%) iGHD patients. Three oGHD (20%) and two iGHD (7%) patients had a serum IGF-1 below the fifth percentile of the normal group but above the fifth percentile of the ISS group. Thus, a serum IGF-1 below the fifth percentile of the normal group distinguished between normal children and iGHD with 100% sensitivity, between normal and oGHD with 53% sensitivity and between normal and all GHD (idiopathic + organic) with 84% sensitivity; the overall specificity was only 57%. Conversely, a serum IGF-1 below the fifth percentile of the ISS population distinguished between ISS and iGHD with 93% sensitivity, between ISS and oGHD with 33% sensitivity and between ISS and all GHD with 72% sensitivity; the overall specificity was then 95%.
A serum IGF-1 within the normal range virtually excludes idiopathic GHD but does not rule out organic GHD, whereas an IGF-1 below the ISS range is strongly in favour of GHD, after exclusion of poor nutritional status and/or liver disease. An IGF-1 below the normal range but in the idiopathic short stature range gives no definitive conclusion even when it is associated with a low GH peak. Thus, whereas reference values obtained in normal children must be used to interpret serum IGF-1 in short prepubertal children, reference data obtained in idiopathic short stature children should also be taken into account.
本研究旨在确定使用特发性身材矮小（ISS）儿童获得的参考值是否能提高血清胰岛素样生长因子I（IGF-1）作为诊断青春期前儿童生长激素缺乏症（GHD）工具的临床价值。
使用一种新的免疫放射分析试剂盒（IGFI-RIA CT，Cis Bio，法国伊夫特河畔吉夫）对168名青春期前正常儿童、68名青春期前ISS儿童、15名因颅咽管瘤导致的器质性GHD（oGHD）儿童和28名永久性特发性GHD（iGHD）儿童进行血清IGF-1检测。
iGHD患者的IGF-1水平低于ISS或oGHD患者（P<0.001），29/68例（43%）ISS儿童、8/15例（53%）oGHD儿童和28/28例（100%）iGHD患者的IGF-1水平低于正常范围的第五百分位数。3例（20%）oGHD患者和2例（7%）iGHD患者的血清IGF-1低于正常组的第五百分位数，但高于ISS组的第五百分位数。因此，血清IGF-1低于正常组的第五百分位数对正常儿童和iGHD的鉴别敏感性为100%，对正常和oGHD的鉴别敏感性为53%，对正常和所有GHD（特发性+器质性）的鉴别敏感性为84%；总体特异性仅为57%。相反，血清IGF-1低于ISS人群的第五百分位数对ISS和iGHD的鉴别敏感性为93%，对ISS和oGHD的鉴别敏感性为33%，对ISS和所有GHD的鉴别敏感性为72%；此时总体特异性为95%。
血清IGF-1在正常范围内实际上可排除特发性GHD，但不能排除器质性GHD，而在排除营养状况差和/或肝脏疾病后，IGF-1低于ISS范围强烈提示GHD。即使与低生长激素峰值相关，IGF-1低于正常范围但在特发性身材矮小范围内也不能得出明确结论。因此，虽然必须使用正常儿童获得的参考值来解释青春期前矮小儿童的血清IGF-1，但也应考虑特发性身材矮小儿童获得的参考数据。
