血清促性腺激素基础值在性早熟女童诊断中的价值

目的：探讨血清促性腺激素基础值在性早熟女童诊断中的价值。方法：以促性腺激素释放激素（GnRH）激发试验结果作为性早熟诊断的金标准，将77例性早熟女童分为中枢性性早熟（CPP，n=45）和单纯性乳房早发育（IPT，n=32）两组，分别比较两组黄体生成素（LH）、卵泡刺激素（FSH）基础值及LH/FSH比值的差异；并采用受试者工作特征（ROC）曲线分析LH、FSH基础值及LH/FSH比值诊断性早熟的准确性。结果：CPP组患儿血清基础LH、FSH水平及LH/FSH比值均高于IPT组（P<0.01）；两组患儿LH基础值与GnRH激发试验中LH峰值存在正相关；LH、FSH和LH/FSH比值诊断CPP的曲线下面积（AUC）进行比较，AUCLH大于AUCFSH和AUCLH/FSH（均P＜0.05），而AUCFSH和AUCLH/FSH之间比较差异无统计学意义。当血清LH基础值为0.62 IU/L时，敏感度为0.778，特异度为0.906，Youden指数最大（0.684）；当切割值为1.5 IU/L时，诊断敏感度下降为0.311，但特异度为1.0。结论：血清LH基础值诊断CPP的价值优于LH/FSH比值及FSH基础值，可用于性早熟女童门诊的初步诊断，但存在一定的误诊和漏诊率；对于LH基础值大于1.5 IU/L的患儿，结合临床表现可明确诊断，无需另行GnRH激发试验。

Value of basal serum gonadotropin levels in the diagnosis of precocious puberty in girls

Objective To study the value of basal serum gonadotropin levels in the diagnosis of precocious puberty(PP) in girls.Methods A total of 77 girls with PP were divided into central PP(CPP)(n=45) and isolated premature thelarche(IPT) groups(n=32) based on the results of gonadotropin releasing hormone(GnRH) stimulation test,which was considered the gold standard for diagnosis of PP.The two groups were compared with respect to basal serum luteinizing hormone(LH) and follicle-stimulating hormone(FSH) levels and LH/FSH ratio.The receiver operating characteristic(ROC) curve was used to analyze the accuracy of basal LH and FSH levels and LH/FSH ratio in the diagnosis of PP.Results The basal serum LH and FSH levels and LH/FSH ratio in the CPP group were significantly higher than in the IPT group(P<0.01).The basal serum LH level was positively correlated with peak LH level in the GnRH stimulation test in both groups.For diagnosis of CPP,the area under the ROC curve(AUC) for basal serum LH level was larger than for basal serum FSH level and LH/FSH ratio(P<0.05),and there was no significant difference in the AUC value between basal serum FSH level and LH/FSH ratio.When the basal serum LH level was 0.62 IU/L,there was a maximum Youden index(0.684),with 77.8% sensitivity and 90.6% specificity.When the basal serum LH level reached 1.5 IU/L,the sensitivity decreased to 31.1%,but with the highest specificity(100%).Conclusions Basal serum LH level is superior to LH/FSH ratio and basal serum FSH level in the diagnosis of CPP,and can be used for preliminary diagnosis of PP in girls in the out-patient department,but there is some misdiagnosis and missed diagnosis.When basal serum LH level is higher than 1.5 IU/L the diagnosis of CPP can be confirmed in combination with clinical manifestation,without the need for an additional GnRH stimulation test.