目的 探讨基础血清促性腺激素(gonadotropin, Gn)值对女童性早熟的诊断作用, 并确定最优界值点。方法 自2012年1月-2013年7月在盛京医院发育儿科确诊为中枢性性早熟(central precocious puberty, CPP)和单纯乳房早发育(premature thelarche, PT)的101例患儿应用化学发光法检测Am 8:00-10:00基础血清促黄体生成素(luteinizing hormone, LH)、卵泡刺激素(follicle stimulating hormone, FSH)水平, 采用受试者工作特征(ROC)曲线分析LH、FSH及LH/FSH曲线下面积、诊断CPP的界值点及所对应的敏感度和特异度。结果 101例患儿 LH、FSH、LH/FSH比值诊断CPP时的ROC曲线下面积分别为0.834、0.742、0.808, 排除4岁以下患儿后的83例, 曲线下面积分别为0.898、0.842、0.854, 排除6岁以下患儿后的60例, 曲线下面积分别为0.895、0.845、0.870;3组曲线LH界值点分别取0.36、0.36、0.38 U/L时, 诊断CPP的敏感度分别为77.6% 、78.7%、75.0%, 特异度分别为81.8%、97.2%、100%;3组曲线FSH界值点分别取2.51、3.63、3.48 U/L时, 诊断CPP的敏感度分别为85.7%、68.1%、69.4%, 特异度分别为57.7%、91.7%、91.7%;3组曲线LH/FSH比值界值点分别取0.09、0.03、0.03时, 诊断CPP敏感度分别为77.6%、85.1%、83.3%, 特异度为75.0%、77.8%、83.3%。结论 基础血清LH在诊断CPP时有较高的特异度, 随着对4岁以下及6岁以下年龄阶段的排除, 诊断CPP的特异度明显增加;4岁以上的女童基础血清LH>0.36 U/L时, 结合临床即可确诊为CPP, 但LH≤0.36 U/L时在各年龄阶段均不能有效排除CPP。

Objective To study the clinical value of basal serum gonadotropin levels in the diagnosis of precocious puberty in girls and determine the optimal cut-off points values. Methods A total of 101 girls with central precocious puberty (CPP) and premature thelarche( PT) were enrolled from Developmental Pediatrics of Shengjing Hospital from January 2012 to July 2013.luteinizing hormone (LH) and follicle stimulating hormone (FSH) were measured by chemiluminescent immunometric assay.The receiver operating characteristic (ROC) curve was used to analyze the area under the ROC curve (AUC) for basal serum LH, FSH, LH/FSH ratio, the cut-off points, the sensitivity and specificity. Results The AUC of LH, FSH, LH/FSH ratios among 101 girls were 0.834, 0.742 and 0.808 respectively.The AUC of 83 girls after excluding the girls less than 4 years were 0.898, 0.842 and 0.854.Without the girls below 6 years, the AUC of 60 girls were 0.895, 0.845 and 0.870, respectively.When LH cut-off points were 0.36 U/L, 0.36 U/L, 0.38 U/L in each group, the sensitivity were 77.6% , 78.7%, 75.0%, and the specificity were 81.8%, 97.2%, 100% respectively.When FSH cut-off points were 2.51 U/L, 3.63 U/L, 3.48 U/L, the sensitivity were 85.7%, 68.1%, 69.4%, and the specificity were 57.7%, 91.7%, 91.7% respectively.When LH/FSH ratio cut-off points were 0.09, 0.03, 0.03, the sensitivity were 77.6%, 85.1%, 83.3%, and the specificity were 75.0%, 77.8%, 83.3% respectively. Conclusions Basal serum LH has a higher specificity for diagnosis of CPP.In addition, the specificity can be elevated gradually when excluding the girls below 4 years and 6 years.When the basal serum LH level is higher than 0.36 U/L, the diagnosis of CPP can be confirmed among the girls over the age of 4 years in combination with clinical manifestation.However, when the basal serum LH is lower than 0.36 U/L, we cannot refute the presence of CPP in girls of any age.