黄体生成素基础值对不同体质量指数女童中枢性性早熟的诊断价值

The diagnostic value of the basal luteinizing hormone level for girls with central precocious puberty based on body mass index

目的:探讨黄体生成素(LH)基础值对不同体质量指数(BMI)女童中枢性性早熟(CPP)的诊断价值及相应界值点。方法:选取2014年1月至2018年12月在福建医科大学附属福州儿童医院内分泌遗传代谢科就诊的6~8岁出现乳房发育的女童1087例,就诊时乳房为Tanner B2或B3期,并根据年龄-性别对应的BMI百分位数分为正常体质量组(840例)、超重组(133例)及肥胖组(114例)。患儿均行促性腺激素释放激素(GnRH)激发试验等检测。采用SPSS 18.0软件对数据进行统计分析,并绘制受试者工作特征曲线(ROC)。结果:正常体质量女童GnRH激发阳性组393例,阴性组447例;超重女童GnRH激发阳性组72例,阴性组61例;肥胖女童GnRH激发阳性组40例,阴性组74例。正常体质量、超重、肥胖女童用于诊断CPP的LH基础值的ROC曲线下面积(AUC)分别为0.826、0.774、0.801,约登指数最大时LH基础值的界值分别为0.245 IU/L、0.225 IU/L、0.145 IU/L,敏感度分别为63.9%、65.3%、80.0%,特异度分别为87.9%、82.0%、71.6%;LH基础值的界值分别为0.455 IU/L、0.480 IU/L、0.335 IU/L时,特异度均达96.6%以上。结论:LH基础值用于不同BMI女童CPP的诊断均具有良好的应用价值,其中肥胖女童CPP诊断界值点最低。

Objective To investigate the diagnostic value and cutoff value of the basal luteinizing hormone(LH)level for central precocious puberty(CPP)in girls with different body mass index(BMI)values.Methods A total of 1087 girls aged 6 to 8 years old with breast development and visiting the Department of Endocrine Genetics and Metabolism,Fuzhou Children′s Hospital of Fujian Medical University from January 2014 to December 2018 were enrolled.The girls had the breast development of Tanner stage B2 or B3.They were divided into groups of normal weight(840 cases),overweight(133 cases)and obesity(114 cases)according to BMI percentiles corresponding to their age and sex.All individuals underwent gonadotropin-releasing hormone(GnRH)agonist test.Statistical analysis was performed using SPSS 18.0 software,and the receiver operating characteristic(ROC)curve was drawn.Results In the normal weight group,393 girls were positive and 447 girls were negative for GnRH test.In the overweight group,72 girls were positive and 61 girls were negative for GnRH test.In the obesity group,40 girls were positive and 74 girls were negative for GnRH test.The areas under the ROC curve(AUC)of the basal LH level for the diagnosis of CPP in the normal weight,overweight,and obese girls were 0.826,0.774,and 0.801,respectively.When the Youden index was maximum,the cutoff values of the basal LH level were 0.245 IU/L,0.225 IU/L and 0.145 IU/L,respectively;the sensitivities were 63.9%,65.3%,and 80.0%,respectively;the specificities were 87.9%,82.0%,and 71.6%,respectively.When the cutoff value of the basal LH level was 0.455 IU/L in the normal weight group,0.480 IU/L in the overweight group,and 0.335 IU/L in the obesity group,the specificities of the 3 groups were all above 96.6%.Conclusions It is reliable to use the basal LH level for CPP diagnosis for girls with different BMI values.The cutoff value of the basal LH level for CPP diagnosis in obese girls is the lowest.