糖化血红蛋白在糖耐量受损筛查中的价值

目的探讨糖化血红蛋白（HbAlc）在健康体检人群中对糖耐量异常（IGT）的筛查价值。方法对参加健康体检的489名广州户籍汉族人进行口服葡萄糖耐量试验（OG337）和HbAlc检测，以OGTr结果为诊断标准，通过受试者工作特征（ROC）曲线分析分别获得HbAlc和空腹血糖（FPG）单独诊断IGT的ROC曲线下面积（AUC）、最佳临界值、灵敏度约95％的临界值和特异度约95％时的临界值，并计算和比较在上述临界值单独以及HbAlc和FPG不同临界值间两两联合诊断IGT时的各诊断试验评价指标Youden指数（YI）、灵敏度（Sn）、特异度（sp）、阳性预测值（＋PV）、阴性预测值（-PV）、阳性似然比（＋LR）和阴性似然比（～LR）。结果HbAlc、FPG诊断IGT的AUC分别是0．605和0．679，最佳临界值分别是6．05％和5．465mmol／L，此时Y1分别是0．186和0．265、Sn分别是40．3％和56．9％、Sp分别是78．3％和69．6％、＋PV分别是43．6％和43．9％、-PV分别是75．8％和79．5％、＋LR分别是1．853和1．871，-LR分别是0．763和0．619；联合试验最佳组合的YI是0．282，Sn是61．8％，Sp是66.4％，＋PV分别是43．4％，-PV是80．6，＋LR是1．838，-LR是0．575。结论糖化血红蛋白单独、以及联合空腹血糖均不适合在体检人群中筛查糖耐量受损。

Value of blood glycosylated hemoglobin detection in screening patients with impaired glucose tolerance

Objective To explore the value of blood glycosylated hemoglobin detection in identifying patients with impaired glucose tolerance （IGT） from those undergoing health examination. Methods 489 residents in Guangzhou region undergoing health examination suffered an oral glucose tolerance test （OGTT） as well as blood glycosylated hemoglobin （HbAlc） detection. Based on the results of OGTT as diagnostic standards, receiver operating characteristic （ROC） analysis were performed to obtain the Area under the ROC curve （AUC）, the optimal thresholds, the thresholds of having about 95% sensibility and the thresholds of having about 95% specificity when using HbAlc and fasting plasma glucose （FPG） alone as a diagnostic test, respectively. Some indexes, such as youden index （YI）, sensitivity （Sn）, specificity （Sp）, positive predictive value （＋PV）, negative predictive value （-PV）, positive likelihood ratio （＋LR） and negative likelihood ratio （-LR）, were computed when IGT was diagnosed with HbAlc alone, FPG alone and combination tests that one of the three thresholds mefioned above from HbAlc was matched with that from FPG each other, respectively. Results The AUC for HbAlc and FPG to diagnose IGT was 0.605 and 0.679, respectively. At the optimal threshold of 6.05% for HbAlc and 5.465 mmol/L for FPG, YI was 0.186 and 0.265, Sn was 40.3% and 56.9%, Sp was 78.3% and 69.6%, ＋PV was 43.6% and 43.9%, -PV was 75.8% and 79.5%, ＋LR was 1.853 and 1.871, -LR was 0.763 and 0.619, for HbAlc and FPG, respectively. Of the combination tests the best one had a YI of 0.282, a Sn of 61.8% , a Sp of 66.4% , a ＋PV of 43.4% , a -PV of 80.6, a ＋LR of 1.838 and a -LR of 0.575. Conclusion Neither HbAlc alone nor HbAlc combined with FPG is available in screening patients with impaired glucose tolerance among subjects undergoing health examination.