HbA1c对糖调节受损和2型糖尿病的诊断价值

摘要：目的：评估糖化血红蛋白（HbA1c）不同cut off值诊断2型糖尿病（T2DM）的效能，初步探讨美国糖尿病协会（ADA）推荐的HbA1c诊断T2DM及T2DM前期标准对中国人的适用性。 方法：招募接受口服葡萄糖耐量（OGTT）试验且试验前未诊治为T2DM的志愿者338例，用高效液相色谱法检测HbA1c；以WHO标准诊断糖调节受损（IGR）、糖耐量正常和T2DM；用受试者工作特征（ROC）曲线分析不同 cut off值HbA1c诊断IGR和T2DM的效能。 结果：HbA1c在诊断T2DM时，ROC曲线下面积（AUC^ROC）为0.954，最佳cut off值为6.0%，敏感性为92.5%，特异性为86.0%；当HbA1c为6.5%时，敏感性为64.8%，特异性为96.7%；当HbA1c为5.6%时，诊断T2DM阴性预测值为100.0%；HbA1c诊断IGR的AUC^ROC为0.653。 结论: HbA1c用于IGR的诊断效能不高;HbA1c诊断T2DM最佳cut off值为6.0%，此界值诊断敏感性较FPG高，但特异性较差；ADA推荐用于T2DM诊断的cut off值6.5%主要考虑到诊断的特异性，该诊断标准适用于中国人群。

Hemoglobin A1c for diagnosis of type 2 diabetes and pre diabetes

Objective To explore the usefulness of HemoglobinA1c(HbA1c) in the diagnosis of type 2 diabetes mellitus(T2DM) and pre-diabetes status.The detection of HbA1c was recommended by American Diabetes Association(ADA).The diagnostic efficiency of HbA1c in Chinese population was investigated in this study.Methods A total of 338 out-patient who had not been diagnosed as T2DM patients were enrolled.All the subjects accepted oral glucose tolerance test(OGTT) while the levels of HbA1c were tested by high-performance liquid chromatography(HPLC).The diagnosis was based on WHO standard for T2DM,impaired glucose regulation(IGR) and normal glucose tolerance.The diagnostic cut off value of T2DM and IGR were established based on receiver operating characteristic(ROC) curve.Results The area under curve(AUC) of ROC curve of T2DM was 0.954.The optimal diagnostic cut off value of HbA1c was 6.0% in which sensitivity was 92.5% and specificity was 86.0% for diagnosis of T2DM.When cut off value of HbA1c was 6.5%,the sensitivity was 64.8% and specificity was 96.7% for diagnosis of T2DM.When HbA1c was 5.6%,negative predictive value for T2DM was 100%.The AUC of ROC curve of IGR was 0.653.Conclusion The usefulness of HbA1c in IGR subjects was not so desirable.The optimal diagnostic cut off value of HBA1c for T2DM was 6.0%.The sensitivity of HbA1c was higher than that of fasting plasma glucose(FPG) for diagnosis of T2DM,but its specificity was low.The cut off value of 6.5% recommended by ADA had a high specific,which could be suited to Chinese population.