糖化血红蛋白对妊娠糖尿病的筛查和诊断价值研究

目的探讨糖化血红蛋白(HbAlc)对妊娠糖尿病(GDM)的筛查、诊断的价值。方法 932名足月单胎妊娠初产妇女在孕24～28周常规行75 g口服糖耐量试验(OGTT)和HbAlc检测,分别对照HbAlc各个切点的OGTT结果,观察不同HbAlc切点的诊断敏感性和特异性。结果 HbAlc在5.5%的敏感性为92.73%,特异性为51.43%;在6.0%的敏感性为72.73%,特异性为88.14%;在6.5%的敏感性为49.09%,特异性为99.77%。HbAlc超过5.5%后GDM的检出率即明显增加。如果考虑单个切点的诊断价值,HbAlc在6.0%为较适宜的切点。但在强调早期发现、干预孕期轻度高血糖的治疗新理念下,其作为筛查标准的敏感性不够。HbAlc≤5.5%的孕妇GDM风险低,HbAlc≥6.5%的孕妇极可能为GDM。HbAlc在5.5%～6.5%的孕妇为HbAlc受损,其GDM发病风险明显增加,须加强孕期监测和管理。结论选择HbAlc在5.5%和6.5%两个切点,保证筛查的高敏感性和诊断的高特异性,可以更好地识别孕期高血糖。

Diagnostic Value of Glycated Hemoglobin A1c for Gestational Diabetes Mellitus

Objective To investigate the value of glycated hemoglobin A1c(HbA1c) as a screening and diagnosing parameter for gestational diabetes mellitus(GDM).Methods 932 singleton primiparas underwent the one-step 75g oral glucose tolerance test(OGTT) for universal screening of GDM during 24~28 weeks.HbA1c was also assessed in all subjects.Comparing the performance of different cut-offs of HbA1c in identifying GDM,using OGTT results as reference standard.Results HbA1c at 5.5% gave a high sensitivity of 92.73% while a low specificity of 51.43%;HbA1c at 6.0% and 6.5% provided sensitivities of 72.73% and 49.09%,specificities of 88.14% and 99.77%,respectively.The optimal diagnostic cut-off value of HbA1c was 6.0% if a single cut-off point is considered.However,a single cut-off of HbA1c might have limitation as a tool for effective screening of GDM under the new diagnosis criteria.As HbA1c≤ 5.5% and HbA1c≥6.5% may very likely predict the absence and presence of GDM,we recommend using two cut-off values for A1c to achieve high sensitivity for screening and optimal specificity for diagnosis of GDM.Conclusion Women withimpaired HbA1c at 5.5~6.0% have a high risk of GDM and therefore need immediate confirming test,close monitoring and effective management.