糖化血红蛋白用于筛查糖尿病的意义

Diagnostic value of glycated haemoglobin (HbA_1 c) detection as a screening test for diabetes mellitus

目的比较并评价空腹血糖(FPG)和糖化血红蛋白(HbA_1c)在筛查DM中的应用价值。方法上海地区研究对象2298名,为明确DM诊断而就诊者和DM高危人群接受DM筛查者,男956名,女1342名,年龄52±13岁,行OGTT并测定HbA_1c;以其工作特征曲线(ROC)评价FPG和HbA_1c在筛查DM中的敏感性和特异性。结果 (1)按照1999年WHO的DM诊断标准,本研究人群糖耐量正常(NGT)、空腹血糖受损(IFG)、糖耐量受损(IGT)、IGT合并IFG和DM者分别为830、110、380、183、795例。其中DM患病率为34.6%。(2)依据ROC判断,与DM状态相关的FPG最佳临界点为6.1mmol/L,敏感性和特异性均为81.5%,曲线下面积为0.899(95%CI 0.885～0.914),阳性似然比4.18,阴性似然比0.23;与DM状态相关的HbA_1c最佳临界点为6.1%,敏感性和特异性均为81.0%,曲线下面积为0.890(95%CI 0.876～0.904),阳性似然比4.26,阴性似然比0.23;如应用FPG≥6.1mmol/L或HbA_1 c≥6.1%筛查DM,敏感性和特异性分别为96.5%和65.2%,阳性似然比2.77,阴性似然比0.05。结论 FPG和HbA_1c在筛查DM中具有相似的价值,二者均有相似的特异性和敏感性以及阳性似然比和阴性似然比。为了最大限度的筛查出DM患者,建议对于6.1mmol/L≤FPG<7.0mmol/L或HbA_1c≥6.1%的患者行OGTT检查以明确有无DM。

Objective To assess the validity of fasting plasma glucose （FPG） and/or glycated haemoglobin （HbA1 c） as screening tests for diabetes mellitus. Methods A total of 2298 subjects （956 male and 1342 female） in Shanghai area were included. All subjects underwent a 75g oral glucose tolerance test （OGTT） and HbA1 c measurement. Receiver operating characteristic curve （ROC curve） analysis was used to examine the sensitivity and specificity of FPG and HbA1 c for detecting diabetes, which was defined as a FPG≥7.0 mmol/L or a post-challenge 2-h plasma glucose≥11. 1 mmol/L. Results 1. Based on 1999 WHO criteria,830 had normal glucose tolerance（NGT）, 110 had impaired fasting glucose（IFG）, 380 had impaired glucose tolerance（IGT）, 183 had IGT and IFG, 795 had diabetes. The prevalence of newly diagnosed diabetes was 34.6% （n=795）. 2. Based on the ROC curve,the optimal cut-point of FPG related to diabetes diagnosed by OGTT was 6.1mmol/L that was associated with a sensitivity and specificity of 81.5 % and 81.0% respectively. The optimal cut-point of HbA1 c related to diabetes diagnosed by OGTT was 6.1% , which was associated with a sensitivity and specificity of 81.0% and 81.0% respectively. The screening model using FPG≥6.1mmol/L or HbAac≥6.1% had sensitivities of 96.5% for detecting undiagnosed diabetes. Conclusions The simultaneous measurement of FPG and HbA1 c might be a more sensitive and specific screening tool for identifying high-risk individuals with diabetes at an early stage.