2型糖尿病HbA_1c筛查值和诊断值的探讨

Investigation of the HbA_1c values in screening and diagnosing type 2 diabetes mellitus

目的评估HbA_1c在筛查和诊断T2DM中的有效性。方法对497例(男361例,女136例)体检FPG≥5.6 mmol/L者行OGTT并测定HbA_1c、血脂、尿酸、血压等代谢指标。结果 (1)应用受试者工作特性曲线(ROC)进行统计分析,与OGTT诊断DM的相关HbA^1c最佳切点为6.3%,敏感性和特异性分别是79.60%和82.20%,曲线下面积(AUC)为0.873(95%CI 0.831～0.916),HbA^1c为6.5%时的敏感性和特异性分别是62.70%和93.50%。(2)按2010年ADA的DM诊断标准,分别按HbA_1c≥6.5%或OGTT标准诊断DM,无论是否去除两组重叠部分,以HbA_1c≥6.5%标准诊断的DM组的HbA_1c水平显著高于以OGTT标准诊断的DM组,而FPG、2hPG均显著低于以OGTT标准诊断的DM组,其余代谢指标如血压、血脂、尿酸等均无统计学差异。结论当HbA-1c≥6.3%时应进一步行OGTT以明确有无DM,而HbA_1c≥6.5%具有较好的特异性可用于诊断DM,与ADA的推荐一致。

Objective To invettigate the T2DM （type 2 diabetes） screening and diagnosing with HbA1 c values. Methods A total of 497 patients with fasting plasma glucoseS5.6 mmol/L （361 men and 136 women）were selected. An oral glucose tolerance test （OGTT） was performed, and HbA1 c,blood lipids, uric acid, and blood pressure were measured. Results Using a receiver operating characteristic curve （ROC curve）, the optimal cut-point of HbA~ c for diagnosis of T2DM was 6.3%, matched to OGTT for diagnosis of diabetes, with a sensitivity and specificity of 79.60% and 82.20% respectively, and area under the curve （AUC） was 0. 873 （95%CI 0. 831-0. 916）. The HbA1c level of 6.5% for diagnosis of diabetes had sensitivity and specificity of 62. 70% and 93.50%, respectively. On the basis of HbA1c≥ 6.5% or OGTT criteria for diagnosis of diabetes mellitus by ADA 2010, the HbA1c group had significantly higher HbA1 c level than did the OGTT group, had significantly lower levels of FPG and 2hPO than did the OGTT group. There were no significant differences in blood lipids, uric acid and blood pressure between two groups. Conclusions When HbA1 c≥6.3 %, an OGTT should be used to confirm the diagnosis of diabetes. A HbA1c cut point of 6.5% has a specificity of 93.50% for diagnosis of diabetes, which is in complete concordance with ADA recommendation.