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

Objective To invettigate the T2DM(type 2 diabetes) screening and diagnosing with HbA_(1c) values.Methods A total of 497 patients with fasting plasma glucose≥5.6 mmol/L(361 men and 136 women) were selected.An oral glucose tolerance test(OGTT) was performed,and HbA_(1c) blood lipids,uric acid,and blood pressure were measured.Results Using a receiver operating characteristic curve(ROC curve),the optimal cut-point of HbA_(1c) 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 HbA_(lC) level of 6.5%for diagnosis of diabetes had sensitivity and specificity of 62.70%and 93.50%,respectively.On the basis of HbA_(1C)≥6.5%or OGTT criteria for diagnosis of diabetes mellitus by ADA 2010,the HbAic group had significantly higher HbA_(1c) level than did the OGTT group,had significantly lower levels of FPG and 2hPG than did the OGTT group.There were no significant differences in blood lipids,uric acid and blood pressure between two groups.Conclusions When HbA_(1c)≥6.3%,an OGTT should be used to confirm the diagnosis of diabetes.A HbA_(1c) cut point of 6.5%has a specificity of 93.50%for diagnosis of diabetes,which is in complete concordance with ADA recommendation.