Assessment of HbA1c as a diagnostic tool in diabetes and prediabetes

To evaluate HbA1c as a diagnostic tool in prediabetes-impaired fasting glucose (IFG) and impaired glucose tolerance (IGT), and newly detected diabetes (NDD), defined by plasma glucose and OGTT. 2,231 subjects, of mean age 50.3?±?13.9?years and mean BMI 29.5?±?6.2?kg/m(2), underwent an OGTT. HbA1c performance was assessed using the area under the receiver operating characteristics curve (AUC-ROC). HbA1c was significantly higher in all groups with altered glucose tolerance-5.72?±?0.61% in IFG, 5.84?±?0.63% in IGT, and 7.5?±?1.69% in NDD when compared to normal glucose tolerance-5.23?±?0.65% (P?