Thank you for your interest and comments on our study, "Impact of HbA1c criterion on the detection of subjects with increased risk for diabetes among health check-up recipients in Korea" published in Diabetes & Metabolism Journal 2012;36;151-6.
Regarding the standardization of A1c value, we measured A1c by ion-exchange high-performance liquid chromatography using an automated analyzer (Variant II™; Bio-Rad Laboratories, Hercules, CA, USA), which has already been aligned to the Diabetes Control and Complications Trial (DCCT) reference standard and certified by the National Glycohemoglobin Standardization Program [1,2].