Comparative evaluation of three different methods for HbA1c measurement with High-performance liquid chromatography in diabetic patients.

Abstract

Background:The global prevalence of diabetes mellitus is increasing rapidly. Measurement of glycated hemoglobin, predominantly HbA1c, is fundamental to the management of patients with diabetes. HbA1c is used to monitor long-term glycemic control, adjust therapy, assess the quality of diabetes care and predict the risk for the development of complications. While HbA1c is the standard method for long-term glycemic control in diabetic patients, there are different methods for measurement of HbA1c and all laboratories do not use the reference method (high-performance liquid chromatography [HPLC]). The objective of this study is comparison of three different methods with HPLC to find out which method has an acceptable concordance and correlation with the reference method.Materials and Methods:Fifty-eight diabetic patients were assessed in this study. The blood sample of each patient was checked with Diazyme (enzymatic assay), Nycocard (boronate-affinity binding) and Biosystem (micro column chromatography). The values of HbA1c of each method were compared with the Knauer-HPLC results.Results:The means of the differential values between each method and HPLC in the ANOVA test are as follows: M = 1.8, SD = 1.09 for Nycocard-HPLC; M = 1.5, SD = 1.08 for biosystem-HPLC; M = 1.3, SD = 1.2 for Diazyme-HPLC. Pearson's correlation coefficient between HPLC and Nycocard; 0.76, HPLC and Diazyme; 0.75 and between HPLC and Biosystem was 0.68. Linear regression parameters for each method with HPLC were also determined.Conclusion:Diazyme had a better performance and showed a greater concordance with HPLC among others, although it was not an ideal alternative for HPLC.