COMPREHENSIVE REVIEW ON HBA1C IN DIAGNOSIS OF DIABETES MELLITUS

Abstract

The prevalence of diabetes in population and type 2 diabetes is particular, has reached epidemic proportions worldwide. The HbA1c test is currently one of the best ways to diagnose diabetes. Measurement of glycated hemoglobin is recommended for both (a) checking blood sugar control in people who might be pre-diabetic and (b) monitoring blood sugar control in patients with more elevated levels, termed diabetes mellitus. Measurement of HbA1c, is an estimation of long-term average glycemia, which assists diabetics as well as their physicians by providing treatment goals to reduce the risks associated with the development and progression of chronic complications of diabetes. Studies have shown that A1c is an index of average blood glucose over the preceding few weeks to months. HbA1c truly does not reflect glycemic control as claimed. There are many factors that cause variation in A1c results. Factors affecting measurement of HbA1c like erythrocyte turnover rate, alcoholism, use of certain drugs in treatment of malignancies, human immunodeficiency virus or hepatitis C virus infection are known provide false results. Hb variants are formed by single base pair mutations in the globin genes of haemoglobin, resulting in an amino acid substitution. There are over 700 silent variants of which most of them interfere with HbA1c. The measurement of HbA1c is usually by HPLC method, but interference of these Hb variants is known to provide false results, hence it is recommended to modify the method to get accurate results.