Abstract

Diabetes mellitus was known to mankind since antiquity although the name diabetes mellitus was introduced much later. The disease is characterized by elevated blood sugar and estimation of Glycosylated hemoglobin (HbA1c) remains one of the most important and indispensible tool of investigation besides estimation of fasting and post prandiol blood sugar. The glycosylation is the nonenzymetic conjugation of a sugar to amino group of proteins. The authenticity and use of HbA1c in management of diabetes is established by many landmark trials and studies like the Diabetes Control and Complication Trial, (DCCT), UK Prospective Diabetes Study (UKPDS), Standardization of Glycated Hemoglobin testing, National Glycohemoglobin Standardization Programme etc. These studies have developed the methods of HbA1c estimation, the reference range for identification of pre-diabetics and diabetics, and range at which micro and macro-vascular complications occur. If the pitfalls in the estimation of HbA1c is kept in mind its estimation proves a very valuable tool in the management and follow-up of diabetes Mellitus.