Glycated Haemoglobin- Recent Developments and Review on Non-Glycemic Variables

Abstract

Glycated hemoglobin (HbA1c) is the current tool for monitoring glycemic control once a diagnosis of diabetes is established. Its role in the diagnosis of diabetes has only recently come to attention. In the past, many international organizations have discussed the role of HbA1c in the diagnosis of diabetes and rejected this application as appropriately DCCT-aligned assays were not used or available globally. Considering the high biological variability, the dynamics of glucose, as well as the limitations of blood glucose monitoring technology, at that time, the possibility of obtaining an integrated average glycemia value by the measurement of a single biomarker elicited immense interest and provided a powerful tool in both diabetes research and clinical management. HbA1c testing was soon facilitated by the development of a new analytical methodology that was suitable for use in clinical laboratories. However, a consensus statement in 2007 on assays used to report HbA1c has now further strengthened the case for a change in the diagnosis of diabetes. Using HbA1c as a screening or diagnostic tool has some logistical advantages over traditional glucose testing (either oral glucose tolerance test [OGTT] or fasting plasma glucose [FPG]). Patients can present for a relatively quick test in a non-fasted state at any point of the day, allowing more scope for opportunistic screening. HbA1c assay readings are less prone to recent influences of physical or emotional stress and provide an indication of longer term glycemic control spanning the last 2-3 months. Owing to such logistical advantages there are calls for HbA1c to become the preferred diagnostic tool over glucose tests. Performing the HbA1c test regularly allows the assessment of glycemic control and verification of the efficacy of medication treatment and of education for self-care. It is estimated that 33% to 49% of people with DM2 cannot achieve adequate goals for glucose, blood pressure, or lipid profile control and only 14% reach normal parameters in these measurements.