by Glycated haemoglobin, also known as hemoglobin A1c or HbA1c, is a form of haemoglobin that is formed in a non-enzymatic glycation pathway by attachment of glucose to the N-terminal valine residue of the beta chain of hemoglobin. Haemoglobin is the protein molecule in red blood cells that carries oxygen and normally has a lifespan of about 120 days as red blood cells are recycled naturally. However, when glucose attaches to haemoglobin, it becomes glycated and the lifespan of red blood cells extends to their full natural lifespan of around 120 days. Therefore, the proportion of glycated haemoglobin provides an integrated measure of average blood glucose levels over the preceding 6-8 weeks prior to the test.
Why Is Glycated Haemoglobin Testing Important?
Glycated Haemoglobin Testing provides a reliable measure of long-term glycaemic control in patients with diabetes and prediabetes. It reflects average blood glucose levels over the previous 6-8 weeks, corresponding to the lifespan of red blood cells. Short-term fluctuations in blood glucose levels do not seriously affect HbA1c levels. Therefore, HbA1c testing serves as a better indicator of long-term glycaemic control compared to single random or daily blood glucose measurements which can vary significantly during the day. Precise measurement and monitoring of HbA1c levels helps in optimizing therapy and assessing the risks of diabetes complications in the long run. It also aids in monitoring the effectiveness of treatment regimens and therapeutic lifestyle changes in bringing down glucose levels over time.
How Is Glycated Haemoglobin Test Performed?
There are several standardized laboratory tests that can precisely measure glycated haemoglobin levels. The most common methods used include:
– Immunoassay: These tests use antibodies specifically developed against the glycated portion of haemoglobin to detect and quantify HbA1c levels.
– Ion-exchange HPLC: In this high-performance liquid chromatography method, HbA1c is separated from other types of haemoglobin using an ion-exchange resin and measured.
– Boronate affinity chromatography: This uses affinity chromatography technique to separate HbA1c from non-glycated haemoglobin based on their differential affinity for boronate gel.
– Capillary electrophoresis: It works on the principle of separating HbA1c from other haemoglobin types by their differential electrophoretic mobilities in alkaline buffers.
For any of these laboratory methods, a small blood sample, usually from a finger-prick or blood draw, is sufficient. The test is usually reported as a percentage/fraction of total haemoglobin. It takes 1-2 days to obtain HbA1c test results from an accredited laboratory.
Interpreting Glycated Haemoglobin Test Results
The American Diabetes Association recommends the following cut-off points to define glycaemic control based on HbA1c test results:
– HbA1c <5.7% – Normal, nondiabetic range
– HbA1c 5.7-6.4% – Prediabetes range
– HbA1c ≥6.5% – Diabetes range
– HbA1c <7% – Target for many nonpregnant adults
– HbA1c <6% – Stringent target for selected individual patients
– HbA1c <8% – Target for many pregnant women
– HbA1c ≥9% – Indicating very poor control
Ongoing monitoring and documentation of HbA1c levels every 3-6 months helps healthcare providers optimize therapy and ensure patients are achieving their personalized glycaemic goals. Trend analysis over time also predicts future risks of diabetic complications.
Factors Influencing Glycated Haemoglobin Testing
Some medical conditions and lifestyle factors can potentially interfere with the accuracy of HbA1c test results. These include:
– Haemoglobinopathies: Conditions like sickle cell disease, thalassemia, etc. alter normal haemoglobin production.
– Iron deficiency: Low iron stores seen in anaemia patients affect red blood cell lifespan and heme synthesis.
– Recent blood loss or transfusions: Alters true HbA1c levels.
– Pregnancy: Hormonal changes affect HbA1c levels during pregnancy.
– Liver or kidney disease: Alters red blood cell lifespan.
– Severe hypo- or hyperglycaemia: Fluctuating glucose extremes affect short-term HbA1c levels.
In such cases, alternative tests like frequent self-monitoring of blood glucose may be required along with clinical judgement for glycaemic management. Lifestyle modifications and regular exercise also have a role to play in optimizing diabetes control.
Glycated Haemoglobin Testing provides a reliable and standardized measure of long-term glycaemic control. It aids healthcare providers to optimize diabetes management strategies, guide therapeutic modifications and reduce long-term risks in patients. Regular monitoring and analysis of HbA1c levels helps meet personalized glycaemic goals.
*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
Money Singh is a seasoned content writer with over four years of experience in the market research sector. Her expertise spans various industries, including food and beverages, biotechnology, chemical and materials, defense and aerospace, consumer goods, etc.
