HbA1c (Glycated Haemoglobin)
What is HbA1c?
HbA1c, also known as haemoglobin A1c, is haemoglobin with glucose that has attached itself in the blood cell. HbA1c evaluates the average amount of glucose in the blood over the last two to three months.
Haemoglobin is the protein that transports oxygen within red blood cells. There are several different types of haemoglobin in which the predominant form (approximately 95-98%) is haemoglobin A. The glucose that circulates in the blood binds to the haemoglobin A, and thereby forms HbA1c.
The higher the level of glucose is in the blood, the more HbA1c is formed. As haemoglobins lifespan is around 120 days, HbA1c survives the same amount of time. HbA1c is created on a daily basis and slowly degrades as the older red blood cells dies and the young red cells take their place.
Why do we analyse HbA1c?
An HbA1c test can be used to screen for and diagnose diabetes or even define the risk profile of developing diabetes. This test is also used to monitor a treatment for someone who has been diagnosed with diabetes. Therefore it helps to evaluate a person's glucose level over time.
European Association for the Study of Diabetes (EASD) recommends that the management of glucose levels in type 2 diabetes should be more patient-centred. It is recommended to cooperate with your health care provider to select a goal that reflects each person's individual health status and balance risks and benefits.
HbA1c can be used to monitor glucose levels in diabetics over time. The goal of those with diabetes is to keep their blood sugar levels as close to normal as possible. This helps to minimize the complications caused by chronically elevated glucose levels, such as progressive damage to body organs like kidneys, eyes, cardiovascular system, and nerves. HbA1c test results give a picture of the average amount of glucose in the blood over the last 2-3 months. This can help diabetics and their caregivers know about the measures taken to control their diabetes are successful or need to be adjusted.
HbA1c is often used to help newly diagnosed diabetics determine how elevated their uncontrolled blood sugar levels have been over the past 2-3 months.
HbA1c can be ordered as part of a health check or when someone is suspected of having diabetes because of the classic signs and symptoms of elevated blood glucose levels, such as:
- Increased thirst and drink fluids
- Increased urination
- Increased appetite
- Blurred vision
- Slow-healing infections
HbA1c test can also be justified in overweight patients with the following risk factors:
- Physical inactivity
- First-degree relative (sibling or parent) with diabetes
- High blood pressure (hypertension)
- Abnormal lipid profile (low HDL cholesterol and / or high triglycerides)
- Women with polycystic ovary syndrome
- History of cardiovascular disease
- Other clinical conditions associated with insulin resistance
What does the test result for HbA1c mean?
If you have diabetes and your HbA1c is below the target of 48 mmol/mol it is likely that your diabetes is well controlled. If your HbA1c rises above 48 mmol/mol, you are at increased risk of developing long term complications such as eye disease, kidney disease or nerve damage. It is worth noting that some people can find it difficult to get their HbA1c down to 48 mmol/mol without experiencing frequent episodes of hypoglycaemia (low blood sugar), and if this is the case, the target HbA1c may be higher than 48 mmol/mol.