HbA1c - Diabetes Test

What is HbA1c?

Haemoglobin is the protein material within red blood cells that transports oxygen around the body, delivering it to cells. Sugar molecules, also known as glucose molecules, in the blood bind to the haemoglobin molecules. The haemoglobin is now termed glycosylated haemoglobin, also called haemoglobin A1c, or HbA1c. As your blood glucose level becomes higher, more of the haemoglobin is glycosylated. The glucose and haemoglobin remain attached for about 2-3 months, which is the life span of the red blood cell.

Why is HbA1c important?

HbA1c is used to measure blood glucose levels, and HbA1c levels are used to monitor a person's health. Routine checks can help to maintain health are prevent complications.

High glucose levels (hyperglycaemia) in the blood over a long time period can damage the blood vessels. This can lead to high blood pressure, impaired blood circulation, and the transport of substances between blood and tissues. Diabetes is a serious condition occurring when the blood glucose level is continually too high. Over time, people with too much glucose in the blood develop health complications, such as heart disease and stroke, eye problems, kidney disease, and nerve damage.

On the other hand, too low levels of blood glucose levels (hypoglycaemia) can lead to problems such as shakiness, tiredness, sweating, and confusion. Hypoglycaemia may arise from too little food, an adrenal gland disorder, and some medications including too much diabetes medication (insulin).

Testing at The Online Clinic

The test for HbA1c at The Online Clinic is very easy to use. The collection kit comprises a set of lancets used to extract blood from your finger and collect in a small container. Only 600 mcl of blood is required - a very small quantity. Results are available on the same day as the sample arrives at the laboratory and are delivered online with an interpretation from a doctor.

Who should monitor their HbA1c?

As part of a routine health check, all individuals should have their blood glucose levels checked, usually every 3-6 months. However, the frequency may change if you have certain conditions, are ill, take certain medicines, your treatment is altered, or you are pregnant or planning pregnancy. It is particularly important to measure blood sugar levels if you cannot maintain your blood glucose level within the normal range, if you are at risk of diabetes, or have diabetes.

How to test for HbA1c?

A blood test called the glycosylated hemoglobin or HbA1c test is used to measure the glycosylated haemoglobin level in the blood. The test indicates the average blood glucose level over the past 2 to 3 months, and is usually carried out every 3-6 months. The Online Clinic requires a tiny amount of blood from your finger for analysis at our partner laboratory.

There are other tests to monitor blood glucose, including the finger-prick test that uses a blood-testing meter to measure the blood glucose level in a drop of blood at the time it is taken. These tests are done a few times each day, and are for people living with diabetes.

What are HbA1c target levels?

Blood glucose levels vary between people, time of day, and whether they are taken before or after food. The standard measurement for reporting the HbA1C test result is millimoles per litre (mmol/l) but the older measure of percentage may also be given. The higher the reading, the higher the blood glucose level.

As a general rule:

• Healthy individuals have blood glucose levels of below 5.5 mmol/l before food and below 7.8 mmol/l when taken 2 hours after eating.
• For those with prediabetes, blood glucose levels range 5.5-6.9 mmol/l before food and below 7.8-11.0 mmol/l when taken 2 hours after eating.
• For those with diabetes, blood glucose levels range 7.0 mmol/l or higher before food and 11.1 mmol/l or higher when taken 2 hours after eating; their target ranges are 4.0-7.0 mmol/l before food and below 8.5-9.0 mmol/l when taken after eating.

How to maintain or achieve good HbA1c levels

Healthcare professionals will set you an individual target blood glucose level depending on your health condition. They will advise you on how to maintain your target level if you are within the normal range or discuss lifestyle changes (e.g. a balanced healthy diet, weight loss, and exercise) that help to lower your blood glucose levels and therefore your risk of developing complications.

Reviewed by: Dr Loraine Haslam MBBS, DRCOG, DFSRH, LoC SDI, LoC IUT, MRCGP
GMC registration number: 4524038
Date: 16 August 2022
Next review: 15 August 2024
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