Measuring HbA1c in the blood is used to reflect average blood-sugar levels over a period of three months in people with Type 1 Diabetes.
When you check your blood glucose level you are measuring how many molecules (or mmol) of glucose are in your blood stream at the time
of monitoring. However, your HbA1c result looks at your overall blood glucose control for the preceding two to three months. Glucose in your bloodstream will attach itself to the haemoglobin part of your red blood cell. If there is a lot of glucose in your blood-stream, this will result in a higher number of haemoglobin with glucose attached. The haemoglobin with attached glucose is referred to as HbA1c or glycated haemoglobin. As your blood cells, and therefore your haemoglobin, live for around 120 days, the HbA1c test gives you an idea of how your blood glucose levels have been tracking over the same time period.
Ideally, you should aim to keep your HbA1c as close to 7% or (53 mmol/ mol) as possible, as long as this can be achieved without significant episodes of hypoglycaemia.
Research has shown that keeping your HbA1c near this can significantly reduce your risk of developing the long- term complications.