Our blood contains red blood cells, and these are made of haemoglobin molecules. Glucose in our blood sticks to the haemoglobin to make what is known as ‘glycosylated haemoglobin’ molecules, which are also described as haemoglobin A1C or HbA1C. The higher the levels of glucose that there are in the blood, then the more haemoglobin A1C or HbA1C will be present.
Red blood cells have a life cycle of somewhere between 8 -12 weeks before they are replaced. When we measure our HbA1C it will tell you how what your blood glucose level has averaged over those previous 8-12 weeks. A non-diabetic HbA1C reading is between 3.5-5.5%, whereas in diabetes patients, good blood sugar control is considered about 6.5%.
The HbA1C test is presently one of the best indicators to determine whether or not a diabetic is keeping their diabetes under control. It usually involves the giving of a blood sample that requires analysis by a laboratory. It needs to be remembered that the HbA1C is not the same as the glucose level, as many may confusingly believe. The glucose/HbA1C numbers which are considered good diabetes control are similar at lower levels, and diverge the higher the two readings are. For example, an HbA1c of 7% means the average glucose level was 8mmols/l, and at higher levels, an HbA1c level of 10% means the average glucose level for the previous 10 weeks was 13mmol/l.
If your most recent reading is over 7% and you’re health is generally good, you should aim to achieve a lower level as soon as possible. This assumes you make the appropriate changes required to improve your overall blood sugar control. Your HbA1C level can be a predictor for the likelihood of diabetic complications.
Blood glucose levels can fluctuate at any time, whether its by the minute, by the hour, or by the day. For control by the hour or by the day, you should use your glucose level as the best guide. Because the HbA1C level only changes slowly, (over 8-12 weeks) it is better used as a ‘quality of blood sugar control’ test.
The glucose levels in diabetics can rise more than usual, often dropping after exercise, increasing after food, and again even moreso after sweet food, making it very hard to control.