HBA1C Diabetes Blood Test

HBA1C Diabetes Blood Test

November 5, 2019 0 By Jose Scott


How do we really look at people’s blood sugars and know what is going on? Well for most people they will do finger prick testing and they might check their blood sugars in the morning or throughout the day and that gives them a clear indication of what their blood sugar is. But the problem with checking your blood sugar is it depends when you do it. And it depends on how often you do it. And it depends on how honest you are when you do it because for example a person might decide that if they have a piece of cake they don’t want to check their blood sugar because it might be bad or the readings might be high and they will feel unhappy about that. So what we need is a way to independently assess glucose control. And the best way to do that is to have a blood test. And the particular test that we use is something called an HbA1c. And I wanted to just explain a little bit about how that test works and so you can understand the implication and the assessment and why it is important to have 4 tests a year. Now what we are measuring is not blood sugar at all. We are measuring the amount of sugar that has attached to red blood cells. And red blood cells in our blood are the molecules and the compounds and the cells that carry oxygen. And it is one of the reasons that our blood is red because it is full of these red cells. And it turns out that sugar will actually bind to one particular type of haemoglobin called the haemoglobin A1. And so it is quite normal for a person whether they have diabetes or they don’t have diabetes to have a certain percentage of their haemoglobin bound up in sugar. But as a percentage it is actually quite a small amount that actually has sugar attached. Now if you have diabetes then your blood sugar is higher and so more of these cells are affected by sugar and more of them end up having glucose attached. So the HbA1c goes up. One of the important aspects about this test is that we know that there is a very strong correlation between an HbA1c and the risk of developing complications. So it is a critical test. The other thing that we know is that every 3 months we make new red blood cells. So the blood in 3 months’ time has only been exposed to the sugar in that previous 3 months. So what you can’t do is you can’t say oh well the last time I had a test was 3 weeks ago or 3 years ago and assume that they both provide you with the same amount of information. Every 3 months we change our blood over and every 3 months there is a different amount of effect of glucose on red blood cells.