hb1ac - x3 month ave reading

[wellwell1212]

This is a technical query really. Was gassing with the wife and was trying to explain the three month average reading that comes with the hb1ac result and failing to remember what the doc told me about it. Can anyone on here explain how it works and how a x3 month average is obtained?

 

[borofergie]

Red blood cells have an average lifespan of about 120 days, which is about 3 months (although this length of time varies from individual to individual).

During those 120 days the glucose in your blood reacts with the hemoglobin in your blood cells, to create glycated hemoglobin (HbA1c). The higher your blood glucose during those 3 months the more HbA1c your blood cells accumulate and the higher your HbA1c test result.

Rather than being a true three month average, some people think that it is biased towards your more recent BG control, something like 70% for the month before the test, 20% for the month before that, and 10% for the month before that.

 

[Caleb Murdock]

I just want to re-state what borofergie said in a way that might make it clearer.

Basically, sugar in your blood sticks to your red blood cells, and the higher your blood sugar levels, the more sugar will stick to the cells. The A1c test measures the amount of sugar sticking to your red blood cells, and it is weighted towards the most recent months rather than the most distant months. So if your diet was bad in the month before your test, your A1c will rise significantly, and your good diet in the previous 2-3 months won't be reflected as much as your bad diet in the final month.

For me, the word "stick" is what clarifies the situation.

A regular meter reading just reveals the amount of free-floating sugar in your blood at that moment (or 10-20 minutes ago, if you are testing on your arm).

 

[Dougie22]

Caleb,

That's basically how I think about it (sticking).