An interesting question. Do you think the results are going to be varied? I don't think so.

This article may help

Article Measurement of HbA1c from stored whole blood samples in the ...

Best wishes

Ying-Xian Goh

If you keep it for 72 hrs in -20 C it's value remains unchanged.

Hi Hussain Alsaffar,

Thanks for the answer.

However, if you are referring to the ARIC study, kindly note that they also have another earlier publication [1] that mentioned that the results obtained were "more variable and slightly higher HbA1c". For me, the outcome is kind of contradicting each other. If you could, kindly review it too. I am afraid that it is my interpretation bias.

Apart from that, a study [2] also has shown that fresh samples stored for one year at -80 C have significantly decreased in HbA1c concentration. Furthermore, if you wish to read more, personally, I found this article [3] is quite good.

An additional question of it:

Will degraded hemoglobin affects the HbA1c concentration?

For me, it will not affect much as the glucose will still be bonded to the N-terminal of valine residues, no matter how the hemoglobin Beta chain looks like.

I would like to listen to your opinion too! Many thanks in advance.

GOH

Reference:

[1] Article Stability of haemoglobin A(1c) (HbA(1c)) measurements from f...

[2] Article Glycated hemoglobin (HbA1c) measurement in frozen whole bloo...

[3] Article The influence of sample freezing at -80°C for 2-12 weeks on ...

Dear Goh,

You have nicely reviewed the topic. In the study that you mentioned, you may have noticed that the mean difference in HbA1c between the short and long-term storage (more than a decade!!) was only 0.35%. The authors also have concluded that their results have implications only for research using stored samples.

For clinical decision making and disease categorization, the archived samples are as good as fresh samples.