I’m 33, and my A1c has consistently been about .5% lower than my average bg would predict it to be.
This used to bother me because I worried there might be something wrong that is making my red blood cells die off. My doctor ran a CBC and a few other tests, and everything came back fine. Since my average bg and standard deviation are in good shape, my doctor said I should stop worrying about the discrepancy.
It would still be nice to have an explanation because studies have shown that glycation is the primary cause of complications. Since the A1c is a measurement of glycation, I do think it is important tool.
We discussed this topic quite a bit in this thread: