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Question to Dexcom G6 users about estimated HbA1c.

E

ElenaP

Well-Known Member
Messages
534
Type of diabetes
Type 1
Treatment type
Pump
My estimated HbA1c on G6 gives me better readings than the HbA1c from blood tests.
My latest HbA1c was 55mmol/mol whereas G6 estimation was 49. This has been the pattern ever since I started to use Dexcom, some 17 months ago.

Does this happen to other people?
 
I assume from reading other threads that this is because all CGMs read interstitial blood and will generally read lower whereas your actual blood tests are venous and more accurate.
Similarly your CGM readings will usually be a couple of points lower than a finger prick reading.
Someone with more knowledge will correct me if I have given you duff information
 
Dexcom g6 doesn't give an estimated HbA1c. It gives what they (and others) have termed GMI. Yes, it's meant to be an estimated A1c but it's not: it could be higher or it could be lower and that's why they changed the term they use. Mine is generally within 0.5 but if it wasn't I wouldn't be surprised

See: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6196826/
 
plantae said:
Mine is generally within 0.5 but if it wasn't I wouldn't be surprised
Click to expand...
I would be content with such a small difference. I am surprised if Dexcom have not calculated allowances for interstitial fluid / blood in their algorithm.
 
For what its worth, my Dexcom (was G6 now G7) seems to consistently give a higher GMI than actual HbA1c results.
 
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