How accurate?

[jbsmomto1]

If A1c is for the past 3 months, can they diagnose someone on the basis that the fasting sugars were 9.7 but the a1c was 0nly 6.2...That would be prediabetes, or diabetes?....This persons sugars get as high as 13 and even 16 but yet dr has no concerns over the numbers since the a1c was low. How accurate are a1c tests?.....She did take a test where she had to drink a bunch of syrup like stuff and they tested her each hr for 3 hrs, her numbers came back higher than normal but again a1c was only 6.2....

I don't know what to tell her, I know nothing about the syrup she had to drink but she says its how they diagnose.

[fgummett]

A1c is effectively an average (mean) of BG over the last 90 days or so (the approximate life of a red blood cell), weighted towards the last 30 days or so. If you have an equal number of high and low readings you can average out to a good A1c.. kinda like having one hand in a bowl of hot water and the other in a bowl of iced water... on average you feel fine.

Sounds like she also had an Oral Glucose Tolerance Test (OGTT) -- the syrup drink -- so far as I understand, that is the "gold standard" in determining how well or badly our bodies react when we ingest a large amount of sugar... in other words "how well is our BG management system working".