That requires some parsing...but I think what you're trying to say is that since the way an A1c measures average blood sugar is by measuring the bonding of glucose to hemoglobin, i.e. the glycation of the protein that is hemoglobin, therefore A1c somehow doesn't shed light on blood glucose. If my interpretation of your comment is correct, then you seem to be confused, because 1) it's precisely that protein glycation that allows us to infer average blood glucose levels and 2) A1c *is* one of the accepted diagnostic measures for diabetes, notwithstanding our physician colleague missing the memo on that. Or am I misunderstanding your comment?

I didn't say it doesn't shed light on blood glucose, just that it's not the defining factor of diabetes, it's secondary to a glucose disorder and there are other factors which can cause it to be elevated.

1) It does, but that's also a problem, if I stick my feet in the freezer and head in the oven, on average, my external body temperature is pretty good. Extremes for whatever reason will be recorded in the A1c, this doesn't necessarily make someone a diabetic, may just indicate they were sick/injured in the past.

2) While it is accepted it does have a number of cons and pros which the ADA outline, lab standardisation being one, standardisation with blood glucose is much better, low B12 and other conditions can cause the result to be off/wrong...in a patient with a prediabetes result like the OP here, relying on one test only to label them as 'pre diabetic' when they are a lean/fit patient wouldn't be the best outcome. Medicine isn't always about using blood results to diagnose, you need to look at the patient as well, a lean fit person with a one off elevated A1c should indicate further testing rather than saying they are prediabetic and you need to eat better etc. (I'm not saying a lean fit person can't be type 2 diabetic or type 1, just that out of nowhere, a prediabetic reading in a lean person seems odd and needs a closer look).

Yep, agreed with almost all of that. A diagnosis off any one test is problematic (which the ADA guidelines emphasize), though whether the A1c is more susceptible to this than a one-off blood glucose test is debatable. The averaging issue I find less compelling, hypoglycemia is rare in individuals not on diabetes meds, so an elevated A1c is pretty compelling evidence of elevated BGs, albeit with a few other caveats as you mention. All the ways of screening for/diagnosing diabetes seem problematic in some way; glucose tolerance, preferably with insulin levels also measured, seems to shed the most light (but is also the most hassle from the patient's perspective).

Thanks for engaging constructively!

This has been a very interesting read for this T2D, but I just wanted to throw something else into the mix -

I believe that most (if not all) of the commentators on this thread are male. The OP is not - and being a woman makes a difference. There are other things which influence a tendency to pre- and full-blown diabetes, such as Polycystic Ovarian Syndrome. Insulin resistance (often presenting just like T2D) is one of the first markers for PCOS. (There's an article about it here.)

Shell428, you probably don't have one yet, but it might be worth you getting a referral to an endocrinologist. I love my PCP (she's a triathlete too!), but my endo is the one I couldn't live without. An appointment might do nothing more than set your mind at ease, but that would be worth it to me to rule out the possibility that the pre-d is symptomatic of something more complex. (Not that diabetes is not truly complex to manage in its own right!!)

Either way - it may seem overwhelming but it is something that can be effectively managed. Best wishes.