--i do know that a lot of doctors, even endocrinologists, tend to make their "pre-diabetes" and "diabetes" designations based almost exclusively on blood sugar lab results, without looking at progression as more of a process.

Part of the problem with this is, over time, the lab levels generally considered "pre-diabetic" and "diabetic" have shifted downward to lower numbers, in much the same way as healthy levels of cholesterol have been redefined. I would be more sanguine about this if I felt that these numbers are adjusted as a result of meta-analysis of the best available research, but I am well aware that large pharmacuetical concerns often have an influence over "condition definition" in order that more demand for certain medications is generated. And I know that the ranges are not generally adjusted for age or gender--there is certainly evidence of "normative" blood sugar level rise as people get older, and using the same definitional levels for people much younger may get older people defined as diabetic/pre-diabetic when perhaps they should not be.

I can even see this on my lab results going back twenty years (I keep copies of everything). In the early 2000's, a normal 12-hour fasting blood glucose level range was 65-109; 110-126 was defined as "pre-diabetic" and over 126 as frankly diabetic. Now, the normal fasting blood glucose level has been truncated to 65-99, with 100-126 being pre-diabetic. I have also now started to see frank diabetes classified as anything above 120 for some labs. Similarly with hemoglobin A1C readings; labs I have from years ago list anything below 6 as normal, with 6.1-7 being "impaired" and above 7 diabetic. Now most labs list 5.7-6.4 as "impaired" and 6.5 or greater as frankly diabetic. So I have progressed from "normal" to "impaired" over the years (I've been running 5.7-5.9 mostly for a decade or more) merely due to lab range changes (not that I don't want to get the numbers down more, but that's been getting tougher as I age).

It remains to be seen if more labs will start to go with age adjusted numbers. This is done with certain lab tests, and is being discussed for others (such as TSH/thryoid hormone levels).