What is "pre-diabetic"?

I said in my first post that I was going to talk later about what a "pre-diabetic" diagnosis means, and how it relates to full-blown diabetes.

Diabetes is diagnosed by blood glucose levels -- either a fasting level of 126 mg/dL, or a level over 200 mg/dL at 2 hours on an oral glucose tolerance test, or a level over 200mg/dL at a post-meal testing plus diabetic symptoms. Fasting BG in the 100-125 range or tolerance-test or post-meal levels in the 140-199 range are considered impaired, or pre-diabetic.

The problem with this is that diabetes is a disease that's diagnosed by its symptoms, not its causes, and what's more, by the severity of its symptoms. It's as if you came to your doctor with a sore throat and a fever, and were told that because your throat pain was only about a 3 on a 1-10 scale, and your fever was only 101.5, you only had pre-strep, and should just take painkillers and fluids until you got to the point where your pain was more than a 6 and/or your fever went over 102, at which point you could come back and they'd give you antibiotics for your full-blown strep throat. Everybody can see that that's ridiculous. But diabetes is known to have genetic causes that degrade performance of the beta cells in the pancreas which produce insulin, and it's known that BG levels over 140mg/dL start doing damage to the beta cells which further degrades their performance, and it's axiomatic that eating higher levels of carbs raises blood sugar in persons with impaired response (that's what "impaired response" means), so the common advice to pre-diabetics, which includes chiefly scolding them about their weight (even though it's usually a symptom of the blood-sugar problem, not a cause) and exercise habits, and coaching them to lose weight by eating less fat, which virtually guarantees that they'll eat more carbs, and that those carbs will continue pushing their blood glucose levels up and damaging their beta cells, means that pre-diabetes will almost inevitably progress to diabetes.

In pre-diabetes, all the factors that produce an official diagnosis of diabetes are there: the genetic causes are there already, and the impaired response, which is itself a symptom, is also there, even though it's not severe yet. If a person continues applying the aggravating factor, though, by eating enough carbs to raise blood glucose to damaging levels, it will progress, blood glucose levels will rise, and symptoms of damage will appear. Therefore, it doesn't make any sense to treat this as a separate condition: if a person with pre-diabetes doesn't behave as if they were a diabetic already, and get their blood sugar down, they will be one eventually.

And that's why, even though the highest blood glucose levels I've seen are only in the 190s, my response to being offered high-carb treats is and will be, "No, thanks. I'm diabetic; I can't eat that."