Impaired Fasting Glucose Question (and general frustrated rant)

My last official NHS fasting glucose blood test came back at 6.2, so I guess I'm now officially in the prediabetic camp (except that my home-tested, 2-hour post-meal numbers are still golden, usually under 6.0). But it got me wondering: is it possible to have severe impaired fasting glucose that gets so bad (i.e. over 7.0) that one would qualify as diabetic by the medical community's standards but still have 'normal' post-meal numbers? If so, how would that be treated if at all?

In relation to my own numbers, I'm not sure what I can do do change them. I'm already a normal weight (although my thyroid's been playing up so I've actually gained about 7 lbs in the last year; BMI went from 20 to 23), I run three times a week and take at least a half hour walk on the others and my carb intake is usually somewhere around 150g / day, so not excessive by most standards. I keep my pasta and rice portions to 40g dry weight every time and don't tend to eat much bread (couple of slices a week). Potatoes are usually (although not always) new and no more than 100g-worth each time.

I really don't want to go ultra-low carb but reckon I could go down to between 100-120g per day. No lower than that otherwise yogurt has to go and that's a no-no!

Sigh. Either I'm carrying around a hell of a lot of visceral fat or something's going horribly wrong

Thanks for answers and advice.

Jo