I've had pre-D levels for at least the past 4 yrs, but inspite of low-carbing have only managed a small reduction in a1c, but at least now it is just below pre-D levels. However, I think that there may be something else going on with me, as I can tolerate glucose but not carbs ! ! ! 75g of glucose will take me to just 6.3mmol/l maximum, with no reactive hypo either, but even 23g or carbs (in food) can easily take me from anywhere between 9 and 13 mmol/l. Don't know if anyone else has experienced this? But the plain fact is, if I keep on eating carbs as normal I will be in double figures at every meal and will easily produce an elevated a1c to diabetic levels. So, its LCHF for the foreseeable future, and anyway, its a very healthy way of eating too.