Looks like absolute nonsense. Let's say a 60 year old has about a 10% risk of a cardiac episode, this article suggest that an A1C of 5.6 raises it to 25%, of 6.6 to over 60%, and above that you're almost guaranteed to die the next day.
A paper by a proper doctor, Professor Christianssen, given at a copenhagen annual meeting suggested that an A1C in a non-diabetic of 5.5, compared with 4.6, represents a 24% increased risk. What this means, I believe, is that if your normal risk of cardio vascular disease (because of your age, weight etc) would have been 10%, then it would become 12.4% if your A1C went from 4.6 to 5.5. Doesn't sound so bad like that does it?
It's also worth noting that the same study suggested that a normal, non-diabetic person sees an increase in HBA1C with age once over 40 years old. It suggests that it increases by 0.6% from the age of 40 to 70. It also suggested that a normal 70 year old would have an A1C in the region of 6.2%
Malc