Joslin update their figures quite regularly so I don't know why they are quoting 21 year old stats.
Joslin's 2007 "normal" numbers are:
Fasting: < 5.5
2 hour post-prandial: < 7.8
Bedtime < 6.7
A1c < 6%
Source:
http://www.joslin.harvard.edu/docs/Pharm_Guideline_Graded.pdf
Also worth noting is this footnote:
"The true goal of care is to bring A1C as close to normal as safely possible. [1C] A goal of < 7% is chosen as a practical level for most patients using medications that may cause hypoglycemia to avoid the risk of that complication. Achieving normal blood glucose is recommended if it can be done practically and safely. [1B]"
The reason for the 6% is that the DCCT study identified 6% as being the upper limit of non-diabetics. The risk curve for complications including heart disease rises sharply after the A1c goes above 6.5 which is why many bodies now recommend that diabetics should target under 6.5.
The bedtime reading is irrelevant for T2s who are not on insulin unless they are taking sulf drugs at very odd times.
I would personally look for under 7.8 at ONE hour, not two. Again, two hour readings are useful for insulin users in terms of corrections but theres no real meaning behind a 2 hour test for a T2 not on insulin and there doesnt seem to be any reason for that advice to be given to non injectors.
Also, it appears from a lot of the more recent studies that its the peaks that do the damage and that this may be far more important than the A1c in judging long term complication risk. A1c is useful when applied to mass populations, but when looking at an individual, the peaks seem to be what counts.
I'd still rather point T2s at the targets in Jennifer's Advice, although they are slightly out of date:
http://diabetesforum.org.uk/jennifers-advice
Hope thats useful.
