She probably meant Hb A1c. Where 42 equates to 6.0%. that's about equivqalent of an overall avrerage of 6.9mmol/l blood glucose reading over the last 3 months.
It is a little tighter than it used to be. They've finally realised that HbA1cs of 6.5% and over are too high to protect people from complications. Non-diabetics have HbA1cs around 4.5 -5% some are lower still. Bernstein says that most non-diabetics that he's tested [and he's tested loads!] have glucose values of about 4.7mmol/l most of the time.
My suspicion is that the targets set by US and UK "experts" were originally selected to be easy to achieve, so the "poor patients" didn't have to make too much effort, or give up anything and so the drugs companies could sell the most medicines.And of course until recently, home BG meters didn't exist and urine testing is very inaccurate as a guide to control.
In my mind, the only sensible TARGET is NORMAL non-diabetric numbers. I don't mean that all of us should achieve them all the time. I'm sure we can't. some people do though!, but what is the point of setting a target so high for a diabetic on treatment, that if that person were not being treated, they would be diagnosed diabetic?
Hana