Mean glucose concentration

Hi. I don't really know what that means - not seen anything like that. If it's a "mean" of anything then it would be an average of a number of readings, presumably.

HbA1c is not an average of anything, although it does give a good estimate of blood glucose levels over the past three months or so. Secondly as HbA1c and fingerprick tests are measuring different things to arrive at a blood glucose value, there is limited read-across.

115mg/dl is about 6.3mmol/l - same test, but different units. Although you'll often see graphics which seem to suggest you can read across from a fingerprick test and get an (estimated) HbA1c, experience (mine and many other folks on this forum) is that while it might give you a clue where your HbA1c might be, it will be only in very broad terms.

My fingerprick testing is fairly predictable these days, but over the last five years with no change in routine my HbA1c has wobbled around 38, with a low of 35 and a high of 40. This is probably partly due to testing error, I think.