Maybe it is not just BMI we need to question....
see http://care.diabetesjournals.org/content/40/8/994
see http://care.diabetesjournals.org/content/40/8/994
It's more that the only evidence recognised by NICE is based on the DCCT study, which has very clear correlations between lower A1C and reduced relative risk of complications.Unfortunately, I assume reflecting the lack of access, the NICE guidelines only focus on the HBA1C as the golden measure for all.
Also most people who get "improved TIR/reduced standard deviation" will also reduce their A1C and/or get the same AC1 using less insulin, hence when looking at groups of people A1C remains a very good predictor.
One large US study found that (in both Type1 and Type2) level of insulin usage was a better predictor of "length of life" than "great" AC1, e.g. people who used less insulin lived longer, however, AC1 is a very good predictor of complications (like going blind) that mostly don't kill people. Very bad AC1 is also a predictor of short life.
No one thinks a AC1 of 100 is OK, but is a AC1 of 45 any better than 50 on the individual level?
I found this, which frankly disappointed me as, based on my HbA1c, I thought I was doing ok, now I am not so sure.
http://www.gpnotebook.co.uk/simplepage.cfm?ID=x20070614192625295600&linkID=70250&cook=yes
There are many such articles. I have a whole collection of them. It is very well known that red cell life span is crucial. If it is not around the average of the general population, then the HbA1c can be skewed. Then we have red blood cell abnormalities, such as anaemia, high or low haematocrit levels, hypothyroidism, and similar.
Trust your finger prick measurements over and above your HbA1c (if you test regularly enough that is)
That's the problem. From extensive testing when I was diagnosed 2 years ago, I now only test occasionally if I have some new food to test or out of curiosity. The HbA1c test may have its limitations but it is probably better than trying to get an average from a few blood tests taken say just pre and post prandial. Also, even if you have a non standard life of red blood cells this is presumably constant, so at least HbA1c trends would be useful.Trust your finger prick measurements over and above your HbA1c (if you test regularly enough that is)
I feel like I'm being a bit paranoid but I keep worrying that I actually get bad numbers and there must be something wrong with me that makes HbA1c not work.