On 03/31/2013 09:10 PM, Jacquie wrote:
> My last two A1C's were 5.5 and 5.6 so I guess I'm doing ok 
I wish I had your numbers!
The following is just babbling. Skip it if you are in
a hurry.
Be careful of the A1C test as it is sloppy. It is based on
a red blood cell (erythrocyte) lifespan of 120 days. What
is not said openly is the plus and minus. If you look at
the ADA ("D" for Diabetis, not Dental) research on the
subject, you find a wide plus and minus in erythrocyte
lifespan:
http://care.diabetesjournals.org/content/27/4/931.full
The important part is on the second to last page:
We found a mean erythrocyte survival of 123 ± 23 days
(1 SD) in a study of 40 healthy control subjects using
the CO technique used in the present investigation, a
variability comparable to that observed with more
complicated methodology (16,17).
The 23 subjects with type 2 diabetes had a mean
erythrocyte survival of 112 ± 25 days, and only 2
subjects had survival values that were slightly
outside the normal range
So without knowing your particular "erythrocyte survival
rate", not so good information. (112 ± 25 days for T2's.)
When I showed my GP this research paper, his response
was "Oh it is even worse than you think. What we are
trying to do is to fit statistics from general population
to individuals." He then went on to talk about statistics
from a huge study done in England. Yikes!
But A1C can still be valuable if you compare it against
your previous tests to look for a pattern and against
your fasting blood glucose, then you start knowing your
own personal A1C and it has a lot of meaning.
I actually banged my A1c (6.1%) up again the alternate
Fructosamine test (227 umol/L). (Fructosamine measures
over a shorter period than A1C but I did nothing different
over either period.)
Your Fructosamine and your A1C are suppose to match based on
a formula in the reference below . Mine did not even come
close. As a matter of fact, my Fructosamine test showed me
as completely "normal" (190-270 umol/L, no jokes unless the
are funny). And when the two don't match, you are considered
to be in "Discordance" and I am "big time".
http://care.diabetesjournals.org/con...1/163.full.pdf
My GP is reading over the Discordance paper to try and figure
out what the heck. My GP is a really neat guy. A true man of
science.
-T