# Re: [IPk] BGs and HbA1c

```Hi Tori,

This seems to be the same as my chart (my chart is whole blood, which is
what I use (I convert from mg/dl plasma to moll whole, as I can't think
of moll plasma!).  But it reads 'too low' for me: at my last clinic
visit my meter average (10.0), by this formula, would give a hba1c of
8.0, but actually it was 7.3.  The previous visit, my meter (average
8.8) suggested the hba1c would be 7.3, but it was only 6.8.

As I've said before, I need time to look at my statistics, and put
together a research agenda, set up the experiments, etc.

Me, I'm just glad that 10.00 is the highest meter average I see
nowadays.  I _never_ saw a single digit average on mdi.

Best wishes,

Pat
(dm 30+, 508 2+)

In message <email @ redacted>,
Tori <email @ redacted> writes
>I've actually managed to predict accurately my last 2 HbA1c's, using the
>following formula. (I use a Medisense Optium - also called a Precision Xtra
>- meter, but these seem to work for most meter readings. It will depend
>somewhat on how often you test, but it gives reasonably accurate ball park
>numbers for most - meaning people who test 3-6x/day or more). The "average
>BG reading" is the average over the last month.
>
>Using plasma glucose readings (which most meters these days measure, but
>your meter manual/guidelines should tell you whether it measures plasma or
>whole blood):
>
>HbA1c = (average blood glucose {in mmol/l} + 4.2944)w 1.9777
>HbA1c = (average blood glucose {in mg/dL} + 77.3)w 35.6
>
>If you use an older meter which measures whole blood - and some newer ones,
>including the Optium, for example - the mean (average) glucose reading
>measures lower and so the HbA1c is actually higher than results using the
>above formula. The below should be used:
>
>HbA1c = (average blood glucose {in mmol/l} + 4.778)w 1.85
>HbA1c = (average blood glucose {in mg/dL} + 86)w 33.3
>
>I'd be interested to know if others find these accurate or if it's just me!
>
>Tori
>
>At 07:01 PM 20/07/2003, you wrote:
>>Yes, of course, I'd already writen too much, and the difference between
>>the hba1c and meter average (even if the meter is used every hour, and
>>at no other time) is something which has a far bigger impact, of course
>>(and one can set one's meter average on the computer to whatever one
>>likes, at least with my meter: on meter it's 2 weeks, though.  It would
>>be nice to have a 'mimic the hba1c and predict it' function, too ...
>
>http://www.hypostasis.info
>Peer support for Type 1 diabetics, friends, family and others
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--
Pat Reynolds
email @ redacted
"It might look a bit messy now,
but just you come back in 500 years time"
(T. Pratchett)
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