Average HBA1C

[Sebstar]

Can I anyone tell me if the average fbg on your blood glucose machine is a guide to what your HBA1C will be (my machine gives you an average over 30 days). My bg before breakfast is usually between 4.7 and 5.4 most days and I wondered if I could take this as a sign that I have reasonable control.

 

[sofaraway]

http://www.diabeteschart.org/bloodsugarchart.html

This chart might help,

or this calculator

http://www.phlaunt.com/diabetes/A1Ccalc.php

Those readings for fasting levels are very good. Are you testing at other times of the day and after meals? as these times will have an effect ont he A1c.

 

[Northerner]

There is a calculation you can do to relate your HbA1c to your estimated average from your meter:

MeterAverage(mmol/l) = 1.59 ? A1C − 2.59

So, if your HbA1c was 6.5 the calculation would be:

(1.59 x 6.5) - 2.59 = 7.75 meter average.

Heres a table that makes it easier:

HbA1c Meter reading
(%) (mmol/L)
5 = 5.4 (4.2–6.7)
6 = 7.0 (5.5–8.5)
7 = 8.6 (6.8–10.3)
8 = 10.2 (8.1–12.1)
9 = 11.8 (9.4–13.9)
10 = 13.4 (10.7–15.7)
11 = 14.9 (12.0–17.5)
12 = 16.5 (13.3–19.3)

 

[Cliff]

Sebstar - I think it can be a good guide if you have a good spread of readings. There are some formulae out there that will try to convert your average meter readings into an estimated HbA1c. I tried it recently using my 90 day average immediately preceding blood being taken and it estimated my HbA1c at 5.5% - my lab reading was 5.6% so in my case it came close.

The formula is BG = (1.583xHbA1c)-2.52 which if you rearrange gives HbA1c = (BG+2.52)/1.583. I have a spreadsheet set up for this which I find helpful.

 

[Northerner]

You explained it far better than me Cliff, thanks! 🙂

 

[Cliff]

Northerner - just a normal case of great minds thinking alike 😛

 

[wallycorker]

Can I anyone tell me if the average fbg on your blood glucose machine is a guide to what your HBA1C will be (my machine gives you an average over 30 days). My bg before breakfast is usually between 4.7 and 5.4 most days and I wondered if I could take this as a sign that I have reasonable control.

Hi Sebstar,

I'd certainly be expecting that to result in a great HbA1c somewhere in at least the mid 5s and possibly lower. However, how good it is will also depend on how high you are taking the levels after meals - that is important too.

I've found that my 'on rising' fasting level is a very good indicator of my overall control.

Sounds as though you have things fairly well under control. Well done!

Best wishes - John

 

[Sebstar]

I do take lots of readings 1 hour and 2 hour and sometimes 1 and a hallf hours after meals. I'm happy if I don't go into double figures and like to be below 8 after 2 hours I just wondered if the fasting one first thing in the morning was significant. I'm hopeless at maths. I'm not on any medication at the moment and not due for a review till the end of April so am getting a little anxious that I think I am doing ok when maybe I'm not. Thanks for all replies.

 

[wallycorker]

........I'm happy if I don't go into double figures and like to be below 8 after 2 hours ...........

That's basically where I started from. I then started to look for being below 8 one hour after eating and that's where I am these days.

You sound to be doing OK! I'd say don't get too anxious about it just keep trying to improve your levels slowly.

Best wishes - John

 

[Cliff]

Sebstar - I'd be really pleased with fasting levels like the ones you're producing - I'm consistently in the 6s, almost never in the 5s, and occasionally in the 7s. I still managed a 5.6% HbA1c last time round.

If your post-prandial levels are not too high I think you may well be on target for a seriously good result.