BG to HbA1c conversion

[Jamesuk9]

According to my Freestyle Libre, my HbA1c should be 28 mmol/mol, but the lab results are usually around 39 mmol/mol. I must be a high glycator or my red blood cells live longer than an average person's.

Or, as is commonly known the libre is anything but accurate, and is more beneficial for identifying trends... Just saying...

 

[NoCrbs4Me]

Or, as is commonly known the libre is anything but accurate, and is more beneficial for identifying trends... Just saying...

My glucose meter readings match my FSL readings pretty closely:

Don't mind the spikes - I was just seeing how I respond to carbs since I had a Libre sensor going. Other than this experimenting, I'm still zero carb.

 

[AM1874]

Hi @AM1874 Your readings are most impressive especially the postprandial which have very little variation, do you eat the same thing at every meal? You really do seem to have achieved excellent control, it would be interesting to know what happened if you now had something high carb like mashed potato. Regarding the Hba1c, it is of course not an average BG level, but an indicator of an average BG level. In your case because your readings are so consistent there is probably a good correlation but for someone with a big variation it would be necessary to derive the average from say hourly readings day and night to accurately predict Hba1c.

Hi @Mr_Pot
Thanks .. you are right .. my readings do not (and have not) varied by more than a point or two. I have never had a "spike" or a "hypo" and, in fact, all I know about them is what I have read on here. My LCHF diet is well varied and I eat a different meal every day, ranging from gammon, chicken, ham, tuna, lots of eggs and lots of salad to full English breakfast (minus hash browns and beans), burgers (minus bun) and steak with a good mix of above ground veg.
I take your point about seeing what might happen if I ate something high-carb but, for now, I'm taking an "if it ain't broke - don't fix it" position. I'll let you know if I change my mind ..

 

[AM1874]

Many thanks to ..
@Jamesuk9 @Avocado Sevenfold @bulkbiker @Mr_Pot @NoCrbs4Me @Yai @wiseowl_123
Thank you all for your invaluable advice, information and support on this thread .. it's really appreciated and reinforces for me just how important this forum is.
I am aware that my converted HbA1c readings may not be as accurate as lab tests but I have decided to accept them for what they are .. a strong indicator that I am now in control of my diabetes because of my LCHF diet, lifestyle changes, exercise and positive attitude
Thanks again

 

[Jamesuk9]

Just noticed @AM1874 14 Kilo weight loss too in 2 months..... You really have thrown the kitchen sink at it man.... So pleased for you, shining example of what commitment and effort can do. Congrats again.

 

[AM1874]

Hi @Jamesuk9 .. thanks again

 

[Bluetit1802]

@AM1874

Your readings are brilliant, very well done. It does seem you are heading for a great HbA1c and you deserve it with your commitment and hard work.

I would like to add that for me, my HbA1c has never been anywhere near my meter averages, and boy do I test a lot and average everything in sight. My current HbA1c is 41, which equates to 6.8mmol/l. I find this impossible because

1. All my FBG, bedtimes, overnights and before all 3 meals are 4s and low 5s. Randoms are in the 5s.
2. Current average of FBG, pre all meals and bedtime is 5.3
3. Overnight I drop to low 4s and some high 3s. I am in bed for 8 to 9 hours. (adjusted Libre readings)
4. Post meals at an hour and at 90 minutes are normally well under 7. (I do have an occasional hiccup) Back down by 2 to 2.5 hours.
5. I am also old school. All my tests (up to 10 a day until very recently) are on a spread sheet and each are averaged over a week, a month, and 3 months
6. My intermittent Libre useage gives me an estimated HbA1c of around 30. My Libres have always read low. Adjusted to correspond with my meter this would be around 35. (I diligently compare my Libre to my meter to see how different they are and work out the average differences)
7. I use the Accu Chek Mobile and the Codefree meters, comparing them to each other. (AC Mobile reads lower than Codefree)

So how can that average out at 6.8? Impossible. It has been like this since the start of my journey 3 years ago. All I can conclude is my red blood cell life does not fall within the standard 2 to 3 months used by the powers that be and I am a high glycator.

 

[Jamesuk9]

@AM1874

Your readings are brilliant, very well done. It does seem you are heading for a great HbA1c and you deserve it with your commitment and hard work.

I would like to add that for me, my HbA1c has never been anywhere near my meter averages, and boy do I test a lot and average everything in sight. My current HbA1c is 41, which equates to 6.8mmol/l. I find this impossible because

1. All my FBG, bedtimes, overnights and before all 3 meals are 4s and low 5s. Randoms are in the 5s.
2. Current average of FBG, pre all meals and bedtime is 5.3
3. Overnight I drop to low 4s and some high 3s. I am in bed for 8 to 9 hours. (adjusted Libre readings)
4. Post meals at an hour and at 90 minutes are normally well under 7. (I do have an occasional hiccup) Back down by 2 to 2.5 hours.
5. I am also old school. All my tests (up to 10 a day until very recently) are on a spread sheet and each are averaged over a week, a month, and 3 months
6. My intermittent Libre useage gives me an estimated HbA1c of around 30. My Libres have always read low. Adjusted to correspond with my meter this would be around 35. (I diligently compare my Libre to my meter to see how different they are and work out the average differences)
7. I use the Accu Chek Mobile and the Codefree meters, comparing them to each other. (AC Mobile reads lower than Codefree)

So how can that average out at 6.8? Impossible. It has been like this since the start of my journey 3 years ago. All I can conclude is my red blood cell life does not fall within the standard 2 to 3 months used by the powers that be and I am a high glycator.

If I'm interpreting this correctly, it would seem that your red cell life must be a lot longer than 3 months... There can be no other explanation.

 

[Bluetit1802]

If I'm interpreting this correctly, it would seem that your red cell life must be a lot longer than 3 months... There can be no other explanation.

I know from my full blood counts that my MCH (mean corpuscular haemoglobin) calculation is either above the standard range or teetering on the edge of it. It should be 27 to 32. Mine has been over 30 since at least 2013, and is often between 32 and 34. I have no idea if this is a reason - I THINK it means I have more haemoglobin than standard. Therefore more of it to glycate.

Does that make sense?

 

[Jamesuk9]

@Bluetit1802 If you're above the standard range it must have some bearing... Makes sense that the formulae used is calculated against blood that sits mid range of the markers the matter.

I'd be gutted as you clearly have incredibly good control otherwise.

 

[Bluetit1802]

@Bluetit1802 If you're above the standard range it must have some bearing... Makes sense that the formulae used is calculated against blood that sits mid range of the markers the matter.

I'd be gutted as you clearly have incredibly good control otherwise.

I have learnt not to get downhearted with my HbA1c results, and all but ignore them. They have all been higher than expected. However, because I most likely do have more glycation I must be more at risk of damage I suppose, so very important for me to keep good control as per my meters and Libre. I have no idea really, but logic tells me this.

I also know I'm not the only one on this forum with a similar problem. Conversely there may be some lucky ones with fewer haemoglobin cells and therefore producing low HbA1cs.

 

[AM1874]

Hi @Bluetit1802 and @Jamesuk9 ..
I guess that I will just have to wait until my next review to find out whether my lab-test HbA1c matches my conversion calculation. This is due early June but following up on a suggestion from @Jamesuk9 I will be contacting my surgery asap to see if this can be brought forward.
I will let you know ..

 

[Bluetit1802]

Hi @Bluetit1802 and @Jamesuk9 ..
I guess that I will just have to wait until my next review to find out whether my lab-test HbA1c matches my conversion calculation. This is due early June but following up on a suggestion from @Jamesuk9 I will be contacting my surgery asap to see if this can be brought forward.
I will let you know ..

Don't forget to leave a 3 month gap between your last one and your next one. Less than 3 months and you may have some old glycation there from before you started all this.

 

[AM1874]

Don't forget to leave a 3 month gap between your last one and your next one. Less than 3 months and you may have some old glycation there from before you started all this.

A bit tricky @Bluetit1802 .. it's only 2 months since my diagnosis (Feb 7th) .. I take your point, though and I will see what Doc says ..