Query Libre 3 readings

[Primear]

A new arrival on this thread and to the site.
My Libre 3 readings simultaneously show the following:
HOME 6.6 mmol/L = Normal range
AVERAGE 6.5 mmol/L = Normal range
GMI 6.1% mmol/mol = mid prediabetes
Which reading (s) is correct?
Why different readings??
Thank you for your help.

 

[EllieM]

Hi @Primear and welcome to the forums. At a guess (and I use a different cgm system)

HOME current blood glucose reading
AVERAGE average blood glucose reading
GMI glucose management indicator , libre estimate of your hba1c value (sort of) using US units (a %). 6.1% is 43mmol/mol using UK units.

Be aware that cgm estimates of hba1c aren't desperately accurate though, and can vary quite a bit.

 

[Primear]

Many thanks EllieM,

My GP has directed me to the Diabetes website for general info.
I am Pre Diabetec according to my GP.
I decided to incorporate the Libre 3 Sensor and I am trying to understand the information that the data imparts.
So 6.1% GMI on the Libre 3 translates to 43 mmol/mol.
Now here is my problem. HOME and AVERAGE are safely within a Normal BG reading.
But 43 mmol/mol is way over Normal yet not breaching the Diabetes threshold.
I am just querying the conflicting data but recognise your comment that accuracy is challenged.

 

[EllieM]

Average blood sugar for a non diabetic is typically around 5.5mmol/L
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7296129/

Here is a converter between the various units of hba1c and "average glucose"
https://www.diabetes.co.uk/hba1c-units-converter.html

They have 43mmol/L corresponding to an "average" glucose of 7.1mmol/L

It's a bit higher than the average showing on the screen, but GMI doesn't correspond to hba1c that well, so I wouldn't be too bothered by that, since they aren't really measuring the same thing.

 

[sgm14]

So 6.1% GMI on the Libre 3 translates to 43 mmol/mol.

You are not the only one who gets confused about this. If you look carefully you will notice the units for GMI is mmol/mol whereas your home screen and average figures are mmol/l (although you have to go to app settings to see this). So they are completely different scales.

So 6.1% GMI actually comes out at an average of 6.5mmol/l

The other issue that causes confusion is HbA1c/A1c which is another scale which has slightly different values from GMI The Libre always has an option for Estimated A1c which will give you another figure. An average of 6.5mmol/l should give a estimated A1c of around 5.7% or nearly 39 mmol/mol.

 

[Primear]

You are not the only one who gets confused about this. If you look carefully you will notice the units for GMI is mmol/mol whereas your home screen and average figures are mmol/l (although you have to go to app settings to see this). So they are completely different scales.

So 6.1% GMI actually comes out at an average of 6.5mmol/l

The other issue that causes confusion is HbA1c/A1c which is another scale which has slightly different values from GMI The Libre always has an option for Estimated A1c which will give you another figure. An average of 6.5mmol/l should give an estimated A1c of around 5.7% or nearly 39 mmol/mol.

Thank you for this clarity.

 

[Primear]

Thank you for this clarity.

Where can I locate in Libre 3 the option for Estimated A1c ?

 

[Antje77]

Where can I locate in Libre 3 the option for Estimated A1c ?

It's the GMI.

 

[TheSecretCarbAddict]

I never looked at the User Manual available under Help section in the app and when I did I discovered it is actually pretty good, answers most of the common questions and contains nuggets of information not readily available elsewhere. It takes you through the key information on how to use the app.

Abbot also have some self-paced learning modules that take you through different screens of the app, what they mean, and how to best benefit from these:
https://progress.freestylediabetes.co.uk/. Could be useful if you are completely new to this.