Confused by units to Measure Blood Glucose Levels

[Robert Hancock]

5.2 mmol/L this a.m. (Sun.)

Been a week since taking one... another episode I'm afraid.

Sorry to ask, but where do you get mmol/L units from? Do you mean mmol/mol which is the new recommended European standard (see attached) versus the derived NGSP (%) standard?
Extract:
HbA1c determination to the IFCC1 reference measurement procedure, using the new unit mmol/mol. Since these new values in mmol/mol differ from values determined by the standardization according to NGSP2, it is recommended that HbA1c results should be reported in both units, mmol/mol (SI unit) and derived NGSP units (%).

 

[lovinglife]

As this is a UK forum most of our members quote HbA1c numbers as mmol/mol and finger prick blood glucose tests as mmol/L
Here are a couple of articles which may help:

HbA1c Units Converter - DCCT to IFCC​

Since June 2011, the way HbA1c values are reported has switched from a percentage to a measurement in mmols/mol.

www.diabetes.co.uk

Blood Sugar Glucose Converter for Diabetes​

Convert blood sugar/glucose from mmol/L (UK standard) to mg/dl (US standard) and vice versa using our blood sugar converter.

www.diabetes.co.uk

 

[Melgar]

@Robert Hancock, I wish they would standardize these blood sugar measurements. I live in Canada where we use mmol/ls, and % ‘s for our HbAc1 measurement. As @lovinglife points out in the UK it’s mmols/mol . In the US they use mg/dL. I have a blood sugar conversion table on my main screen for reference.

 

[Antje77]

Hi @Robert Hancock , I think you'll fiind this chart useful.
It has blood glucose in both mmol/l and mg/dl, and hba1c in both mmol/mol and %.

 

[KennyA]

Historically HbA1c was reported in percentage terms to indicate the percentage of haemoglobin that had been glycated - ie had a glucose molecule attached to it. This was derived from and aligned to the Diabetes Control and Complications trial (DCCT) which took place in the 1980s.

In June 2009 the UK adopted the newer International Federation of Clinical Chemistry (IFCC) system, and this was accepted internationally in 2011. It established a new reference system, and values are supposed to be reported now in terms of millimol HbA1c (glycated haemoglobin) per mol haemoglobin (without glucose attached) (info from Bilous and Donnelly)

As usual, some systems (most notably the USA) and some professionals within other systems (including the UK) have been very slow to change, and continue to use the old values they were trained on.

 

[Robert Hancock]

Wow, thanks for the tableI Antj77 and explanation KennyA. I didn't know about this international mix of units systems used for HbA1c and instantaneous BG. While this is a UK forum, how many international readers are there (like me) who must be confused to read of HbA1c levels of 110 when they are used to % values of 6?
So, two questions—my clinic in Japan tells me that HbA1c is an "index" expressing the percentage of glycated haemoglobin over the previous 3 months (some other experts say 1 month, but if it really is 3 months, the recent months must "weight" the index).
First, if this is correct, what is the point of posting daily HbA1c changes here, which can only vary slightly given the 3- or 1-month "inertia" in the index? Second, why not use instantanous fasting BG measured from a finger prick or CGM rather than convert the measurement to HbA1c because if the "index" has built-in inertia, it seems possible to have short-term high and damaging BG even while the HbA1c remains relatively unaffected (in the short term)?
I ask because I'm a CGM user so I tend to monitor BG changes on a more instantaneous scale than daily, weekly, monthly, and quarterly, and a CGM has really helped me consistently get to under HbA1c 6% rather be stuck at 6.9% and higher for years. On the downside, I'm not sure about the relative advantages/disadvantages of the OCD side effect of constantly knowing my BG.
As a last question, do many T2D people in the UK use a CGM and can they obtained from the NHS, or are only T1D people using CGM?
Sorry to ask so many questions.

 

[Rachox]

what is the point of posting daily HbA1c changes here

The daily fasting blood sugar threads which I think you are referring to are either finger prick tests or CGM reading measured in mmols/L.

 

[Melgar]

I’m in Canada , so our HbAc1’s are shown in percentages. @Robert Hancock you are right, even though HbAc1‘s show percentages over a three month period, (the lifespan of the red cells) it is heavily weighted towards the last month. It’s not ideal, and it is accepted that it is not ideal, but that is what many countries use as there system for determining how well you are controlling your diabetes over the last three months. It is also used to determine if you are diabetic or not.

Time in Range is a better indicator of how well you are controlling your blood sugars if you use a CGM. Many T2s use glucometers as CGM’s are not usually given on prescription in the UK, same in Canada. Some T2s on insulin do, but it seems to depend on the health authority From what I have read.

The discussion groups here where members share their blood glucose numbers are fasting early morning figures drawn from either a fingerprick or a reading from their CGM device.

 

[Robert Hancock]

I’m in Canada , so our HbAc1’s are shown in percentages. @Robert Hancock you are right, even though HbAc1‘s show percentages over a three month period, (the lifespan of the red cells) it is heavily weighted towards the last month. It’s not ideal, and it is accepted that it is not ideal, but that is what many countries use as there system for determining how well you are controlling your diabetes over the last three months. It is also used to determine if you are diabetic or not.

Time in Range is a better indicator of how well you are controlling your blood sugars if you use a CGM. Many T2s use glucometers as CGM’s are not usually given on prescription in the UK, same in Canada. Some T2s on insulin do, but it seems to depend on the health authority From what I have read.

The discussion groups here where members share their blood glucose numbers are fasting early morning figures drawn from either a fingerprick or a reading from their CGM device.

Thanks Melgar.

 

[Antje77]

how many international readers are there (like me) who must be confused to read of HbA1c levels of 110 when they are used to % values of 6?

You get used to the different numbers if reading enough about diabetes from international sources.
Just save that chart somewhere where you can quickly refer to it when reading, or even when writing.
It's perfectly fine to post about your blood glucose in mg/dl here, or about hba1c in %, but more people will instantly have a reference for your numbers if you add the mmol/l or mmol/mol as well, which can be useful if you have a specific question.

 

[EllieM]

If you are good at mental arithmetic it's quite easy to go from fingerprick mmol/L to fingerprick mg/dL, just multiply by 18. It's harder the other way round, dividing by 18, but not impossible, (I divide by 2 and then by 9).