Big difference between hospital Mmol readings and Wavesense Jazz

[Ashleyh]

Hello. Brief background. Diagnosed with Type 2 diabetes on October 17th 2017 with an HBA1C of 89.
I had been living on a diet of 2 to 3 litres of lucozade a day, plus sugary coffees and fast food etc to keep going visiting my Mum in hospital every day for the preceeding 3 months with a lot of driving each day.
Put on Metformin that day, but has a bad reaction, resulting in an ambulance ride and the subsequent discovery of an underlying heart condition called SVT. So had to manage my diabetes only by diet control, at least until I was able to have heart surgery for SVT.

OK, so diet control going quite well, at 3 month retest of my HBA1C in mid January 2018 it was down to 56. Still strongly diabetic, but quite a drop.

So have spent 6 days in hospital over the past couple of weeks having surgery for my SVT (abnormally fast heart rate spikes) which had a few complications. Informed nursing staff I was type 2 so they tested me 3 to 4 times a day. Towards the end of my stay nursing staff started feeding me some biscuits as they were concerned by low blood sugar readings well under 4 Mmol. Surprised by this as I had just taken a reading on my Jazz which gave 6.1 Mmol.

So next day similar issue. Hospital read my Mmol at 5.6 I did an immediate double check with my Jazz and it gave 9.1.
Nursing staff asked me if I was sure I was diabetic as during my stay all the hospital readings had been in the range 4 to 5.6 Mmol , apart from the one hypo reading. So I am confused. We were able to correlate some further readings taken during my stay, and my Jazz readings were always at least 2.5 Mmol higher than the hospital readings.

At the time I got my second HBA1C reading of 56, the Jazz was saying my 90 day average was 11.4, but hospital staff said an HBA1C reading of 56 equates to an average Mmol of around 9. We are 2 months on from that now and my Jazz meter is giving the following averages
14 Day 7.7
30 Day 8.1
90 Day 9.0

Also during my hospital stay I was not able to have my normal diabetic diet of low carb bread etc and was encouraged to eat the normal menu, including some deserts.

So I am guessing it would be wise to try a different meter and try and persuade my GP to let me have another HBA1C test in mode April which would be 6 months post diagnosis. Though apparently my 3 month drop from 89 to 56 meant I didn’t qualify for a further follow up HBA1C.

Any thoughts welcomed please, has anybody experienced similar over readings with a Wavesense Jazz?

Thank You
Ashley

 

[phdiabetic]

I've never heard of this meter, but some suggestions:
-can you use some control solution to check if your meter is working properly?
-have you got another meter you could use to test?
-are you washing your hands when you test on your own meter?
-do your physical symptoms match up with the values on your own meter? With the values at the hospital?

 

[Ashleyh]

There is a bottle of control solution in the meter’s box I will read up on how to use it.

I can borrow a different meter, though we did check my meter against the hospital ones.
Is there a particular recommended meter?

I mostly wash my hands, but not always.

I don’t normally have any physical symtoms these days. I was going to the toilet a lot and drinking gallons(of sugary drinks!)
before diagnosis. I did feel giddy and light headed when I had my Hypo/low sugar experience this week.

I do also have urine test strips, which are effectively telling me nothing since Christmas, as they don’t change colour now. Though I understand the renal threshold is about 10 Mmol?

 

[EllieM]

Towards the end of my stay nursing staff started feeding me some biscuits as they were concerned by low blood sugar readings well under 4 Mmol. Surprised by this as I had just taken a reading on my Jazz which gave 6.1 Mmol.

Hmm, were you any diabetic medication? Insulin or blood sugar lowering pills? I don't see how you could be hypo if you weren't....

 

[acs1951]

That reading of 56 is pretty good in such a short time as it takes time for the body to adjust. I may be that this will come down again so you will be back in range. Peraonally i take little notice of odd high readings but try to note what foods cause the spikes and avoid them or substitute low gi options. Meters are not 100% accurate so it is worth taking that into account.

 

[catinahat]

Hello Ashleyh welcome to the forum
Comparing meters will always lead to confusion, when you consider that all the machines have to comply to the industry standards for accuracy of plus or minus 15%. So one could be up to 15% over, the other 15% under. Then if you take into account other factors such as contamination on your fingers and the possibility of a faulty strip, it is unlikely that any two meters will give the same reading.
I think that as you are T2 with a Hba1c of 56, no medication, it is highly unlikely that you would be getting anywhere near to hypo levels. It is more likely that the hospital's machine was reading low.

 

[Ashleyh]

Hi EllieM. Not knowingly on any diabetic meds, but would have had quite a lot of other meds during my two operations.
I know at different times I had stuff to both thin my blood, and later coagulate it. I guess that could have thrown my readings. Have been a bit ill. Managed to get a puncture in my femoral artery as well!

 

[Ashleyh]

Thanks catinhat, my first thoughts were that the hospital readings were too low. But they told me they use “coded machines”, whatever that means, and during my stay I was tested with 3 different machines.

Anyway, I guess it seems likely that other drugs may have artificially lowered my BG levels. Though my Jazz was showing a higher 90 day average in January than my HBA1C, if 56 really does equate to 9 Mmol?

Anyway, I raised this thread because I am keen to get my monitoring right, as I have still been advised not to risk any diabetic meds. I will check my meter with the test solution as suggested above, and also borrow a different meter.

Thanks again everyone!
Ashley

 

[catinahat]

Have been a bit ill. Managed to get a puncture in my femoral artery as well!

Illness and stress will cause high glucose levels so it's looking even more likely that your meter was giving you a accurate reading and it's the hospital that needs a new one

 

[Bluetit1802]

Thanks catinhat, my first thoughts were that the hospital readings were too low. But they told me they use “coded machines”, whatever that means, and during my stay I was tested with 3 different machines.

Anyway, I guess it seems likely that other drugs may have artificially lowered my BG levels. Though my Jazz was showing a higher 90 day average in January than my HBA1C, if 56 really does equate to 9 Mmol?

Anyway, I raised this thread because I am keen to get my monitoring right, as I have still been advised not to risk any diabetic meds. I will check my meter with the test solution as suggested above, and also borrow a different meter.

Thanks again everyone!
Ashley

Yes, an HbA1c of 56 corresponds to 9mmol/mol

It is very rare that average meter readings will estimate a correct HbA1c because you would need to test many, many times, night and day, to be truly accurate. The 90 day meter averages are just a guide to show trends for us, they are not intended to be an accurate estimate of the HbA1c.

Because you have been in hospital and had all these heart problems and complications, I am certain your surgery will allow you an HbA1c test, especially if you go for the "I am really worried" stance. It will be worth asking.

I hope you are well on your way to recovery.