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OGTT and CGM?

LittleGreyCat

LittleGreyCat

Well-Known Member
Retired Moderator
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4,426
Location
Suffolk, UK
Type of diabetes
Type 2
Treatment type
Tablets (oral)
Dislikes
Diet drinks - the artificial sweeteners taste vile.
Having to forswear foods I have loved all my life.
Trying to find low carb meals when eating out.
Just had a thought (rare for me).

A standard OGTT involves lots of blood testing at short intervals to get a profile of your insulin response.

Would it not be more efficient to fit the testee with a CGM sensor (perhaps the day before), calibrate it at the start of the test and then use the readings?

Much less invasive than the regular finger pricking and if done properly you could get a continuous readout.

£30 or so for the sensor is a trivial cost compared to all the other stuff going on.
 
You would think so, wouldn't you!
However, there's always one or two buts ain't there?
I have only had a extended OGTT, and a cannula is fitted for venous blood samples.
The glucometer they use is a really good piece of equipment and more sensitive than any other blood glucose monitor.
Others might disagree, but cgms can give a wider range just like a glucometer used at home.

But it should be possible soon enough as the technology is making great strides in non invasive testing machines.
 
The standard OGTTs I had were in my doc surgery administered by one of the nurses.
They involved a prick test and a venous sample (for lab analysis) at the start.
Then the same again at 120 mins.
There was no interim testing (actually they sent me home to return at the end)

So I am guessing that didn’t cost them as much as the fitting, explaining, downloading data, etc. that would be involved in fitting a CGM (Libre).

But I certainly agree that it would be an economy to use it for longer tests.
 
I've had an OGTT in hospital. They fitted a canula and took blood every 15 mins. They did ask me finger prick test a few times too just to check I wasn't going too high. It's the consistency of the lab testing that's important - any of our machines have a bigger error margin.
 
I think we might be rather surprised how many OGTTs are actually done, bearing in mind they will be done for gestational diabetes as well as a raft of other things. The time and cost of supplying and fitting the CGMs + training of staff, plus the likely ongoing need for the start and any critical point bloods still being done, the costs would be huge, versus the true clinical benefits.

A finger prick test, placement of a cannual and the clipping on and off of a couple of vaccuvials is likely to be much less.

I would consider the NHS to be some way away from that particular change.
 
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