Continuous Glucose Monitoring - your thoughts/experiences!!

I have a Dexcom CGM and I think everyone who wants one, should have one. It gave me incredible control, great insight into my diabetes and a lot of confidence to make changes to control for better.
In my opinion, if you can get one, I'd strongly advise it. The sensor is easy to put and you can easily forget it's there.
Be aware that the readings are not 100% aligned with BG readings and don't expect them to be - CGM gives you a slightly different information, but I think just as valuable.

Ps. I'm self-funding.

Hi Sking,

You could take a look at the Libre users' thread:

http://www.diabetes.co.uk/forum/threads/freestyle-libre-on-sale.65900/

The only really significant difference between the Libre and CGMs (correct me if I'm wrong) is that the Libre doesn't let you manually calibrate to blood glucose measurements, more's the pity (this was Abbott's big mistake). Because of that, the slightly different results you get from interstitial fluid rather than capillary blood are a bit harder to know how to handle. But it's still a very effective management tool if you're looking at effects and timing of injections and diet. Cost per year c £1,250 plus Optium strips so you have some reference points: the Libre always reads low and you don't want to run high.

LucySW said:

Hi Sking,

You could take a look at the Libre users' thread:

http://www.diabetes.co.uk/forum/threads/freestyle-libre-on-sale.65900/

The only really significant difference between the Libre and CGMs (correct me if I'm wrong) is that the Libre doesn't let you manually calibrate to blood glucose measurements, more's the pity (this was Abbott's big mistake). Because of that, the slightly different results you get from interstitial fluid rather than capillary blood are a bit harder to know how to handle. But it's still a very effective management tool if you're looking at effects and timing of injections and diet. Cost per year c £1,250 plus Optium strips so you have some reference points: the Libre always reads low and you don't want to run high.

Click to expand...

Libre is also missing the "continuous" part: it doesn't give you any alerts and you need to scan at least every 8h not to lose the results

Depends on what you're after. The Libre is brilliant if you haven't got a CGM and you aren't concerned about Hypo alarms (which I'm not). It gives you trend information and a large amount of useful data concerning how your glucose levels change with time relating to food and insulin that isn't available elsewhere. As such, it's an incredibly useful tool. Ignore the mismatch between bloods and interstitial fluid - it makes little difference once you actually start using the system.

If your primary reason for getting it is due to Hypos, then the Libre won't stand in for a Dexcom or other CGM. Otherwise it is a really great tool to help manage your glucose levels.

tim2000s said:

Ignore the mismatch between bloods and interstitial fluid - it makes little difference once you actually start using the system.

Click to expand...

Totally agreed - but the Libre's accuracy problems mean you need strips too. Eg yesterday morning at 10:11 saying 3.0 when two fingersticks at 10:13 were 6.9 and 6.3.

Sking89 said:

Hi

I was diagnosed 2 years ago with type 1 diabetes. I am 25. I have had pretty good control and good HBA1c results.

I had a rocky few weeks of blood glucose control during October. I can get quite panicky when going low, or the thought of going low, and feel it affects the quality of my life slightly as I am terrified to not have lucozade on me at all times. I know glucose tablets are easier to carry around but find lucozade works better for me.

Due to the above, I am thinking about speaking to my diabetic nurse about going on a continuous glucose monitor... I have previously been against it as I don't like the thought of having something continuously attached to me.

I was just hoping other people could share their thoughts and/or experiences of continuous glucose monitoring in an attempt to help me make my mind up....

Thanks in advance!!

Click to expand...

Good morning to you, I've had a cgm for quite a few months now and love it. You do have to remember though it lags about 20 mins behind a finger test. It's not always accurate so can read 5 and be 4.1 in real terms. Sensors as long as you place them carefully you just don't notice them. If you go for the Dexcom CGM they can be restarted after 7 days of use so you do get your monies worth from them I'm on 4 weeks and 4 days at the moment. Ask @PaulinaB how stick down a sensor she holds master classes lol.

CarbsRok said:

I'm on 4 weeks and 4 days at the moment. Ask @PaulinaB how stick down a sensor she holds master classes lol.

Click to expand...

Hahaha I only usually do 2-3 weeks as I'm a lazy bum... @Spiker does some real "maintenance" thing

LucySW said:

Totally agreed - but the Libre's accuracy problems mean you need strips too. Eg yesterday morning at 10:11 saying 3.0 when two fingersticks at 10:13 were 6.9 and 6.3.

Click to expand...

This is what I find quite odd. I've not seen anything like this level of disparity. It would be good to understand what causes the differences between Libre sensor readings and blood glucose tests. My suspicion is that the reading in the Interstitial Fluid is, in fact, accurate, but we are not accustomed to calibrating ourselves on that.

tim2000s said:

This is what I find quite odd. I've not seen anything like this level of disparity. It would be good to understand what causes the differences between Libre sensor readings and blood glucose tests. My suspicion is that the reading in the Interstitial Fluid is, in fact, accurate, but we are not accustomed to calibrating ourselves on that.

Click to expand...

I think what I described with my sensors, grrrrr, is a defect issue. I too think that it's better just to accept the ISF contour as the valid guide in question, rather than 'translating' it all the time. As DunePlodder said and many of us have found, systematically testing different blood meters against one another on the same drop of blood generally produces little more than intense frustration. Craving a fine level of accuracy doesn't mean we're going to get it - for now, at least.

I fingerstick now to see what my fasting BS is as an absolute number, because I need to know that, because I need to lower it. I've stopped translating to and fro.

At present, there are no guidelines recommending CGMs so it is extremely unlikely that the NHS will pay for one, and unfortunately they are also very expensive. The Libre is an order of magnitude cheaper.

My suspicion is that the reading in the Interstitial Fluid is, in fact, accurate, but we are not accustomed to calibrating ourselves on that

Click to expand...

That's irrelevant - the sensor measures something, and the resulting current is converted to a blood glucose reading using some algorithm; whether the sensor is accurately measuring something doesn't matter if it's not correctly translated to a usable blood glucose number.

This could be due to a problem with the algorithm, a problem with the sensor, or maybe something else. Given that I had massive problems with my first sensor (readings 5mmol/l below the true value for 5 days) but little trouble with the next two, I'd bet on faulty sensors.

Older CGMs try to estimate current blood glucose based on interstitial readings *and* calibration data (essentially, knowing that your prediction was off this time helps you make the next one more accurate), and Abbot seems to be trying without calibration for the Libre; mathematically, the prediction cannot possibly be as good, but I guess they think it's good enough.

I think Alex, this is where everyone has made an error. I've had a good read through the available literature and Abbott don't mention Blood Glucose. They simply say Glucose. Then, in the main text plus multiple footnotes and references, they state that it is indicated for "measuring interstitial fluid glucose levels". The units are those in which fluid glucose levels are measured, whether in blood or interstitial fluid.

While I don't doubt that there has been a batch of sensors that didn't appear to work properly, Abbott have taken great care in the literature to NOT state that blood glucose is being measured/given, so the measurement on the screen of the reader is not the blood glucose level, but the interstitial fluid glucose level.

I've used CGM for nearly 4 years now as I have no hypo awareness and am reliant on it to predict when I'm going hypo and also to suspend insulin delivery to my pump when my glucose falls below a certain level. It has worked brilliantly for me, I've only needed help with a handful of hypos since using it. It provides a 24 hour picture into the secret life of glucose levels and is a real eye opener as to what goes on in between the snapshot blood glucose tests we do.

Ask your diabetes clinic if they can loan you a CGM for a week to see what you think of it and if it might help you before considering investing in a system

Abbott have taken great care in the literature to NOT state that blood glucose is being measured/given, so the measurement on the screen of the reader is not the blood glucose level, but the interstitial fluid glucose level.

Click to expand...

Of course - the Libre does not directly measure blood glucose; instead, it measures interstitial fluid levels which are known to be related to current blood glucose levels and estimated blood glucose based on that.

However, your conclusion that the meter displays the raw data is silly - displaying raw input data known to NOT be BG leves in exactly the same way BG levels are displayed would be grossly negligent (as shown in this thread, everyone assumes that the 5mmol/l readings are for blood glucose).

Besides, what would be the point of the device if the user has to do these complicated calculations in his head? You might just as well try to estimate your current glucose based on a thermometer reading.

AlexMBrennan said:

Of course - the Libre does not directly measure blood glucose; instead, it measures interstitial fluid levels which are known to be related to current blood glucose levels and estimated blood glucose based on that.

However, your conclusion that the meter displays the raw data is silly - displaying raw input data known to NOT be BG leves in exactly the same way BG levels are displayed would be grossly negligent (as shown in this thread, everyone assumes that the 5mmol/l readings are for blood glucose).

Besides, what would be the point of the device if the user has to do these complicated calculations in his head? You might just as well try to estimate your current glucose based on a thermometer reading.

Click to expand...

I think you misunderstand my point. I am not suggesting that it displays the raw input value (that would be a current of some level that would be nigh on impossible for the average joe to understand and to calculate something useful from).

I am suggesting it works in a very similar way to a blood glucose meter, using an enzyme to generate a current that is then converted to units that we understand. What it is not doing, and has never said it is doing, is displaying the blood glucose level, or estimating the blood glucose level.

It is displaying the Interstitial Fluid level in units that we understand from our use of them in urine and glucose testing. There is no algorithm to convert the IFG to a BG.