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First CGM

T

timbo_dolman

Well-Known Member
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Just ordered a Dexcom one plus CGM to help me manage blood sugar levels (currently T2 controlled with low carb and exercise). Any tips on the use of monitors to get the best out of it would be most appreciated. Thanks
 
Hi @timbo_dolman, to maximise the insight generated, I'd be ready to track your nutrition (timing, size, and macronutrient ratio of your meals), exercise, sleep, stress levels and any medication you might be taking. Overlaying this on top of your CGM blood glucose curve will give you a detailed insight into what impacts your blood glucose and how much. The only other thing to say is to get yourself a glucometer to benchmark CGM readings as sometimes they might be off depending on the sensor. While trends will probably be still valid, I've had occasions when my sensor has been running consistently 3 mmol/l higher than a fingerprick test.
 
Once you get used to using CGM and notice interesting patterns, you can run mini experiments.I did x and y happened. Now, let's keep everything the same but adjust x by z and see what happens. For example, you could adjust the amount of carbs in a meal or a duration of exercise to see how it impacts your blood glucose.
 
TheSecretCarbAddict said:
Once you get used to using CGM and notice interesting patterns, you can run mini experiments.I did x and y happened. Now, let's keep everything the same but adjust x by z and see what happens. For example, you could adjust the amount of carbs in a meal or a duration of exercise to see how it impacts your blood glucose.
Click to expand...

Great advice, thank you
 
For the first time using a CGM, it is VERY important to understand the limitations such as
- compression lows - when pressure is applied to a sensor, the filament is blocked form interstitial fluid so the sensor will report a false low.
- insertion trauma - the body can react to the alien object in your arm and take a day or two to get used to it. During this period, the readings could be irregular, Some people apply their sensor a day before activating to avoid this.
- abnormal range - CGMs are designed to be most accurate during "normal" BG which is typically between 4 and 10mmol/l. Outside this range, the highs and lows may be reported as more extreme.
- interstitial fluid delay prediction - CGMs do not read blood. They make a prediction based upon interstitial fluid, This is a prediction because changes in BG can take 10 to 15 minutes to register in interstitial fluid. Typically, the algorithm that converts interstitial fluid readings (ISR) to BG will extrapolate the current rend. This is not a problem most of the time unless the trend changes direction (e.g. you reach the peak of a spike and start going down) in the last 10 to 15 minutes. In this scenario, you may see a high BG "disappear" as the prediction catches up with real time.
- insufficient fat - the filament needs to sit within fat to access the interstitial fluid. If the filament does not have enough fat, the readings can be completely out and the sensor may fail.

If you ignore these limitations, you may find your CGM incredibly frustrating
 
GCMs are incredibly frustrating in any case, at least in my experience - but.... you can definitely gain real insight with them...

All the above is spot-on advice; I would only add that it's a tool for spotting patterns, and maybe a way to understand other signs that your body is telling your (why do I feel tired right now; oh, the trace is dropping fast after a rise...) - don't get too hung up on absolute numerical values.

If you are already controlling your T2 with low-carb and exercise, you are doing amazing work, and I hope this gives you the tools to fine tune...
 
Chris24Main said:
GCMs are incredibly frustrating in any case, at least in my experience - but.... you can definitely gain real insight with them...

All the above is spot-on advice; I would only add that it's a tool for spotting patterns, and maybe a way to understand other signs that your body is telling your (why do I feel tired right now; oh, the trace is dropping fast after a rise...) - don't get too hung up on absolute numerical values.

If you are already controlling your T2 with low-carb and exercise, you are doing amazing work, and I hope this gives you the tools to fine tune...
Click to expand...

Thank you - I’m going to try to experiment with some foods with it. I can go off the rails diet wise occasionally so this I hope, will help me manage and also keep me motivated
 
I think there is even space for some to have a little fun with this - it doesn't need to be all doom (though I don't mean to minimise anyone's experience) - going off the rails every once in a while is pretty much what makes us human.... embrace it!!

If you learn, it's always (well, usually at least) - worth the experience..
~and for the love of Betsy, understand that my tongue is well and truly in my cheek here...


...small print... of course, not all experiences are worth the value of learning from them...
 
In Response said:
For the first time using a CGM, it is VERY important to understand the limitations such as
- compression lows - when pressure is applied to a sensor, the filament is blocked form interstitial fluid so the sensor will report a false low.
- insertion trauma - the body can react to the alien object in your arm and take a day or two to get used to it. During this period, the readings could be irregular, Some people apply their sensor a day before activating to avoid this.
- abnormal range - CGMs are designed to be most accurate during "normal" BG which is typically between 4 and 10mmol/l. Outside this range, the highs and lows may be reported as more extreme.
- interstitial fluid delay prediction - CGMs do not read blood. They make a prediction based upon interstitial fluid, This is a prediction because changes in BG can take 10 to 15 minutes to register in interstitial fluid. Typically, the algorithm that converts interstitial fluid readings (ISR) to BG will extrapolate the current rend. This is not a problem most of the time unless the trend changes direction (e.g. you reach the peak of a spike and start going down) in the last 10 to 15 minutes. In this scenario, you may see a high BG "disappear" as the prediction catches up with real time.
- insufficient fat - the filament needs to sit within fat to access the interstitial fluid. If the filament does not have enough fat, the readings can be completely out and the sensor may fail.

If you ignore these limitations, you may find your CGM incredibly frustrating
Click to expand...
Fascinating thank you . Every day is a school day for me
 
timbo_dolman said:
Just ordered a Dexcom one plus CGM to help me manage blood sugar levels (currently T2 controlled with low carb and exercise). Any tips on the use of monitors to get the best out of it would be most appreciated. Thanks
Click to expand...

How are you getting on with the Dexcom 1+? I've been using the libre2+ and find that very helpful. I received a Dexcom1+ today as I noticed how much cheaper it is on the monthly subscription than Libre 2+ but having read the instructions, I noticed a warning about the sensor wire breaking off under the skin. Has anyone had this happen to them?
 
It’s going okay with no problems at all with the sensor breaking off. Found it to be really good in planning meals and seeing what causes spikes. The only issue I’ve had is when I’ve put a replacement sensor on them for first 24 hours it gives strange readings until it settles down so I have to calibrate it with a finger prick test. Not a big issue, but you feel like you lose a day of the sensor. Other users have had the same.
 
timbo_dolman said:
It’s going okay with no problems at all with the sensor breaking off. Found it to be really good in planning meals and seeing what causes spikes. The only issue I’ve had is when I’ve put a replacement sensor on them for first 24 hours it gives strange readings until it settles down so I have to calibrate it with a finger prick test. Not a big issue, but you feel like you lose a day of the sensor. Other users have had the same.
Click to expand...

Thanks for the quick response . I'm going to attempt the Dexcom 1+ today. I do find using the Libre sensor, it does keep me motivated and on track.
 
I’ve tried the Libre 2, my diabetes nurse decided to get me a couple of sensors to see what was going on with my levels, T2’s don’t get them on prescription unless your on insulin, I think. So, I ended up pricking as well, only 2-3 times a day as I wasn’t sure the readings were right with the Libre, I suppose I didn’t have a real good understanding of their working method, I knew it took reading from the interstitial fluid and not blood but didn’t know results lagged. So, decided to maybe only buy the monitors occasionally, I’ve one in the cupboard. The results were sent direct to the surgery so my nurse could see the patterns, she’s very good I’m lucky. I think maybe when I go away, the monitor may be useful. My husband helped me look at the benefits of both the Libre 2 and Dexcom and it looked like the Libre 2 was slightly better.
 
Angela64 said:
I’ve tried the Libre 2, my diabetes nurse decided to get me a couple of sensors to see what was going on with my levels, T2’s don’t get them on prescription unless your on insulin, I think. So, I ended up pricking as well, only 2-3 times a day as I wasn’t sure the readings were right with the Libre, I suppose I didn’t have a real good understanding of their working method, I knew it took reading from the interstitial fluid and not blood but didn’t know results lagged. So, decided to maybe only buy the monitors occasionally, I’ve one in the cupboard. The results were sent direct to the surgery so my nurse could see the patterns, she’s very good I’m lucky. I think maybe when I go away, the monitor may be useful. My husband helped me look at the benefits of both the Libre 2 and Dexcom and it looked like the Libre 2 was slightly better.
Click to expand...

That’s great . I’ve calibrated the Dexcom against finger prick test a few times and it’s remarkably accurate actually. I think I’ll probably use it for a few months and then go back to fingerprint test but it’s nice not to be doing that regularly.
 
timbo_dolman said:
That’s great . I’ve calibrated the Dexcom against finger prick test a few times and it’s remarkably accurate actually. I think I’ll probably use it for a few months and then go back to fingerprint test but it’s nice not to be doing that regularly.
Click to expand...
My fingers hate the pricking, can bruise me I believe the Dexcom IS. A continuous glucose monitor wereas the Libre is a flash monitor, that is, its not continuously taking readings .
 
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