Is this typical dawn phenomenon?

[Emilymay]

Hi, applied my Libre 2 sensor for the first time last night before bed, I’ve read about dawn phenomenon and have done some finger prick readings while waking/ mid morning but never with this level of constant monitoring. Is this typical dawn phenomenon. It’s 08:55 and I seem to be sitting at constantly around 6 and have done for the past 45 mins ish.
Is there a way to stop this without medication or is it normal? My log book shows it more quickly if you can see over the dots. I’ve gone too excited with scanning, ha.

 

[Robin]

It’s difficult to draw conclusions from one night's readings. I think you need to see if the pattern is repeated over subsequent nights.
Two initial observations, though.
1) The big dip and rise, between 4.30 and 5am could be a 'compression low' where you lie on the sensor and squish the interstitial fluid that it relies on to read, so it gives a falsely low reading.
2) What did you do at 6.30 am (if anything) to cause it to start falling?

 

[helli]

The other thing I would add is to draw no conclusions from the results on the first day as they may be affected by "insertion trauma" - the affect of sticking an alien object in your arm can be some random looking results for the first day. This is not experienced my everyone but as it is your first Libre, you do not know if you do or not.

 

[Emilymay]

It’s difficult to draw conclusions from one night's readings. I think you need to see if the pattern is repeated over subsequent nights.
Two initial observations, though.
1) The big dip and rise, between 4.30 and 5am could be a 'compression low' where you lie on the sensor and squish the interstitial fluid that it relies on to read, so it gives a falsely low reading.
2) What did you do at 6.30 am (if anything) to cause it to start falling?

It rose even more slightly when I started walking to work (left at 6:30) and then 06:54 it started creeping down again when I sat down.

 

[Emilymay]

The other thing I would add is to draw no conclusions from the results on the first day as they may be affected by "insertion trauma" - the affect of sticking an alien object in your arm can be some random looking results for the first day. This is not experienced my everyone but as it is your first Libre, you do not know if you do or not.

Thank you. I know I shouldn’t be reading into it too much on my first date. All these new numbers are so interesting though, was doing finger prick method before.

 

[rebrascora]

I agree the sharp dip is almost certainly a compression low and then it looks like you may have a bit of Dawn Phenomenon/Foot on the Floor Syndrome which took you up to just under 10 (those readings above 10 were almost certainly the Libre algorithm over predicting the rise). I am guessing the walk to work brought them down, but it takes a while for that to kick in so it probably looked like sitting down brought your levels down when it was likely the delayed effect of walking which started to reduce them. I find that I need about 40 mins of brisk walking to be effective at reducing levels for me.
I assume there was no breakfast consumed during this time? What about a cup of tea or coffee with milk. I find a coffee with milk will raise me 1-2mmols in the morning.

 

[Emilymay]

I agree the sharp dip is almost certainly a compression low and then it looks like you may have a bit of Dawn Phenomenon/Foot on the Floor Syndrome which took you up to just under 10 (those readings above 10 were almost certainly the Libre algorithm over predicting the rise). I am guessing the walk to work brought them down, but it takes a while for that to kick in so it probably looked like sitting down brought your levels down when it was likely the delayed effect of walking which started to reduce them. I find that I need about 40 mins of brisk walking to be effective at reducing levels for me.
I assume there was no breakfast consumed during this time? What about a cup of tea or coffee with milk. I find a coffee with milk will raise me 1-2mmols in the morning.

I did think the 11 readings were a bit drastic considering how quickly they came back down. The readings rising and falling do time with the walk to the bus, sitting on the bus and then failing after walking from the bus to the work.
No, no breakfast was consumed or drinks. I water fast from dinner (about 7:30ish) until 1pm the next day.

 

[Proud to be erratic]

I, for what little it's worth, agree with the previous comments.

Too soon after 1st fitting, need 2 or 3 days to really see a pattern and these first few hours/days with CGM are truly fascinating (mesmerising) after nothing but finger prick readings!

It takes a while for anyone to mentally adjust to the sudden overload of data, time (weeks at least) to get used to the sensitivity of the readings and spot when they are about right or blatantly wrong; if apparently wrong it takes a determined interruption to whatever you are doing to dig out the lance and meter and clarify what an fp is saying! And from that it takes mental effort to not then become complacent and assume its blatantly wrong (briefly) then not bother to fp and check.

Or time to get used to the idea that your interstitial blood truly does bob up and down, sometimes so quickly that a momentary screen figure doesn't finally appear on the Libre daily graph (perhaps because the relatively complex algorithms are smoothing out bumpy interstitial readings with the interpretation into actual BG.

Plus we are so easily seduced by numbers displayed to one decimal point into believing because they are displayed to that accuracy on an accredited medical device - they must be that accurate!! But they aren't. The devices (meters or CGM sensors) cost pennies to manufacture and sell for modest pounds because of profits being made by every agency in the supply chain; this of course is very normal for anything manufactured. But these are mass produced devices which have accuracy limitations. So it takes time (and mental effort initially) to remind yourself the nos are about right rather than exactly right and the most important thing are the trend arrows. Then learning when a downward trend is momentary or a clear warning that your BG is unexpectedly truly falling.

Anyway, enjoy the experience, the learning, the fascination @Emilymay and I hope you get great longer term support from your CGM after several months with only finger prick testing. It can be very obsessive at first, but I think that's inevitable and necessary to understand what you are entrusting your personal BG protection to.

 

[Proud to be erratic]

I water fast from dinner (about 7:30ish) until 1pm the next day.

PS @Emilymay, your level of hydration will have a significant bearing on both interstitial and actual blood glucose. Personally I can bring a rising BG back just by drinking lots of water. Keeping well hydrated is one of my defaults for BG management. So I would never knowingly water fast for such a long period.

 

[rebrascora]

As others have said, you can't draw any real conclusions from just one day's results, so you need to look for trends.
It is worth mentioning that eating something as soon as you wake up can stop DP for some people. The act of food hitting the stomach should trigger the liver to stop releasing that morning surge of glucose which is supposed to give you energy until you have your first meal of the day. It is believed to stem back to our ancestors needing to hunt or forage for breakfast and therefore energy was needed otherwise they would not be successful hunting and potentially end up starving, so the liver pumps out extra glucose to provide the fuel to hunt breakfast and eating shuts it down because it is no longer needed. Of course our modern day life doesn't need that glucose surge just to walk into the kitchen and open the fridge and we have plenty of stored fuel in our bodies to keep us ticking over for many hours and indeed many days in some cases, but those of us with diabetes don't produce enough insulin to deal with that glucose for whatever reason and so our levels rise. Eating a small low carb snack can sometimes help to stop the rise by signalling to the liver that we have food and that extra glucose is no longer needed or the other option is to go out for a run or long walk and the muscles will then sort of suck it out of the blood.

What I am saying is that if you see this regular rise on a morning and want to experiment with trying to stop it, try eating a few nuts or a chunk of cheese or something like that as soon as you wake up instead of fasting and try that for a few days and see if that helps, or try walking a bit further to the next bus stop etc. if you are able.

@Proud to be erratic I believe water fasting is just drinking water whilst you fast from anything else rather than forgoing water.

 

[helli]

Or time to get used to the idea that your interstitial blood truly does bob up and down, sometimes so quickly that a momentary screen figure doesn't finally appear on the Libre daily graph (perhaps because the relatively complex algorithms are smoothing out bumpy interstitial readings with the interpretation into actual BG.

Or that the ISR to BG conversion algorithm is predicting the current value due to the delay in ISR. Then the prediction is overwritten when it "caches up" because the BG trend changed direction.

 

[rebrascora]

Or that the ISR to BG conversion algorithm is predicting the current value due to the delay in ISR. Then the prediction is overwritten when it "caches up" because the BG trend changed direction.

That is certainly the way I see it rather than interstitial fluid actually varying a lot more and the algorithm dampening it down.
I believe those higher levels as overpredictions by the algorithm extrapolating to try to overcome the lag between interstitial and blood rather than actual values of interstitial fluid which are then smoothed out.

 

[Proud to be erratic]

I think, in truth, that is a more accurate way of seeing it. My explanation is too simplistic. But our final perception is that we see a lot of variability and apparent BG movement that should not alarm us. The tricky part for me, with my peculiarly brittle form of D, is deciding is an abrupt downward change a temporary blip or should I be grabbing a future hypo response snack. If I only had £5 for each time I've made a bad call ........ .

 

[Docb]

The only ways that you guys can actually know how the libre code works are if Abbot tell you or if you have the skills to hack the app. I doubt either of those things are likely to happen! 😉