Please help - 14 day Lantus graph. Wild swings in sugar?

Folks, we have been having a lot of trouble regulating Astrophe's sugar levels with Lantus, and finally, after 6 months of struggle, we decided to get a Calibri Freestyle Libre continuous sensor to figure out what's going on.

The sensor takes a reading every 10 minutes, so we have a lot of data. We also verified the sensor with prick testing. The sensor has yielded a lot of rich data over two weeks that we are at a loss to interpret.

Please see attached graphs (please ignore the spreadsheet for now)

(1) A 14 day graph of blood sugar, doses every 12 hours, with the dose given in red
(2) Zoomed views for 2 days

Please note:

(1) The vertical axis represents the blood sugar reading at any given time (so for example, the nadir on 1/28 midnight was 80)
(2) The horizontal axis is days (each grid division is 12 hours)
(3) The red numbers is each Lantus dose in units given.

Observations:

(1) Lantus seems to not be lasting long enough. You can see in the graph that the nadir seems to happen in about 4 hours, and by 8 hours or so the blood sugar is already back to the pre-shot levels.

(2) This results in remarkable highs and lows - I had thought Lantus would allow for a smoother graph due to depot action? Could folks chime in here?

(3) In the second week, Lantus also seemed to be losing its efficacy. Nadirs seemed higher, and even increasing the dose (from 3.5 to 4) wasn't bringing them down. The first week nadirs were below 100 with doses of 3.0. In the second week, nadirs are higher (200+) even with increased doses of 3.75 or more.


Questions:

(1) Is this the blood sugar curve we should expect with Lantus? Or is there something wrong?
(2) Since nadirs are at 4 hours, and in 8 hours you're back to pre-shot values, should we consider three times a day dosing?
(3) What can we do to reduce the large peaks and drops?
(4) Sometimes a dose results in a drop of 350 (e.g. 1/30 PM) - but sometimes only a drop of 150 or less (e.g. 2/3 AM)
(5) Any thoughts on why nadirs are rising even with increased doses? Insulin resistance?
(6) Should we consider a different insulin?
(7) Any other advice? We still have high sugar levels and there is sugar in the urine.

We are at a loss. Would be grateful for folks advice and thoughts.

Thank you so much!

 

I can't understand the charts. What are the red numbers at the peaks?

I looked at your ss although there is limited data for 2019. It appears you are dosing based on the preshot numbers. Lantus is based on how low kitty goes during a 12 hr cycle. And it looks like your holding the dose to long.

You might want to read the sticky notes on how lantus works. After you give shot, glucose will go down until it starts to wear off and glucoses start to rise again until next shot. This is normal. Now every cat will have different times this happens. With lantus the low is usually 5-7 hrs after shot. This number once you get it determines the dose. But you don't necessarily change dose for very next shot (unless it was very low). Some cats will also go high if they have a glucose that they are not use to this is called a bounce. Again that's normal.

Please review the data at the main menu and how lantus works. Once you understand it, you might be able to your kitty better.

 

Thanks for the note!

The lines represents the blood sugar plotted against time. It is measured every 10 minutes, using the sensor, over 14 days. It has also been double checked with pricks and strips.

Specifically:

(1) The vertical axis represents the blood sugar reading at any given time (so for example, the nadir on 1/28 midnight was 80)
(2) The horizontal axis is days (each grid division is 12 hours)
(3) The red numbers is each Lantus dose in units given.

There are three attached graphs in the post:

(a) blood sugar over 14 days
(b) a zoomed view over the first few days
(c) a zoomed view over the last few days.

I've read the sticky and numerous other material over the months we have been struggling with this and understand the depot and the dose / bounce effects.

I'm struggling to reconcile that information with what we're actually seeing with the data. Since we now have Astrophe's exact blood sugar readings - taken every 10 minutes over the last two weeks - the resulting graph seems quite different from what I'd expect from my understanding of how Lantus would ideally work, hence my questions above.

Would love any insights folks might have on the graph or on my questions above.

Also, if folks are interested in our sensor experience, would be happy to share.

Thanks once again!

 

As Paula mentioned above, we are used to reading spreadsheets in our format. The colour coding also helps us figure out what is happening. We have had a couple people who are using the Libre transfer those numbers to the spreadsheet, but I'm not sure how they did it.

People here use one of two dosing methods, either the Tight Regulation protocol (provided an all wet food or raw low carb diet) or Start Low Go Slow method. What food is Astrophe getting now? With both dosing methods, we keep the same dose for at least six cycles, unless a reduction is earned. The depot can take six cycles to get established, so that after those six cycles at the same dose, you know how low that dose can take the cat. We make dose changes based on the lows or the nadirs. Depending on which dosing method you wanted to follow, Apostrophe may have earned a reduction by going below 90 (SLGS) or is not (TR).

I will try to answer your questions above:

Yes it looks like I would expect, a normal Lantus cycle is a curve, with higher numbers at preshots and dipping down to lower numbers somewhere in the middle. Bounces or reduced shot can impact the curve. The preshots are seldom the same.

I don't see the 8 hour duration. Too low a dose can also lower the duration. With the data and experience you have I would NOT shoot three times a day, but rather try to use one of our dosing methods to get to a good dose first. We gave had 1 person in about the last 5 years here try the 8 hour shots. She was very experienced and still got little sleep. I think it's too early to consider 8 hour dosing.

Follow the dosing methods here and get to a better dose. Be patient, cats take as long as they take to stop bouncing. You can try to a good dose where she spends more time in normal numbers. Also, with cats that really take steep drops (which can also lead to bouncing), you can try feeding the curve.

Not sure what the question is, sounds like a follow on to the previous one. Best answer is "because they are cats". Insulin is a hormone not a drug, so you may not see consistency. Look at some of the spreadsheets from other cats here. They are a great way to learn.

You aren't being consistent with dosing, so you can't say that are rising. It is possible you are fighting some glucose toxicity, which is a form of insulin resistance. But it's hard for me to say that looking at the graph.

I would try following one of our dosing methods first and give Lantus a fair trial. Switching to a new insulin and dosing randomly won't help.

I will be a broken record. Pick a dosing method and follow it to better numbers. I agree that he is spending the majority of his time above renal threshold. This looks like it might be too little insulin, but can't tell for sure in that data format.

 

Thank you so much for taking the time to reply. For context, we have been trying the SSGS method for 5 months or so without managing to get consistent low numbers - we would always be above the renal threshold. That's why we finally decided to get the sensor, and we tried to adjust a little more aggressively while we had the sensor on (because we knew it would stop working in 14 days and it was a devil to get on)

Couple of quick points:

(1) First, I have manually updated the spreadsheet with the sensor numbers for your convenience. (Takes some time to manually copy each reading, so my apologies for the delay) Astrophe's spreadsheet: https://docs.google.com/spreadsheets/d/e/2PACX-1vSTSHp1zpoNZsJMDrOag_75xH2CsAAZRm28-TwZvyTVcJCEgTjmyhj1Ywu8E1sZkiyKHokyUtqIbmJz/pu . Hope this helps!




(2) >>can't say you're rising. It is possible you are fighting some glucose toxicity, which is a form of insulin resistance. But it's hard for me to say that looking at the graph.

Thank you. My observation was just based on the fact that when we dosed at 3.25 for roughly 9 days (see sheet) the nadirs seemed lower than when we raised the dose to 3.75. You can see this difference in the two graphs below, which I find puzzling.

JAN 28 - JAN 30: (Dose of 3.25, but nadirs of 80, 150)



FEB 9 to FEB 11 - (Higher dose of 3.75, but nadirs of 250+)



Lastly, the sensor is off now. We are back to the usual SSGS method with a current dose of 4. Nadirs at 4 hours are around 210.
We'll re-adjust after 4 days.

Thanks once again!

 

Thanks for updating the spreadsheet. I find that much easier to read and understand what was happening. I see you were dosing differently in the AM vs the PM. That can cause some wonky numbers. The SLGS method says to reduce if you see numbers below 90, which you did at the beginning of the two weeks of the Libre, and were dosing 3.25/3.0 units. I would have reduced back to 3.0 units and done that dose both AM and PM. SLGS says to dose the same dose AM and PM, for seven days, unless you see a number under 90, in which case you immediately reduce by 0.25 units.

 

I use Levemir for my two insulin-dependent cats. I do make slight dose adjustments when I get lower than expected PSs. Knowing it is a depot insulin I consider it would really mess up the depot to skip a dose.
I have asked my vet to insert a Libre in my two cats (at different times) to better understand what is happening.

 

Wow, that's a lotta data! Good luck riding the roller coaster. You are in those scary pinks, but I will warn you from experience that if you increase dosing using a protocol like Roomp & Rand, you may hit a number where something "breaks" and you start having to lower the dose VERY quickly. We only tested 4 times a day unless we were hitting super-lows (AKA, 50's).

I agree to keep the dose stable AM/PM unless you have a reason to shoot less (AKA, BG numbers drop 300 points quickly, which happened to us). Remember that Lantus is a depot drug so you are only averaging up or down with each dose. Thus, if/when you hit the magic break point, it can get really hairy to back off the dose quickly.

Looking forward to seeing more yellows and blues soon!

 

Just wondering how you managed 14 days.
Where was the sensor inserted?
Was tissue glue used?
Was there a protective collar over the sensor?
Any other actions taken?

 

Looking at your spreadsheet, one of the complicating factors is, as Wendy mentioned, not following consistent dosing at AM and PM. Every time you change a dose, you destabilize the insulin depot. Thus, if you are giving a different amount of insulin at each shot time, the depot never stabilizes and numbers won't do what you want them to do. Between the different doses and bouncing, you're seeing numbers you don't like.

At this point, if you're going to follow SLGS, continue at the 3.75u dose for a total of 7 days unless Astrophe's numbers drop below 90. If they drop below 90, lower the dose to 3.5u.

Given the amount of data you have, you could easily follow TR.

 

In re sensor:

Our first application attempt failed as the cat would flinch when the applicator made a loud "click noise". The second applied, but gave an error code. The third was successful.

A liberal amount of vetbond adhesive helps, as does a very close shave on the application site. We had a piece of cloth that we initially used around the sensor but took it off after a day since Astrophe wasn't meaning with it.

Getting it installed is indeed an ordeal. That's why we wanted to make as much of the data we did manage to get as we could.

 

In re dosing:

We were doing 3.25/3 AM/PM, but shifted to a consistent AM/PM dose.

The sensor has expired now so doing TR is no longer possible. We did discover that his nadir's are at 4 hours.

He is at 4.5 units now, AM and PM. Yet even at that dose his nadir's are 250+. I don't understand and am very discouraged.

 

I don't see any data on the spreadsheet past the time the Libre was removed. The data from the Libre does not support the suggestion that his nadir was at +4. Nadirs can and do move around.

You need to test sufficiently according to SLGS to increase the dose safely. It's possible you have increased too much, or not, hard to tell with data I don't see. When are you testing now? At home? And don't worry about the size of dose. Cat's need however much insulin they need and it widely varies by cat. Neko first saw green at about 3.5 units, but didn't earn her first reduction until 8.75 units.

 

Pink numbers are very frustrating, but that next dosecrease may be the key.

Are you feeding zero carb or near zero carb food? We switched to Young Again on Day 27 or so, and we wonder how much that had an impact to allow the insulin to finally break through and do its job. Of course, ECID.

Keep on keepin' on!

P.S. Our breakthrough dose was at 5 (we had a single dose of 5.5, but backed off after he threw a string of greens, starting w/ a morning number of 369 followed by a scary +6 of 31 - yikes!). It took us 12 days of 4.75 going to 4U doses after that, and he decided to never throw another yellow again. Rapid dose decreases were required after that, due to super low BG numbers, down to .75/1U within about a week.