Advice on decreasing insulin dose [w/ screenshots]

[leomusmusculus]

Hi all,

Leo is now 1 year 8 months old and 10 lbs. He was per vet recc. brought up to 9u Basaglar/Lantus BID on 6/6/22 (tested negative for IGF-1 at this time). He indicated symptoms of hypo on 8/1 (PM T+3h, BG about 40). The next day 8/2, we went to 8u BID and then on 8/15, we went to 7.5u BID.

We put on Freestyle Libre. Leo gets insulin AM at 7:15am and PM at 8pm. We intervened when he went hypo.
Monday 8/29 - 7.5u BID
Tuesday 8/30 - 7.5u BID
Wednesday 8/31 - 6.5u in the AM. We gave him 5u for PM shot today.

Is this remission? Somogyi? What recommendations do you have regarding tapering his dose?



All help is appreciated. Thanks so much you have all been a great help so far in Leo's journey!

 

[FrostD]

Are you by chance double checking those lows with a handheld meter? The Libres are notorious for reading artificially low at low numbers, it's likely he wasn't actually hypo.

So, a few things:
Lantus is a depot insulin, so at his dose, changing by only 0.5U isn't really going to help you "put on the brakes" if that's what you were trying to do (we call them big chicken shots, or BCSs....typically 25-50% of the normal dose). But if you were just taking standard reductions, then yes you did the right thing by reducing by 0.5U each cycle he went below 50. It just takes a few days for the dose to settle and depot to stabilize.

Remission, by definition, is normal BGs without any insulin. So, I am sorry to say no this is nowhere near remission. You would have to keep stepping the dose down as reductions are earned, all the way down to 0.5U, the 0.25U, 0.1U, then an OTJ trial. That's a long way down for a high dose cat.

There's a few possible explanations from where I sit -
1. You hit a breakthrough dose, where the insulin dose is finally enough to start bringing BG down
OR
2. He been overdosed for some time, and the Libre is now allowing you to see that. Without an up to date spreadsheet, I couldn't say for sure.

Based on the limited data you have, I personally think he is overdosed, by the looks of it quite a bit overdosed. It is not typical to see those huge swings on Lantus on every other cycle, though it can happen.

I'm going to tag @Wendy&Neko for thoughts on dose, but she'll want to see an updated spreads, at least with the recent Libre data entered in.

As for Somogyi, it's never been proven in cats. The theory in humans is now quite old and was based on small sample size, and according to recent papers is under dispute. Somogyi is technically overnight hypoglycemia due to too much insulin, with the following rebound effect. The swings you're seeing are more likely what we call bounces - it's a similar concept but not technically Somogyi - it's a drop that is lower and/or faster than they're used to (it may not actually be hypo, and can occur at any time of day), which causes the liver to panic and dump stored glycogen and counterregulatory hormones in order to spike BG back up.

 

[FrostD]

Don't want to edit post above or the tag will break

Option 3 is that he may have had IAA that is now starting to resolve. Or another underlying condition that you've started treating? I searched through your post history but didn't see anything mentioned.

 

[Diane Tyler's Mom GA]

Your spreadsheet only goes up to 1-22-22

 

[Wendy&Neko]

My first recommendation would be to create a spreadsheet tab for 2022, and get as much of the last two weeks worth of data in it as you can. We are very data driven here, and just seeing a couple days snapshots doesn't help me help you.

Lantus is a depot style insulin. What you shoot one day can influence days after that. Consequently, if you have been shooting 7.5 units long enough to build the depot, it could still impact numbers you see for 2-3 days. Meaning numbers you saw today with 6.5 units could be influenced by the 7.5 unit depot. Typically at Leo's size of dose we'd make changes by 0.5 units at a time. But this depends on the context, which I cannot see without spreadsheet data. Sorry, it's just the way I'm used to looking at blood sugar data in relation to doses given.

 

[leomusmusculus]

Thanks everyone! From what I’m reading, we should continue decreasing insulin by 0.5u each time Leo is BG < 50. I didn’t know that Libre reads artificially low numbers, thank you for that information. If his meter reading is higher at that exact time (say, normal range), do I trust the meter?

Is the dose supposed to be held the same if his BG is in the 50-100 range?

Should we keep him at 7u for now and continue measuring? Or another value? 6u? Hope to get as much out of the Libre as we can.

I can add these Libre values to the spreadsheet. As for another underlying condition, none that we know of.

Thanks for your help!

 

[Wendy&Neko]

If you are following SLGS for dosing, as it says in your signature, the reduction point is if his BG goes below 90, not 50. And you keep the same dose as long as the nadirs (not overall BG) are in the 90-149 range.

As for the Libre, you might want to spot check lower numbers with a hand held BG meter, if you have one. It seems to be only a problem with low numbers, the rest seem to be fine compared to other meters.

I can answer about current dose when the spreadsheet is updated.