Acromegaly/Insulin resistance at *very* high doses - others experience?

I am interested in other peoples experience with Insulin resistance due to Acromegaly at very high doses.

Hopefully the question will help others on the same path as well as I have done a quite a bit of research.

The cat in question is a 13 year old neutered male and 20 months in from DM diagnosis with a follow up confirming IGF-1 test. BS at diagnosis was around 450 with PU/PD.

Elected not to attempt surgery or radiotherapy as the results are marginal and no nearby center and just treat the DM. UC Davis were negative on surgery and neutral on radiation.

He has been under specialist vet care from experts in the disease and mostly doing ok. Close to normal metabolic panel with a minor heart murmur. He is already beyond the mean survival rates from aggressive treatment. One happy cat and weight stable or increasing. A lot of snoring as expected but still quite active.

The Lantus doses, are getting very high to get any kind of control and have increased progressively as per the usual progression. Currently 35U/BID so 70U a day of Lantus with a nadir around 350. I know this is going to sound impossible for anyone with a cat with simple DM! Confirmed with Abbot Libre CGM and AlphaTRAK 2 with feline calibration. No adverse reactions.

Probably going to need 40U BID/80U a day to get to a 250 BS target.

Does anyone have experience at these very high doses? Specialist vet say he has seen even higher doses (90U) but the caution is fluctuation in the IGF1 as the tumor gets unstable, reducing the insulin resistance, which at this dose would not be good! There is not much data.

Obviously all cats are different but would be very interested in anyone else who has been down this path, especially the instability from parts of the tumor losing blood supply and potential Hypoglycemia.

Thanks!

 

@Wendy&Neko is the person here for Acro and IAA.

@Suzanne & Darcy was at 41 units twice a day plus R insulin. Maybe she can give some insight.

 

Tagging @Howiesmom whose cat got up to 55 units and is now down to 30 on cabergoline. He is quite well regulated. Here is what Howie's blood sugar spreadsheet looks like. Karen's Lily also got to 55 units, very well regulated, and eventually went off of insulin. That is also quite unusual for a cat to go that high then go off of insulin. Here's is Lily's spreadsheet. Sadly Lily passed earlier this year, over 5 years past diagnosis. We have other people with acrocats who post here and the Acromegaly / IAA / Cushings Cats forum. The highest dose I've seen was about 85 units twice a day, but that was a combination of Levemir and R in two different cats. I've seen the spreadsheet of another kitty that needed almost 100 units. Those really high doses are quite unusual. I've only seen two in my time here.

Home testing blood sugars is key to keeping your cat safe. The tumour doesn't go down that fast on it's own that you can't keep up with it if you are monitoring daily. People who have treated their cats (such as my girl's radiation therapy) can see a quicker drop in dose. Using R or Regular insulin in combination with the depot insulin (Lantus or Levemir) gives you some control over the depot when the dose is reduced.

 

I found your post on the Acro forum and responded there! Please continue to ask questions and post info you’re learning too!