Learning more, mainly about cabergoline.

Hi folks!

So I was advised to look over here to see what new treatments might exist for acromegaly. Wanted to learn more, so just to summarize what I know so far.

1.) Surgery; very VERY VERY expensive, pretty effective

2.) Radiation; very expensive, fairly effective

3.) Pasireotide; very expensive, fairly effective, only found one study on it though, but very good effect.

4.) Cabergoline; not as expensive, but mixed evidence. This study from 2020 seemed to suggest that it did nothing https://pubmed.ncbi.nlm.nih.gov/32684121/. Another study found an effect (https://journals.sagepub.com/doi/10.1177/1098612X221074924?icid=int.sj-full-text.citing-articles.1), but it was fairly weak and more importantly there was no control group, which they identify as the biggest limitation of the study.

Does anyone know of any studies that used a control group looking at Cabergoline in Feline Acromegaly? @Wendy&Neko

 

Hi there. Has Sam been diagnosed with acromegaly?

Look at my spreadsheet if you want to know if Cabergoline can lower BG and insulin dose. We went from over 40 units and bad numbers to very low doses and great numbers. I lost him to a different disease. @FrostD has a cat who went into remission on Cabergoline. I believe my boy was going to as well. Other people have had great improvements in BG and insulin dose and symptoms. It’s variable from cat to cat, but so is the surgery, which has dangers and also variable results - depending on whether they”get” the whole tumor. The same can be said for SRT.

 

No, he doesn't have it. Wendy had told me that there were in fact other treatment options other than surgery/radiation/Pasireotide. Just wanted to learn more about it.

 

And why the interest in acromegaly. Sam is on 1 unit and doing well.

 

Oh okay. You just answered my question.

 

Cross posted lol. But are there any other medications other than Cabergoline that anyone would use on here/any evidence for? I would so love to see a study on Cabergoline with a control group. I've been desperately searching scihub, my university account, and google scholar trying to find one. Clearly it has some effect.

 

Oh; found one study which I thought was kinda interesting. Larger sample sizes but it's based off of questionaires by cat owners, not an experiment, lots of sources of bias that would make the obvious interpretation come with a lot of caveats. https://www.vetprofessionals.com/do...ersomatotropism- the owners point of view.pdf

In particular; using pairwise comparisons there is some evidence that cabergoline results in an increased reported quality of life score based on the questionaire when compared to just insulin alone (0.044 was the p value, not significant if you're correcting for pairwise comparisons). They did find though that insulin and hypophysectomy was the most effective treatment option, followed by insulin and radiation, followed by insulin and cabergoline followed by insulin only.

Running theme seems to be a lack of control groups (prospective cohort studies), low sample sizes, or non experimental studies (like this one, where they are looking at essentially population level correlations). I guess this is fairly common in veterinary research where the funding just isn't there.

 

Perhaps most interesting to me is the wide variety of results we see with cabergoline. My cat crashed into remission (see SS July 2021) whereas others take 6+ weeks to see results in terms of BG, if at all. Others report improvement in acro side effects like soft tissue growth, arthritis, etc. It works by blocking the growth hormone uptake; so the tumor is just causing however much growth hormone production and cabergoline can only do so much.

There is only limited evidence (South American study) that it can affect the tumor itself; they also theorized it works best with tumors under a certain size. One of the challenges to studying it is acro cats often come with other comorbidities, so we as caregivers are often hesitant to do anything we deem risky and/or invasive. I would love to have a CT of the tumor before and after cabergoline for my cat, I would love to have imaging if the other acro related issues like skull and soft tissue - but he's had to be resuscitated twice now under anesthesia so it's just not worth it.

I would absolutely love to see it studied more; I think as the veterinary field realizes it's much more common than initially thought it may start getting some more eyes on it.

The human studies may be interesting to you. While humans are obviously not cats, it's usually one of the first things I look at it when I'm in uncharted territory with my cat (take a look at my signature....), just to get an idea of what I'm dealing with and at least make an attempted educated decision.

 

I've actually read a BUNCH of human studies recently on diabetes. I actually just did a post about the three main pathways that cause rebounding after hypoglycaemia (gluconeogenesis, glycogenolysis, and reduced insulin sensitivity caused by adrenaline, glucagon, growth hormone, and cortisol). Gonna keep reading them. I find this stuff fascinating.

There are obvious differences between humans and cats with diabetes though that makes it difficult to extrapolate between species. The main one that I see is that oral medications that work very well in humans that inhibit gluconeogenesis (the production of sugar from non carbohydrate's like lactate) simply do not help in cats. In humans drugs like metformin inhibit the gluconeogenesis that is occurring at too high a level due to increased insulin resistance. But in cats drugs like that do nothing. So clearly the dominant cause of diabetes in cats differs from humans.

In your experience, is it usually all or nothing? Do cats usually either respond really well or not at all to cabergoline? If so that'd be really interesting, because it'd suggest you have two groups of acro cats; ones that respond well and ones that don't. If those groups are well defined then that'd suggest the presence of a mediating variable.

God I wish I was a billionaire. Then I wouldn't have to muse and could actually just spend a couple million to do a study on this lol.

 

Link to your post please?

 

When I said to "have a look" in this forum, I meant to read. So far, the articles you've posted have been linked elsewhere in posts in this forum. Another post you might want to read, that also has articles, is: Acromegaly - the basics

Note, there is nothing like having an acrocat to really learn about this condition. As we say ECID, it's even more so with acros. It is not all or nothing with cabergoline. We've seen 4 cats go OTJ on it, a few where it didn't do much, and most in the middle. In the middle typical means lowered doses, and perhaps even more important, a lessening of the symptoms caused by excess growth hormone and IGF-1. From what I've observed, those on somewhat smaller doses tend to do better, but not always. Amethyst (now GA ) was on it longest of any of the cats here, over 4.5 years.

The link to the South American initial study is here:
Cabergoline as a possible treatment for acrocats: discussion
and their latest paper is here:
New paper on: Cabergoline treatment in cats with diabetes mellitus and hypersomatotropism

 

Oh i did read lots, i just wanted to know if anyone else had any more information that wasn’t already stickied. We all learn in different ways . I learn better by talking to others about a topic. Even if it’s on a forum.

Unfortunately i suspect there’s scant research on this topic, so it doesn’t surprise me at all that on a forum as popular as this that someone at some point would’ve linked/discussed every peer reviewed article on the topic at some point.

Definitely learning a lot though, so thanks for your suggestion! I enjoy a discussion and hearing from others/their experiences. Thanks for sharing yours! I do appreciate it. Best wishes

 

So i’m compiling a list of every study on feline acromegaly published in the last decade (related to treatment). Thank god i still have access to my alumni account! Kinda intrigued by it now.

Hopefully not everything has already been referenced somewhere else!

 

Like Wendy said it's the full range - very few OTJ, some it appears to be minimal/no changes (hard to quantify/qualify internal affects such as soft tissue growth), but most end up somewhere in the middle with some dose reduction + some improvement of other acro effects.

I'm certainly glad I found this forum, especially before his acro diagnosis. Most vets won't test until the dose hits 2U/kg, thankfully we tested sooner and caught it sooner due to all the knowledge here. And since most vets aren't familiar with it, it's a lot of legwork on the CGs. I'm thankful my vet is willing to learn and work with me - he sent me a lot of articles he had access to, was willing to try cabergoline even though at the time the RVC study was the only one out there.

It definitely is "fascinating"...I say that somewhat to gue in cheek because while FD, acro, IAA, etc intrigue me and I love to learn, I'm still taking care of an acro cat and more than likely he will pass from something related to it. For now we seem to be one of the lucky ones, I've seen no visual progress of the disease.

 

I'm glad you modified that to include all studies, not just western literature. There is research from Japan as well. There are also good articles in that Acromegaly the basics post I linked that go back further than 10 years. If you find a link that you cannot find the full article for, let me know. One of our members works at a university that has a well known vet school and has access to those articles too. Some of which I have squirrelled away.

 

I'm mostly able to access them. If my university doesn't have them I just use scihub (has a lot more physics articles than medical articles, but still 99% of the time I can find it).

Can you please PM or link me the Japanese Study? I can't find it.

 

Here is one paper from Japan, I don't think it's the only one. I was intrigued by it because it was of a cat who had two courses of SRT, like Neko did. That's relatively uncommon.

 

Right now Eddie has had two courses of SRT, so you can add him to the uncommon list. Blue on the hand had fractionated radiotherapy (over 3 weeks) and then SRT (only one fraction).
There is an intern at WSU who is now researching and writing a paper on Eddie and Blue, biological brothers with acro...More to come.

 

I know of one or two other cats who have had double SRT at CSU as well. The radiation oncologist there also know of another cat who needed the second SRT, but the caregiver decided not to.