Elevated insulin growth factor and “highly abnormal” BNP/SNAP

We saw a new vet last week who did a thorough examination of Chuck and extensive bloodwork. She was concerned he’s at 8 units of Lantus and after receiving ONE BG of 169 in office she asked me to reduce him to 6 units because she said he’s likely experiencing low blood sugar and rebounds. I pushed back because I’ve done a couple curves and haven’t seen anything below 180 in weeks but eventually gave in. I also bought a new meter because it seemed like mine was inaccurate. I should’ve known better. Within days Chuck was back to 400+ after being steady in the 200s. He was drinking a ton of water and urinating frequently, constantly meowing for food and sleeping more.

I got a call from the vet and she said his fructosamine is 300 (down from 423 last month) but insulin growth factor came back elevated but didn’t provide a number and said he has a highly abnormal BNP/SNAP test. Both of which point to acromegaly? We have an appointment with a cardiologist next week for next steps. In the meantime I brought Chuck back up to his regular dose and kicking myself for listening to the vet. Ugh.

 

The insulin growth factor test points to acromegaly. Try to get the number, as you paid for it. The test result will have a number, you vet just needs to give it to you. Some vets interpret the number incorrectly so that's why it's good to get that number. Acromegaly is caused by a benign tumour in the pituitary that sends out excess growth hormone. A side effect of which can cause heart growth and other heart issues, and the proBNP is a first indicator of that. I'd recommend getting an echocardiogram done by that vet cardiologist. Heart issues can sneak up on you, but can be treated if caught in time. I learned that the hard way with another non diabetic cat.

There are treatments for acromegaly that can help, from radiation therapy (that Neko got), to surgery to remove the pituitary but done in only a few places, to a daily medication called cabergoline. We've even seen a few kitties go into remission on cabergoline.

 

I’m going to follow up for the IGF number tomorrow when the regular vet is back in. I’m a numbers person and I’d like to have it. Chuck has always had a heart murmur but it seems to be getting more severe. For now I’m keeping him calm and we’ll see what the cardiologist says on Tuesday. I’m hoping we can get an echo done the same day, fingers crossed!

 

Let us know how the cardio visit goes. Some murmurs are just an age related thing, which is what Neko had at first. The BNP test might mean something different though.

 

We got back from the cardiologist and Chuck was diagnosed with Hypertrophic obstructive cardiomyopathy (HOCM) Since Chuck’s had a heart murmur his entire life the cardiology vet couldn’t say for sure if his condition was worsening or if it’s always been at this state. He didn’t recommend medication at this time. The vet felt that his condition wouldn’t worsen but we’re going to repeat the echo in 6-9 months. I’m happy we were able to rule out heart disease, all signs point to acromegaly at this point. Going to follow up with our regular vet this week and discuss next steps. Maybe radiation for the acromegaly? I’d rather not risk anesthesia given the murmur but the cardiology vet said they could manage it

 

Good to hear the vet thought no medication needed at this time and that anaesthesia could be done if needed.

As far as treatments go, where are you located (roughly)? Radiation and surgery could require travel, depending where you are. A common treatment many people are using now is the medication called cabergoline. It's a daily or every other day compounded medication that has helped quite a few cats. No travel and a lot cheaper than the other options. We've had 4-5 cats even go OTJ on it. Most cats see a reduction in dose and some of the acro symptoms are reduced. And no anaesthesia required.

 

We’re in Northern NJ. Thanks for all the info! I’d rather meds over travel and anesthesia. The long trip at the vet yesterday had Chuck stressed, even after taking gabapentin. Poor guy. I’m going to talk to his primary vet today. She wants to see a glucose curve and were well overdue

 

One of the Red Banks in New Jersey does SRT (stereotactic radiation therapy), but I'd have to look to see which one. SRT is minimum two days of anaesthesia, if not more.

Good luck with the vet. She might not have heard of cabergoline (not uncommon). I can give you a link to a paper if she needs convincing.

 

Thank you so much!! I will definitely keep you posted. We did a curve yesterday and stayed under 300, that’s something good at least

 

The vet was aligned to raise Chuck’s insulin back up and is still not convinced of acromegaly. She wants an abdominal ultrasound to rule out kidney issues since Chuck had two urine tests come back for high protein. She also wants me to dip test his urine at home for glucose, protein and ketones. Despite Chuck’s glucose being in the 200+ range he’s been negative for glucose in the urine. I’m not sure about the ultrasound…

 

You ever get that IGF-1 number back from the vet? Proteinuria (high protein in urine) is also common in acros. Neko had it too. She was also negative for glucose if under about 220. Ultrasound sounds like a way to spend your money. A better test is the urine protein/creatinine ratio, or UPCR test. I'd get a blood pressure check at the same time as that can cause proteinuria and again is not uncommon in acros. General kidney issues can cause insulin resistance but not to 8 units. Neko got CKD, but was fairly well regulated then on <3 units, that was after SRT.

 

The IGF number is the one thing I forgot to confirm. We did a BUN to creatinine and I remember that being normal. BP at the cardiologist was slightly elevated 160 systolic. I was also concerned about the ultrasound being gimicky…

 

Did you get a number for the urine tests "high protein"?

 

yes. The highest we’ve seen is +2, but his last urinalysis showed 0. They also keep mentioning his urine is very concentrated. He seems to be drinking normally so I’m not sure why that is

 

Lots more about urine protein here. Concentrated urine can show higher protein in urine too as can glucose positive urine. Seems like there's a few reasons for false positives too. Getting a few dipsticks tests at home would provide more data.