Acromegaly and Other High Dose Conditions: What We Know
What is Acromegaly:
Acromegaly is long-term excessive secretion of growth hormone (GH) from a tumor in the pituitary gland in the brain. In cats, these tumors grow slowly and may be present for a very long time before you notice any changes in your cat. The medical term for acromegaly is hypersomatotropism. The excess growth hormone causes the liver to make another hormone called Insulin-Like Growth Factor -1 (IGF-1). It's this hormone that causes the problems seen in acromegalic cats, such as diabetes.
How Common is Acromegaly in Cats?
In a lecture by Dr. Lunn from Colorado State University at the 2011 ACVIM Forum Proceeding, she stated:
Feline acromegaly has historically been regarded as a rare condition, however recent findings suggest that it may be significantly under diagnosed. In a study of 184 diabetic cats, 59 had markedly increased IGF-1 concentrations, and acromegaly was confirmed in 17 of 18 cats that were examined by computerized tomography (CT), magnetic resonance imaging (MRI), or necropsy. These findings have suggested that any cat with clinical features of acromegaly including insulin resistance, should be screened for this disorder.
At the same forum, Dr. Niessan from London, UK stated:
“Feline acromegaly is now being recognized as an important cause of feline DM, largely as a result of two remarkable prevalance studies. Both these studies suggested that feline acromegaly occurs in a significant proportion of diabetic cats with estimates ranging from 1 in 3 to 1 in 4. Even when adhering to the more conservative estimate, this has justified the initiation of several studies on various aspects of this endocrinopathy, including more careful evaluation of etiology, clinical presentation, and management aspects.”
How do we spot a potential acromegalic cat? Questions we ask.
*Cats are normally flagged up as potentially not being 'normal diabetics' when they are getting higher than normal doses of insulin and/or it's proven difficult to get control over their BGs.
*Just like a 'normal' diabetic cat we think/ask the same questions of a cat’s mom/dad before we think of acromegaly – basics such as appropriate diet, right insulin and doses, and hometesting need to be sorted out first. For example:
1) How long has your cat been on insulin?
2) At what insulin dose did you start?
3) How was the insulin increased and by how much, and over how long a period of time?
4) How did you determine that an increase was needed?
5) Are you home testing now, and if so, have you kept a record?
6) What food are you feeding?
*Once the more common causes of having a cat on high insulin doses have been dealt with, for example dry food, too fast dose rises, infection, etc., - then we start thinking that something else might be going on.
*Acromegalic cats typically have certain patterns or issues going on with them that act as 'red flags' to point us towards thinking 'acromegaly'. It's a collection of these issues that just aren't 'right'. We then start asking more hi-dose specific quesitons such as:
7) Have you noticed changes in the way your cat breathes? Any changes in their eye sight?
8) Have you noticed any behavioral changes in your cat? For example, appearing to be in pain, avoiding bright light.
9) Have you noticed any physical changes in your cat's appearance?
10) Has your cat had a tendency to gain weight despite no increases in amount of food you are feeding?
Link to have blood sent for IGF-1 testing:
For the USA and Canada – costs vary depending where you live:
MSU Veterinary Diagnostic Laboratory
Search for code 20005
UK - (no longer free, but can be requested at): https://www.rvc.ac.uk/pathology-and...s/diagnostic-laboratories#panel-diabetic-cats
As of January 25, 2024, MSU has changed the type of assay (now chemiluminescent or CLIA) used to test for IGF-1, and at the same time changed the units used from nmol/L to ng/mL, which is now consistent with testing done in the UK at the Royal Veterinary Clinic.
Current ranges for the US - a result of >916 is considered + for acromegaly; in Great Britain a result of >1000 using the radioimmunoassay is considered + for acromegaly, with >700 as the gray zone. We have seen results in Europe using a chemiluminescent assay with >650 as + for acromegaly.
Before January 25, 2024, in the US – a result > 92 was considered + for acromegaly; in Great Britain a result > 1000 was positive.
Link to have blood sent for Growth Hormone test (Newest blood test being asked for by Colorado State University for documentation of acromegaly):
*currently this test is unavailable - we will update with further news*
Once diagnosed:
It is IMPORTANT to remember – there is nothing weird or wonderful about how a high dose cat's diabetes is managed. However, we do recommend that one should NOT 'go it alone' without the support of the FDMB and/or the vet in caring for these cats. Although their care follows basic common sense it also tends to involve more insulin.
Some falicies about acrocats:
*They never get DKA – NOT TRUE! Several of our acrokitties have been quite ill with DKA – Jennifer’s Spunky, Dale Ann’s Snuggle’s are just a couple of them.
*They ALWAYS have large heads, feet, bodies. – NOT TRUE – oftentimes the physical features aren’t seen until much later in the disease process!
*Acromegalic cats won't suffer from hypoglycemia. No, acromegalic cat's BGs can drop to extremely low levels if the IGF-1 levels in their bodys reduce, their own insulin is working and we give them 'extra' insulin.
And if we can't get a diagnosis for a hi-dose cat?
Ultimately if a cat is on the correct diet and insulin regimen, the owner is hometesting, there are no other factors that could be causing raised BGs (infection, pain) and all lab tests have come back negative (IGF-1, Cushings, IAA etc) then it can be a case that the cat is just a hi-dose cat, plain and simple. If that's the case then giving the insulin and doses the cat needs, however large to gain control of the BGs is what needs to be done.
Some of our acrocat’s stories:
Beth and Pickles, Stephanie and Pheobe, and Lara and Paddy: Insuvet PZI cases
Carolynn and Fletcher: http://www.blogster.com/carolynn/
Patti and Merlin: Merlin http://www.blogster.com/pattiandjoe/1173654980
Further Information:
*Feline Acromegaly: An Underdiagnosed Endocrinopathy?
Journal of Veterinary Medicine
https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1939-1676.2007.tb03041.x
*Feline Acromegaly: An essential differential diagnosis for the difficult diabetic
Feline acromegaly: an essential differential diagnosis for the difficult diabetic - PubMed
Acrotracker link: https://docs.google.com/spreadsheet...Gt3RUpYWmRoR2Q5SWRSV1dUUElwUlE&hl=en_US#gid=0
Cats with Insulin Auto Antibodies (IAA)
Insulin antibodies
When insulin is injected into a diabetic cat, the body views it as a foreign substance and the immune system sets out to destroy the "invader" insulin, just as it would destroy cold and flu viruses. When this happens to injected insulin - most of it never reaches the bloodstream thus being unable to control blood glucose. Insulin doses may be increased but the immune system only goes into higher gear and continues to effectively destroy any additional injected insulin. Over time this becomes officially known as insulin resistance.
Sharyn and Fiona states: One article on humans suggests that changing insulin doesn't work. IAA is supposed to be self-limiting, meaning it goes away at some point. (See article link below) “We have a couple of anecdotal reports of kitties who, by continuing to raise the insulin doses, were able to overwhelm the antibodies, eventually lower the insulin doses and gain control of the BG’s.”
Currently 10/09 Sandy and Black Kitty seem to have done just that. At one point Black Kitty was needing 27 units of Lantus insulin/day. He is now OTJ. GREAT JOB BK!!!!
Link to have blood sent for IAA testing:
MSU Veterinary Diagnostic Laboratory
Search for code 20031
A result > 20% is considered positive for IAA.
Further Information:
*Extreme insulin resistance (IAA)
diabetes FAQ: treatment (part 3 of 5)Section - Extreme insulin resistance
*Beta cell and insulin antibodies in treated and untreated diabetic cats
Beta cell and insulin antibodies in treated and untreated diabetic cats - PubMed
Cushing's disease:
The Feline Facets of Cushing's Disease (March 2018)
http://www.cat-health-guide.org/felinecushingsdisease.html
http://www.cat-lovers-only.com/cushings-disease-in-cats.html
Cushing’s disease is caused by a tumor of either the pituitary or adrenal glands, causing the production of excess cortisol. Cortisol is a naturally-occurring chemical in the body, which helps the body respond to stress such as infection or pain. With Cushing’s disease, however, the body continues producing cortisol even when the stressor has been removed. This causes a number of problems one of which is insulin resistant diabetes.
One particular symptom that helps differentiate this disease from acromegaly so quickly is that Cushing’s causes very thin fragile skin that may tear easily and/or not heal well. Females are most often the target.
This document was written in honor and loving memory of ALL hi dose kitties. For despite all the difficulties they face - they continue to teach their moms/dads daily, purr the loudest, and give us such unconditional love!
Sources:
Carolynn Fletcher (GA) & Robbie (GA). “Acromegaly and Other High Dose Conditions: What We Know.” Feline Diabetes Message Board, 30 Dec. 2009, https://felinediabetes.com/FDMB/threads/acromegaly-and-other-high-dose-conditions-what-we-know.375/
What is Acromegaly:
Acromegaly is long-term excessive secretion of growth hormone (GH) from a tumor in the pituitary gland in the brain. In cats, these tumors grow slowly and may be present for a very long time before you notice any changes in your cat. The medical term for acromegaly is hypersomatotropism. The excess growth hormone causes the liver to make another hormone called Insulin-Like Growth Factor -1 (IGF-1). It's this hormone that causes the problems seen in acromegalic cats, such as diabetes.
How Common is Acromegaly in Cats?
In a lecture by Dr. Lunn from Colorado State University at the 2011 ACVIM Forum Proceeding, she stated:
Feline acromegaly has historically been regarded as a rare condition, however recent findings suggest that it may be significantly under diagnosed. In a study of 184 diabetic cats, 59 had markedly increased IGF-1 concentrations, and acromegaly was confirmed in 17 of 18 cats that were examined by computerized tomography (CT), magnetic resonance imaging (MRI), or necropsy. These findings have suggested that any cat with clinical features of acromegaly including insulin resistance, should be screened for this disorder.
At the same forum, Dr. Niessan from London, UK stated:
“Feline acromegaly is now being recognized as an important cause of feline DM, largely as a result of two remarkable prevalance studies. Both these studies suggested that feline acromegaly occurs in a significant proportion of diabetic cats with estimates ranging from 1 in 3 to 1 in 4. Even when adhering to the more conservative estimate, this has justified the initiation of several studies on various aspects of this endocrinopathy, including more careful evaluation of etiology, clinical presentation, and management aspects.”
How do we spot a potential acromegalic cat? Questions we ask.
*Cats are normally flagged up as potentially not being 'normal diabetics' when they are getting higher than normal doses of insulin and/or it's proven difficult to get control over their BGs.
*Just like a 'normal' diabetic cat we think/ask the same questions of a cat’s mom/dad before we think of acromegaly – basics such as appropriate diet, right insulin and doses, and hometesting need to be sorted out first. For example:
1) How long has your cat been on insulin?
2) At what insulin dose did you start?
3) How was the insulin increased and by how much, and over how long a period of time?
4) How did you determine that an increase was needed?
5) Are you home testing now, and if so, have you kept a record?
6) What food are you feeding?
*Once the more common causes of having a cat on high insulin doses have been dealt with, for example dry food, too fast dose rises, infection, etc., - then we start thinking that something else might be going on.
*Acromegalic cats typically have certain patterns or issues going on with them that act as 'red flags' to point us towards thinking 'acromegaly'. It's a collection of these issues that just aren't 'right'. We then start asking more hi-dose specific quesitons such as:
7) Have you noticed changes in the way your cat breathes? Any changes in their eye sight?
8) Have you noticed any behavioral changes in your cat? For example, appearing to be in pain, avoiding bright light.
9) Have you noticed any physical changes in your cat's appearance?
10) Has your cat had a tendency to gain weight despite no increases in amount of food you are feeding?
Link to have blood sent for IGF-1 testing:
For the USA and Canada – costs vary depending where you live:
MSU Veterinary Diagnostic Laboratory
Search for code 20005
UK - (no longer free, but can be requested at): https://www.rvc.ac.uk/pathology-and...s/diagnostic-laboratories#panel-diabetic-cats
As of January 25, 2024, MSU has changed the type of assay (now chemiluminescent or CLIA) used to test for IGF-1, and at the same time changed the units used from nmol/L to ng/mL, which is now consistent with testing done in the UK at the Royal Veterinary Clinic.
Current ranges for the US - a result of >916 is considered + for acromegaly; in Great Britain a result of >1000 using the radioimmunoassay is considered + for acromegaly, with >700 as the gray zone. We have seen results in Europe using a chemiluminescent assay with >650 as + for acromegaly.
Before January 25, 2024, in the US – a result > 92 was considered + for acromegaly; in Great Britain a result > 1000 was positive.
Link to have blood sent for Growth Hormone test (Newest blood test being asked for by Colorado State University for documentation of acromegaly):
*currently this test is unavailable - we will update with further news*
Once diagnosed:
It is IMPORTANT to remember – there is nothing weird or wonderful about how a high dose cat's diabetes is managed. However, we do recommend that one should NOT 'go it alone' without the support of the FDMB and/or the vet in caring for these cats. Although their care follows basic common sense it also tends to involve more insulin.
Some falicies about acrocats:
*They never get DKA – NOT TRUE! Several of our acrokitties have been quite ill with DKA – Jennifer’s Spunky, Dale Ann’s Snuggle’s are just a couple of them.
*They ALWAYS have large heads, feet, bodies. – NOT TRUE – oftentimes the physical features aren’t seen until much later in the disease process!
*Acromegalic cats won't suffer from hypoglycemia. No, acromegalic cat's BGs can drop to extremely low levels if the IGF-1 levels in their bodys reduce, their own insulin is working and we give them 'extra' insulin.
And if we can't get a diagnosis for a hi-dose cat?
Ultimately if a cat is on the correct diet and insulin regimen, the owner is hometesting, there are no other factors that could be causing raised BGs (infection, pain) and all lab tests have come back negative (IGF-1, Cushings, IAA etc) then it can be a case that the cat is just a hi-dose cat, plain and simple. If that's the case then giving the insulin and doses the cat needs, however large to gain control of the BGs is what needs to be done.
Some of our acrocat’s stories:
Beth and Pickles, Stephanie and Pheobe, and Lara and Paddy: Insuvet PZI cases
Carolynn and Fletcher: http://www.blogster.com/carolynn/
Patti and Merlin: Merlin http://www.blogster.com/pattiandjoe/1173654980
Further Information:
*Feline Acromegaly: An Underdiagnosed Endocrinopathy?
Journal of Veterinary Medicine
https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1939-1676.2007.tb03041.x
*Feline Acromegaly: An essential differential diagnosis for the difficult diabetic
Feline acromegaly: an essential differential diagnosis for the difficult diabetic - PubMed
Acrotracker link: https://docs.google.com/spreadsheet...Gt3RUpYWmRoR2Q5SWRSV1dUUElwUlE&hl=en_US#gid=0
Cats with Insulin Auto Antibodies (IAA)
Insulin antibodies
When insulin is injected into a diabetic cat, the body views it as a foreign substance and the immune system sets out to destroy the "invader" insulin, just as it would destroy cold and flu viruses. When this happens to injected insulin - most of it never reaches the bloodstream thus being unable to control blood glucose. Insulin doses may be increased but the immune system only goes into higher gear and continues to effectively destroy any additional injected insulin. Over time this becomes officially known as insulin resistance.
Sharyn and Fiona states: One article on humans suggests that changing insulin doesn't work. IAA is supposed to be self-limiting, meaning it goes away at some point. (See article link below) “We have a couple of anecdotal reports of kitties who, by continuing to raise the insulin doses, were able to overwhelm the antibodies, eventually lower the insulin doses and gain control of the BG’s.”
Currently 10/09 Sandy and Black Kitty seem to have done just that. At one point Black Kitty was needing 27 units of Lantus insulin/day. He is now OTJ. GREAT JOB BK!!!!
Link to have blood sent for IAA testing:
MSU Veterinary Diagnostic Laboratory
Search for code 20031
A result > 20% is considered positive for IAA.
Further Information:
*Extreme insulin resistance (IAA)
diabetes FAQ: treatment (part 3 of 5)Section - Extreme insulin resistance
*Beta cell and insulin antibodies in treated and untreated diabetic cats
Beta cell and insulin antibodies in treated and untreated diabetic cats - PubMed
Cushing's disease:
The Feline Facets of Cushing's Disease (March 2018)
http://www.cat-health-guide.org/felinecushingsdisease.html
http://www.cat-lovers-only.com/cushings-disease-in-cats.html
Cushing’s disease is caused by a tumor of either the pituitary or adrenal glands, causing the production of excess cortisol. Cortisol is a naturally-occurring chemical in the body, which helps the body respond to stress such as infection or pain. With Cushing’s disease, however, the body continues producing cortisol even when the stressor has been removed. This causes a number of problems one of which is insulin resistant diabetes.
One particular symptom that helps differentiate this disease from acromegaly so quickly is that Cushing’s causes very thin fragile skin that may tear easily and/or not heal well. Females are most often the target.
This document was written in honor and loving memory of ALL hi dose kitties. For despite all the difficulties they face - they continue to teach their moms/dads daily, purr the loudest, and give us such unconditional love!
Sources:
Carolynn Fletcher (GA) & Robbie (GA). “Acromegaly and Other High Dose Conditions: What We Know.” Feline Diabetes Message Board, 30 Dec. 2009, https://felinediabetes.com/FDMB/threads/acromegaly-and-other-high-dose-conditions-what-we-know.375/