Info acromegaly - the basics - hope you will read n like

Discussion in 'Lantus / Basaglar (glargine) and Levemir (detemir)' started by Patti and Merlin, Jun 12, 2011.

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  1. Patti and Merlin

    Patti and Merlin Member

    Dec 28, 2009
    This was a post made by Beth and Pickles back in 2008 when we were FIRST starting to see so many more acromoms/dads. It still holds true today. She wrote a brilliant piece explaining very clearly about acromegaly. I thought it might help people who want to understand this in abit more depth.

    Posted by: Beth & Pickles (Tam GA) (IP Logged)
    Date: August 31, 2008 03:45AM

    With more new owners joining the Acrocat group I think it's important to make sure that everyone understands what Acromegaly actually is. Why we see the things we see in the cats, what's going on to produce the outward signs and thus the reason why we do some things. I've written this as simply as I could so that hopefully everyone can understand. I'm not suggesting that people are unable to understand biology but I'm aware that we all have our strengths and biology might not be one of them!

    Acromegaly is caused by prolonged overproduction of Growth Hormone (GH) by a pituitary gland tumour. The pituitary is a small gland at the base of the brain that produces several important hormones to control body functions such as growth and development, reproduction, and metabolism. An adenoma (tumour) in the pituitary gland at the base of the brain causes the excess production of growth hormone. These tumours are usually benign and grow slowly, gradually producing more and more GH. Most pituitary tumors arise spontaneously and are not genetically inherited. Many pituitary tumors arise from a genetic alteration in a single pituitary cell which leads to increased cell division and tumor formation. This genetic change permanently switches on the signal that tells the cells to divide and secrete growth hormone. In some instances, the tumor can be present in another organ of the cat's body, such as the pancreas or liver.

    Growth Hormone has several functions including the stimulation of production of insulin-like growth factor 1 (IGF-1) which is mainly made by the liver. Almost every cell in the human body is affected by IGF-1, especially cells in muscle, cartilage, bone, liver, kidney, nerves, skin, and lungs. IGF-1 also regulates cell growth and development, especially in nerve cells. IGF-1 attatches itself to a cell and says "Grow".

    As it's name suggests, IGF-1 is very similar in structure to insulin and in excess quantities (like in an acrocat) it competes with the cat's own insulin to fill the insulin receptor sites on the cell surfaces. However, IGF-1 doesn't do the same job as insulin (helping get the glucose into the cells) so an acrocat has high blood suagrs and needs huge amounts of insulin to out-compete the IGF-1 at the receptor sites. Think of the hormones (IGF-1 & insulin) as keys and the receptors on the cells as locks. You need the right key to put in the lock to open the door to the cell to get the job done. So with IGF-1 in an insulin receptor it's a bit like putting the wrong key into a lock - it doesn't open the door but it also prevents the right key from being used. In acrocats the pancreas still works just fine. It puts out insulin when there is glucose in the blood needing to be taken to the cells for fuel. The problem is that the pancreas can't kick out enough insulin to out compete the IGF-1 so we have to help by providing 'extra' insulin so there are more of the right kind of keys to make it into the locks.

    Once IGF-1 levels get to a certain level in the body, signals are sent back to the pituitary gland to reduce growth hormone out put. As the growth hormone levels drop so too does the IGF-1 levels. However, in an acrocat the tumour isn't listening. The pituitary tumour ignores the signal to turn things down & continues to make growth hormone. As a result the level of IGF-1 continues to rise to abnormally high levels.

    Prolonged high IGF-1 levels lead to the insulin resistance, organ and soft tissue growth (pot belly, narrowed airways) and changes in bone structures (big jaws, paws, longer limbs). It also means that even though the cat has uncontrolled diabetes and is not being able to effectively get all the nutrition it gets from it's food an acrocat often doesn't loose weight and might even gain weight.

    The Pituitary Gland naturally fluctuates the amount of hormones it gives out hour to hour, day to day, week to week. This is a normal process which sometimes can influence the tumour cells. This means that in some cats the tumour cells do not give out a constant flow of GH. The tumour cells are not so sensitive as the proper Pituitary Cells so the changes in the amount of unwanted GH are not necessarily obvious or predictable. However, it does mean that just how 'diabetic' an acrocat is on any given day can change. Several acrocats can go for several days (or weeks in some cases) with normal BGs because the amount of GH coming from the tumour has dropped, which drops the IGF-1 levels. Lower IGF-1 levels means the cat's own insulin 'keys' are sufficient to cope with the blood glucose levels (they're not being out numbered by too many IGF-1 keys in the insulin locks). That means the amount of insulin we need to give to help out is reduced.

    There is nothing we can do about the damaging effects of the excess IGF-1 (apart from considering raidiation therapy) so we try to decrease the damage done by high BGs for as long as possible. Also by limiting the damage of high BGs to the pancreas we are trying to make sure it's not damaged so that it can continue to help.

    There are three main tools (weapons?!) that we have to fight acromegaly in our cats:
    1. Appropriate diet
    2. Hometesting the BGs
    3. Appropriate Insulins & dosing schedules

    Beth & Pickles (GA)
    Norwich, UK
    Dx with Diabetes Mar 2005. Dx with Acromegaly Oct 2006
    Died: 11th July 2007 - Pancreatic cancer.

    Addendums from Patti and Merlin (2012)
    I'll add on here now that because of the increased tissue growth in the throat - we worry most about pilling acrocats. It's essential that one makes sure they receive food or something to drink afterwards. In some acrocats - as time progresses - it may become impossible to give them pills as they may not tolerate any whole pills at all.

    AND should an acrocat ever need to be anesthesized and have a breathing tube put in - they should have one size smaller placed than usual. Some acrocats have had difficulty with increased swelling AFTER the breathing tube is removed. Some vets aren't aware of this as they have not had experience with any of this.

    Due to the organ enlargement - some acrocats can develop cardiomyopathy and require medication. (Benazepril and Lasix)

    With the weight gain being due to the acromegaly - it is rarely if ever likely that you need to have an acrocat put on a "diet" to lose weight. It will be likely impossible.

    With the enlarged abdomen - this can cause pressure on their colon and cause constipation often requiring the kitties to need some sort of help with elimination. Many of us have found that Miralax helps with this.
  2. julie & punkin (ga)

    julie & punkin (ga) Well-Known Member

    Feb 17, 2011
    Edited 5/18/2015 to add information on how to get your cat tested for:
    Insulin Auto-Antibodies:

    thanks for posting that Patti - i hadn't seen the parts about pilling the cats or intubating them - good info to know.

    I gathered articles to send to my vet so Ithink i'll include them here. Some are on the acro/iaa/cushings forum, some are not, but since you've got this post going I'll add them on.

    Feline Aromegaly: An Underdiagnosed Endocrinopathy?
    J Vet Intern Med 2007;21:899–905

    Feline Diabetes Mellitus: How Relevant are Acromegaly, Hyperadrenocorticism and Pancreatitis as Underlying Disorders?
    Claudia E. Reusch,, DECVIM-CA
    Prof., Zurich, Switzerland
    35th World Small Animal Veterinary Association, Geneva, Switzerland June 2010

    Cryohypophysectomy used in the treatment of a case of feline acromegaly
    Journal of Small Animal Veterinary Medicine, June 2008
    S. L Blois, D. L Holmberg (full article in attachment below)
    (cryohypophysectomy: application of freezing temperatures to tumor)

    Outcomes of Pituitary Radiation in Cats

    Some Thoughts from Dr. Lunn, Colorado State University, on acro

    Feline Acromegaly
    Journal of Feline Medicine & Surgery, 2010

    Exogenous Insulin Treatment after Hypofractionated Radiotherapy in Cats with Diabetes Mellitus and Acromegaly
    Journal of Veterinary Internal Medicine
    M.D. Dunning1, C.S. Lowrie2, N.H. Bexfield1, J.M. Dobson1, M.E. Herrtage1
    Article first published online: 3 FEB 2009
    DOI: 10.1111/j.1939-1676.2008.0242.x
    Copyright © 2009 by the American College of Veterinary Internal Medicine (full article in attachment below)

    Attached Files:

    Last edited: May 31, 2016
    Reason for edit: 1.15.2015 to fix broken links 5/31/16 to add testing info in a more prominent location
  3. julie & punkin (ga)

    julie & punkin (ga) Well-Known Member

    Feb 17, 2011
    More recent articles:

    "Pituitary MRI Imaging in Cats with Acromegaly" September 10, 2012

    "Magnetic Resonance Imaging Findings in 15 Acromegalic Cats" March 29, 2011 have to pay to get full article
    acromegaly;cat;MRI;pituitary gland
    Feline acromegaly is characterized by chronic excessive growth hormone secretion, most commonly caused by a functional pituitary adenoma. In this study, acromegaly was diagnosed in 15 cats on the basis of compatible clinical signs, laboratory, and magnetic resonance imaging (MRI) findings. MRI findings were reviewed retrospectively. Enlargement of the pituitary gland with suprasellar extension was present in all cats. No characteristic signal patterns were identified on T1-weighted and T2-weighted sequences. Contrast enhancement was nonuniform in all cats, as was suspected involvement of the adjacent hypothalamus. A mass effect on the cavernous sinus and third ventricle was present in 13 cats. Mild peritumoral edema was present in four cats, and moderate edema in one cat. Transtentorial herniation was present in one cat. Histopathology confirmed the presence of a pituitary adenoma in two cases. MRI is a useful modality to establish the diagnosis of acromegaly.

    "Acromegaly Pathogenesis and Treatment" November 2009 (this is on humans, but the information is relevant to cats)
  4. Jill & Alex (GA)

    Jill & Alex (GA) Senior Member Moderator

    Dec 28, 2009
  5. Wendy&Neko

    Wendy&Neko Senior Member Moderator

    Feb 28, 2012
    Bumping and adding links to some recent articles I've found.

    "Feline Acromegaly" by Chelsea Sonius (Colorado State University) Spring 2011

    "Feline acromegaly: The keys to diagnosis" by Justin Wakayama DVM and David S. Bruyette DVM, DACVIM, October 1, 2013

    "Feline acromegaly: Treatment options" by ustin Wakayama DVM and David S. Bruyette DVM, DACVIM. October 1, 2013

    "Insulin Resistance in Cats" by J. Catharine Scott-Moncrieff, MS, MA, Vet MB, Veterinary Clinics of North America Small Animal Practice Vol 40, Issue 2 (2010)
    Last edited: Jan 24, 2016
    Reason for edit: fixed broken link
  6. Rebekah

    Rebekah Member

    Dec 18, 2013
    Thank you for this information, Wendy. I have been visiting the acro page for the past week or so. Ole has many acro symptoms without a doubt.
  7. julie & punkin (ga)

    julie & punkin (ga) Well-Known Member

    Feb 17, 2011
    Published 5/29/2015
    Studying Cat (Felis catus) Diabetes: Beware of the Acromegalic Imposter

    HS = hypersomatotropism = acromegaly
    DM = diabetes mellitus
    IGF-1 = Insulin-like Growth Factor-1; test that measures how much hormone is being produced. This hormone blocks the insulin receptors on cells, essentially preventing the cat's own insulin from being able to get into the cells and metabolize glucose appropriately.

    The current study suggests that HS caused by a pituitary adenoma or hyperplasia is common in the domestic cat with DM and explains the presence of DM in approximately 1 in 4 cats. Cats with HS often display an unremarkable phenotype, indistinguishable from cats with primary (type 2) DM. The current data therefore provide a warning for researchers and veterinarians working with the spontaneously diabetic cat to consider routinely screening such cats for the presence of HS-induced DM; serum IGF-1 was confirmed to be a relatively good tool for this. The encountered high prevalence and similarities between feline and human acromegaly emphasise great opportunities exist for valuable comparative acromegaly research benefiting all species suffering from this condition, including man."

    "most hypersomatotropism cats did not display typical phenotypical acromegaly signs."

    "Interestingly, all reported feline acromegalics have been diabetic, in contrast to the situation in man, where acromegaly induces DM only in a proportion of patients.

    "Over the 9-year-period 1221 diabetic cat samples were received by the laboratory for the purpose of fructosamine evaluation; these include the 184 cat samples initially evaluated in the pilot study [12]. Three hundred and nineteen samples (26.1%) demonstrated serum total IGF-1 concentrations higher than 1000 ng/ml (95% CI: 23.6–28.6%); the remaining samples with an IGF-1 < 1000 ng/ml had a mean+/-SD IGF-1 concentration of 468+/-221 ng/ml."...........(IGF-1 test results over 1000 in the UK labs indicate a positive diagnosis for acromegaly. Test results over 100 from Michigan State University are considered positive for acromegaly.)

    "It has been common practice to automatically suspect a cat with DM to be suffering from a form of diabetes akin to human type 2 DM. The current study suggests that this is an oversimplification. Approximately one in four of assessed diabetic cats were found to be suffering from HS-induced DM, which has a distinctly different aetiopathogenesis."

    "Interestingly, only a small proportion (24%) of clinicians submitting samples of cats which subsequently proved to be at high risk of having acromegaly (IGF-1 > 1000 ng/ml), reported they strongly suspected acromegaly to be present on the basis of the clinical picture. This is likely linked to the fact that acromegaly, like in humans [25], is a gradually progressive disease in cats. The occurrence of DM often precedes the soft tissue and bony changes classically associated with the disease in cats and diabetic signs are more acute in onset, as well as easier to spot for cat owners. This implies that an acromegalic diabetic cat can easily be mistaken for a non-acromegalic diabetic cat when only judging the phenotype. This is further demonstrated in the current study, with only 40% of confirmed acromegalic cats displaying abdominal organomegaly, 18% showing prognathia inferior, 13% “clubbed paws” and 37% broad facial features (of which only the latter proved statistically significantly increased in prevalence compared to a diabetic control group). The occurrence of respiratory stridor / snoring in cats with HS likely reflects reduced diameter of the nasopharynx, which occurs apparently as a result of thickening of soft tissues of the head [26]."

    "The potential of feline acromegaly providing novel angles to comparative acromegaly research was demonstrated in a recent study looking into the relationship between environmental toxin exposure and occurrence of endocrinopathies, using the acromegalic cat as a spontaneous model for the human disease. The study found that higher levels of organohalogenated chemicals, which can be found in any household and can induce pituitary oncogenesis, were present in the plasma of acromegalic household cats [4]."

    "Additionally, many acromegalic cats once effectively treated for the acromegaly, will go into diabetic remission, possibly suggesting their endocrine pancreas has not yet been subjected to overly long periods of the insulin resistance associated with acromegaly, leading to beta-cell exhaustion [16]. "
  8. suki & crystal (GA)

    suki & crystal (GA) Well-Known Member

    May 4, 2014
    Great work Julie and Wendy keeping us up to date on developments, lots of informative reading, thank you.
  9. julie & punkin (ga)

    julie & punkin (ga) Well-Known Member

    Feb 17, 2011
    Punkin  - acro changes.jpg [​IMG]The photos below show Punkin after and before his acromegaly diagnosis. I believe the left photo was taken in early 2012 and the right photo in 2009. He was diagnosed with diabetes in December 2010. Notice the changes in his forehead, lower jaw, and his feet in the "after" photo.
    Last edited by a moderator: Apr 16, 2020
    Reason for edit: fixed picture
  10. Wendy&Neko

    Wendy&Neko Senior Member Moderator

    Feb 28, 2012
    Some more general articles/presentations on acromegaly.

    Presentation by Dr. Kathy Lunn (NC State University) on Endocrine Updates: Pituitary Disease Diabetes Mellitus
    Includes a section on Glucose Toxicity and a section on Cushings too (Hyperadrenocorticism).

    Hypersomatotropism, Acromegaly, and Hyperadrenocorticism and FelineDiabetes Mellitus
    by Stijn J.M. Niessen, David B. Church, Yaiza Forcada, 2013
    (see attached)

    Acromegaly in Cats by Stijn J.M Niessen, Proceedings of WSAVA 2014

    Acromegaly in Cats: Are We Only Diagnosing the Tip of the Iceberg, Mark E. Peterson, Journal of Veterinary Internal Medicine, Volume 21, Issue 5, September 2007

    Articles on specific medical conditions with acrocats:

    Echocardiographic Findings in 11 Cats with Acromegaly, J.A. Myers, F.F. Lunn and J.M Bright, Journal of Veterinary Internal Medicine, Volume 28, Issue 4, July/August 2014

    Increased Serum Growth Hormone Concentration in Feline Hypertrophic Cardiopyopathy Mark D. Kieeltson, Paul D. Pion, Laura A. DeLellis, Yousry Mekhamer, Noel Dybdal, and Clinton D. Lothrop Jr. Journal of Veterinary Internal Medicine, Volume 6, Issue 6, publ November 1992

    Attached Files:

    Last edited: Oct 18, 2015
    Reason for edit: Attached file of Niessen article
    Marvin's Mom - Nat likes this.
  11. katieroc

    katieroc Member

    Oct 4, 2014
    Thanks so much to you all for posting this and the additional articles. The post is very easy to understand. Sometimes with medical articles, I follow up to a point and then I'm totally lost! I'm going to give this to my vet also. Also, thanks for the information about pilling and intubating. It's definitely valuable information to keep in mind.:cat:
  12. Wendy&Neko

    Wendy&Neko Senior Member Moderator

    Feb 28, 2012
    The number of articles on feline acromegaly is growing. Here are a few that talk about symptoms and what is happening inside our acrocats.

    Acromegaly in 14 Cats by Mark E Peterson, Deborah S. Greco, John F. Randolph, Scott D. Moroff, Clinton D. Lothrop
    Journal of Veterinary Internal Medicine, Volume 4, Issue 4, Feb. 2008
    Although this is an older article, it has a good description of what is happening inside the acromegalic cat, including symptoms and X-rays and CT scans. It also mentions the use of the shorter acting insulin R in managing the cat's diabetes.

    Abdominal Ultrasonographic Findings in Acromegalic Cats by Bianca N Lourenco, Elissa Randall, Gabriela Seiler, and Katharine F Lunn.
    Journal of Feline Medicine and Surgery, Vol. &, No 8, August 2015 (see attached)

    Computed Tomographic Signs of Acromegaly in 68 Diabetic Cats with Hypersomatotripism by Christopher R Lamb, Taízha C Ciasca, Panagiotis Mantis, Yaiza Forcada, Maegan Potter, David B Church and Stijn J Niessen
    Journal of Feline Medicine and Surgery, Vol 16(2), 2014

    Attached Files:

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