Felis ISSN 2398-2950

Acromegaly

Synonym(s): Growth hormone excess, hypersomatotropism

Contributor(s): Carmel Mooney, David Bruyette, Ellie Mardell

Introduction

  • Historically considered relatively rare endocrine disease.
  • Recognized with increasing frequency in recent years.
  • Chronic overgrowth of connective tissue, bone and viscera.
  • Cause: syndrome due to persistent excessive growth hormone (GH) secretion from pituitary adenoma Pituitary gland: neoplasia.
  • Signs:
  • Prognosis: survival time 8-30 months. Most die of complications, eg congestive heart failure Heart: congestive heart failure, renal failure Kidney: chronic kidney disease, neurological signs, or euthanazed due to painful polyarthropathy.
    Print off the owner factsheet on Acromegaly in cats Acromegaly in cats to give to your client.

Pathogenesis

Etiology

Pathophysiology

  • GH is synthesized in the pars distalis of pituitary gland.
  • Release is episodic and is controlled by growth hormone releasing hormone (GHrH) and inhibited by somatostatin.
  • The anabolic effect of GH ie soft tissue and skeletal growth and protein synthesis are mediated by insulin-growth factor (IGF-1).
  • The catabolic effects eg lipolysis and reduced cellular glucose transport are direct effects of GH.
  • Increased GH concentrations causes a reduction in the number of insulin receptors, reduced binding affinity and a post-receptor defect.
  • More insulin has to be produced to overcome these effects but hyperinsulinemia leads to further down regulation of receptors and ultimately DM.

Diagnosis

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Treatment

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Niessen S J (2010) Feline acromegaly, an essential differential diagnosis for the difficult diabetic. J Feline Med Surg 12 (1), 15-23 PubMed.
  • Dunning M D, Lowrie C S, Bexfield N H et al (2009) Exogenous insulin treatment after hypofractionated radiotherapy in cats with diabetes mellitus and acromegaly. JVIM 23 (2), 243-249 PubMed.
  • Berg R I, Nelson R W, Feldman E C et al (2007) Serum insulin-like growth factor-1 concentration in cats with diabetes mellitus and acromegaly. JVIM 21 (5), 892-898 PubMed.
  • Niessen S J, Petrie G, Gaudiano M et al (2007) Feline acromegaly: an underdiagnosed endocrinopathy? JVIM 21 (5), 889-905 PubMed.
  • Niessen S J, Khalid M, Petrie G et al (2007) Validation and application of a radioimmunoassay for ovine growth hormone in the diagnosis of acromegaly in cats. Vet Rec 160 (26), 902-907 PubMed.
  • Brearley M J, Polton G A, Littler R M et al (2006) Coarse fractionated radiation therapy for pituitary tumours in cats: a retrospective study of 12 cases. Vet Comp Oncol 4 (4), 209-217 PubMed.
  • Mayer M N, Greco D S, LaRue S M (2006) Outcomes of pituitary irradiation in cats. JVIM 20 (5), 1151-1154 PubMed.
  • Starkey S R, Tan K, Church D B (2004) Investigation of IGF-1 levels amongst diabetes and non-diabetic cats. J Feline Med Surg (3), 149-155 PubMed.
  • Elliot D A, Feldman E C, Koblik P D et al (2000) Prevalence of pituitary tumors among diabetic cats with insulin resistance. JAVMA 216 (11), 1765-1768 PubMed.
  • Feldman E C & Nelson R W (2000) Acromegaly and hyperadrenocorticism in cats - a clinical perspective. J Feline Med Surg (3), 153-158 PubMed.
  • Norman E J & Mooney C T (2000) Diagnosis and management of diabetes mellitus in five cats with somatotrophic abnormalities. J Feline Med Surg (4), 183-190 PubMed.
  • Goossens M M, Feldman E C, Nelson R W et al (1998) Cobalt 60 irradiation of pituitary gland tumors in three cats with acromegaly. JAVMA 213 (3), 374-376 PubMed.
  • Merchant S R, Taboada J (1995) Systemic diseases with cutaneous manifestations. Vet Clin North Am Small Anim Pract 25 (4), 945-959 PubMed.
  • Peterson M E, Taylor R S, Greco D S et al (1990) Acromegaly in 14 cats. JVIM (4), 192-201 PubMed.
  • Morrison S A, Randolph J, & Lothrop C D Jr. (1989) Hypersomatotropism and insulin resistant diabetes mellitus in a cat. JAVMA 194 (1), 91-94 PubMed.
  • Wolf A M (1989) Feline endocrinology. Tijdschr Diergeneeskd 114 (Suppl 1), 15S-18S PubMed.


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