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Equine veterinary journal2004; 36(3); 295-298; doi: 10.2746/0425164044877288

Serum insulin concentrations in horses with equine Cushing’s syndrome: response to a cortisol inhibitor and prognostic value.

Abstract: Serum insulin concentration and its use as a prognostic indicator in horses with equine Cushing's syndrome (ECS) have been poorly documented. Objective: To examine daily insulin variations in horses with ECS and the effect of treatment using trilostane, a competitive inhibitor of 3beta-hydroxysteroid dehydrogenase. Further, we aimed to examine the relationship between baseline serum insulin concentration and survival in horses with ECS. Methods: Basal serum insulin concentrations were measured in 20 confirmed ECS cases by taking blood at regular 4 h intervals for 24 h (1200, 1600, 2000, 2400, 0400 and 0800 h) before treatment (Day 0) and 10 days, and 30 days and 1-2 years after the onset of trilostane therapy. The temporal pattern of insulin was analysed using a linear mixed model approach, and the prognostic value of measurements on Day 0 assessed using receiver-operating characteristic analysis. Results: Horses with ECS showed a diurnal pattern of serum insulin concentration, highest value at 1200 h, and this pattern was not altered by treatment with trilostane. Furthermore, despite a mild increase of serum insulin concentrations after 10 days of trilostane therapy, insulin concentration was unaffected in the long-term. Low serum insulin concentrations at the beginning of the trial were significantly associated with improved survival to 1-2 years. The 1200 h sampling before treatment had the highest prognostic value for prediction of survival with a sensitivity and specificity of at least 90% for serum insulin at 188 microu/ml to predict survival and nonsurvival, respectively. Conclusions: Insulin is a useful prognostic indicator for ECS, but potentially large variations can occur throughout a 24 h period, indicating a single sample may not be representative. Serum insulin concentration did not increase over 1-2 years in horses receiving trilostane therapy.
Publication Date: 2004-05-19 PubMed ID: 15147141DOI: 10.2746/0425164044877288Google Scholar: Lookup
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  • Journal Article

Summary

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The research article discusses the relation between serum insulin concentrations in horses diagnosed with equine Cushing’s syndrome (ECS) and the impact of treatment using trilostane, a cortisol inhibitor. The study also evaluates the prognostic value of serum insulin levels, signifying the potential to predict the survival rates of the animals afflicted with ECS.

Objective and Methodology

  • The study aimed to investigate daily variations in insulin levels in horses affected by ECS and the possible effects of trilostane treatment on these levels.
  • The researchers also aimed to scrutinize the correlation between baseline serum insulin concentration and survival rates in horses suffering from ECS.
  • The study involved 20 diagnosed ECS cases and blood samples were taken every 4 hours over a 24 hour period before treatment, as well as at various intervals post treatment commencement.
  • A linear mixed-model approach was used for analyzing the temporal pattern of insulin, and the prognostic value of measurements on Day 0 were examined using receiver-operating characteristic analysis.

Findings

  • The study revealed that horses with ECS demonstrated a diurnal pattern of serum insulin concentration, with the highest value noted at 1200 h. This pattern remained unchanged despite trilostane treatment.
  • The serum insulin concentration showed a mild increase after 10 days of trilostane therapy but remained stable over the long-term.
  • Lower serum insulin concentrations at the onset of the trial were significantly linked to improved survival rates over a 1-2 year period.
  • Interestingly, the 1200 h sampling before treatment demonstrated the highest prognostic value for predicting survival, with a sensitivity and specificity of at least 90% for serum insulin levels at 188 microu/ml to predict survival and non-survival, respectively.

Conclusions

  • The examination concluded that insulin proves to be a functional prognostic indicator for ECS, although potential large variations can occur during a 24 h period, indicating that a single sample may not always be representative.
  • Additionally, it was established that the serum insulin concentration did not significantly rise over a 1-2 year period in horses undergoing trilostane therapy.

Cite This Article

APA
McGowan CM, Frost R, Pfeiffer DU, Neiger R. (2004). Serum insulin concentrations in horses with equine Cushing’s syndrome: response to a cortisol inhibitor and prognostic value. Equine Vet J, 36(3), 295-298. https://doi.org/10.2746/0425164044877288

Publication

ISSN: 0425-1644
NlmUniqueID: 0173320
Country: United States
Language: English
Volume: 36
Issue: 3
Pages: 295-298

Researcher Affiliations

McGowan, C M
  • Department of Veterinary Clinical Sciences, The Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire AL9 7TA, UK.
Frost, R
    Pfeiffer, D U
      Neiger, R

        MeSH Terms

        • 3-Hydroxysteroid Dehydrogenases / metabolism
        • Animals
        • Biomarkers / blood
        • Cushing Syndrome / blood
        • Cushing Syndrome / drug therapy
        • Cushing Syndrome / veterinary
        • Dihydrotestosterone / analogs & derivatives
        • Dihydrotestosterone / therapeutic use
        • Enzyme Inhibitors / therapeutic use
        • Horse Diseases / blood
        • Horse Diseases / drug therapy
        • Horses
        • Hydrocortisone / antagonists & inhibitors
        • Hydrocortisone / blood
        • Insulin / blood
        • Predictive Value of Tests
        • Prognosis
        • Sensitivity and Specificity
        • Survival Analysis

        Citations

        This article has been cited 17 times.
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