Repeatability of the combined glucose-insulin tolerance test and the effect of a stressor before testing in horses of 2 breeds.
Abstract: The increasing number of horses diagnosed with insulin resistance (IR) and the suggested link between IR and laminitis has highlighted the need to accurately diagnose IR in clinical practice. Objective: The aim of the study was to evaluate the repeatability of the combined glucose-insulin tolerance test (CGIT) as well as to determine the effect of 2 different breeds and the effect of a stressor on the test results. Methods: Clinically normal horses, 9 Standardbred horses and 9 Icelandic horses. Methods: Prospective clinical nonrandomized trial. The CGIT was performed on all horses on 2 occasions 3 weeks apart. An additional CGIT was performed on four of the Standardbred and four of the Icelandic horses after transportation to a new environment (stressor) the day before testing. Results: Calculated parameters for the glucose curve of the CGIT had low repeatability, whereas the parameters for the insulin curve had high repeatability. There was an effect of breed (Standarbred versus Icelandic horse) as well as stress on the glucose dynamics, but not on the insulin dynamics of the CGIT. Conclusions: Repeatability of the glucose dynamics of the CGIT is low. In addition, there appears to be breed differences in the glucose dynamics. It is therefore suggested that diagnosis of IR should not be made solely based on results from the glucose curve of the CGIT.
Copyright © 2013 by the American College of Veterinary Internal Medicine.
Publication Date: 2013-08-28 PubMed ID: 24033635DOI: 10.1111/jvim.12172Google Scholar: Lookup
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- Clinical Trial
- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research focused on the repeatability and reliability of the Combined Glucose-Insulin Tolerance Test (CGIT) in diagnosing insulin resistance (IR) in horses, taking into consideration the influence of stress and breed differences.
Research Objectives
- The researchers aimed to evaluate the efficacy and repeatability of the Combined Glucose-Insulin Tolerance Test (CGIT) for accurately diagnosing insulin resistance (IR) in horses.
- They further aimed to determine the influence of specific factors – breed differences and exposure to stressors – on the results of the CGIT.
Methods
- The study was carried out on 18 clinically normal horses – 9 Standardbred and 9 Icelandic.
- A prospective clinical nonrandomized trial was performed. They applied the CGIT on all the horses twice, with a three-week interval.
- Subsequently, an additional CGIT was carried out on four horses from each breed after they were subjected to the stressor of transportation to a new environment a day before the test.
Results
- The findings revealed that the parameters used for calculating the glucose curve of the CGIT had low repeatability, while the insulin curve parameters showed high repeatability.
- The results further demonstrated a significant effect of the breed (Standardbred versus Icelandic) and stress on the glucose dynamics. However, these factors did not affect the insulin dynamics of the CGIT.
Conclusion
- The researchers concluded that the repeatability of the glucose dynamics of the CGIT test is low, indicating it may not be a reliable indicator alone.
- Moreover, there appeared to be breed differences in the glucose dynamics which the researchers suggest should be taken into account.
- Therefore, the researchers caution that the diagnosis of insulin resistance should not be made solely based on the results from the glucose curve of the CGIT.
Cite This Article
APA
Bröjer J, Lindåse S, Hedenskog J, Alvarsson K, Nostell K.
(2013).
Repeatability of the combined glucose-insulin tolerance test and the effect of a stressor before testing in horses of 2 breeds.
J Vet Intern Med, 27(6), 1543-1550.
https://doi.org/10.1111/jvim.12172 Publication
Researcher Affiliations
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden.
MeSH Terms
- Animals
- Area Under Curve
- Blood Glucose / analysis
- Female
- Glucose Tolerance Test / standards
- Glucose Tolerance Test / veterinary
- Horses / metabolism
- Insulin / blood
- Insulin Resistance / physiology
- Male
- Prospective Studies
- Reproducibility of Results
Citations
This article has been cited 12 times.- Timko KJ, Hostnik LD, Watts MR, Chen C, Bercz A, Toribio RE, Belknap JK, Burns TA. Diagnostic evaluation of insulin and glucose dynamics in light-breed horses receiving dexamethasone. Can Vet J 2022 Jun;63(6):617-626.
- Montoya B, Briga M, Jimeno B, Verhulst S. Glucose regulation is a repeatable trait affected by successive handling in zebra finches. J Comp Physiol B 2020 Jul;190(4):455-464.
- Horn R, Bertin FR. Evaluation of combined testing to simultaneously diagnose pituitary pars intermedia dysfunction and insulin dysregulation in horses. J Vet Intern Med 2019 Sep;33(5):2249-2256.
- Durham AE, Frank N, McGowan CM, Menzies-Gow NJ, Roelfsema E, Vervuert I, Feige K, Fey K. ECEIM consensus statement on equine metabolic syndrome. J Vet Intern Med 2019 Mar;33(2):335-349.
- Lindåse S, Nostell K, Bröjer J. A modified oral sugar test for evaluation of insulin and glucose dynamics in horses. Acta Vet Scand 2016 Oct 20;58(Suppl 1):64.
- de Laat MA, Hampson BA, Sillence MN, Pollitt CC. Sustained, Low-Intensity Exercise Achieved by a Dynamic Feeding System Decreases Body Fat in Ponies. J Vet Intern Med 2016 Sep;30(5):1732-1738.
- Warnken T, Huber K, Feige K. Comparison of three different methods for the quantification of equine insulin. BMC Vet Res 2016 Sep 9;12(1):196.
- Morgan R, Keen J, McGowan C. Equine metabolic syndrome. Vet Rec 2015 Aug 15;177(7):173-9.
- Thane K, Voth R, Klee R, Warnken T, Chukwu V, Frank N. Effects of the Sodium-Glucose Cotransporter-2 Inhibitor Velagliflozin on Insulin Concentrations in Horses With Insulin Dysregulation. J Vet Intern Med 2025 Nov-Dec;39(6):e70256.
- Galinelli NC, Bamford NJ, Erdody ML, Mackenzie SA, Warnken T, Harris PA, Sillence MN, Bailey SR. Effect of pergolide treatment on insulin dysregulation in horses and ponies with pituitary pars intermedia dysfunction. Equine Vet J 2025 Nov;57(6):1612-1622.
- Sigurðardóttir H, Ablondi M, Kristjansson T, Lindgren G, Eriksson S. Genetic diversity and signatures of selection in Icelandic horses and Exmoor ponies. BMC Genomics 2024 Aug 8;25(1):772.
- Söder J, Bröjer JT, Nostell KE. Interday variation and effect of transportation on indirect blood pressure measurements, plasma endothelin-1 and serum cortisol in Standardbred and Icelandic horses. Acta Vet Scand 2012 Jun 10;54(1):37.
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