Comparison of the in-feed glucose test and the oral sugar test.
Abstract: The in-feed oral glucose test (OGT) and oral sugar test (OST) are advocated as field tests of insulin sensitivity in horses and ponies but have not been directly compared. Objective: To compare the insulin response to OGT and OST in 8 ponies and 5 horses of unknown insulin sensitivity. Methods: Experimental, randomised crossover study. Methods: Animals were fasted for 8 h overnight before and throughout testing. They were fed 1 g/kg bwt glucose powder with chaff (OGT) or 0.15 ml/kg bwt corn syrup (Karo™ Light Syrup; OST) was administered per os in a randomised crossover study with 48 h between tests. Blood samples were obtained at 0, 30, 60, 75, 90, 120 and 180 min. The maximal insulin concentration (Cmaxi ), time to maximal insulin concentration (Tmaxi ) and area under the curve of insulin concentration over time (AUCi ) for the tests were compared using Student's paired t test. The effect of individual subject, horse or pony and test were analysed using a linear mixed model. Results: The OGT Cmaxi (mean ± s.d.; 154 ± 116 μiu/ml), Tmaxi (136 ± 52 min) and AUCi (15,308 ± 9886 μiu/ml/min) were significantly (P<0.05) greater compared with the OST Cmaxi (72 ± 55 μiu/ml), Tmaxi (63 ± 25 min) and AUCi (5980 ± 4151 μiu/ml/min). The Cmaxi , Tmaxi and AUCi varied significantly between individual subjects. The Tmaxi was significantly different between horses and ponies during OGT and OST. Using previously defined criteria of insulin dysregulation, OGT identified 7/13 animals as insulin resistant, whereas OST identified 5/13 animals as insulin resistant. Conclusions: The OGT and OST showed agreement in identification of insulin dysregulation in 85% of equine subjects. Results of the OGT and OST are not comparable in all cases. Further work is required to establish which test more accurately diagnoses insulin dysregulation in horses and ponies.
© 2015 EVJ Ltd.
Publication Date: 2015-05-07 PubMed ID: 25582152DOI: 10.1111/evj.12413Google Scholar: Lookup
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- Journal Article
- Randomized Controlled Trial
- Research Support
- Non-U.S. Gov't
Summary
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The research focuses on comparing two insulin sensitivity tests, the in-feed oral glucose test (OGT) and the oral sugar test (OST), on horses and ponies. The OGT showed a higher response and variance among individual horses and ponies compared to the OST, but both tests were in agreement in identifying insulin dysregulation in 85% of the subjects.
Introduction
- The main aim of this study was to compare the results of the oral glucose test (OGT) and the oral sugar test (OST) performed on horses and ponies.
- Both of these methods are used as field tests for diagnosing insulin sensitivity in these animals, but there has been no direct comparison between them.
Methodology
- There were a total of 13 subjects (8 ponies and 5 horses) used in this randomised crossover study. Their insulin sensitivity levels were unknown prior to the study.
- Each subject was fasted overnight for 8 hours before the tests, and was not fed at all during the testing period.
- In the OGT, the subjects were given a diet of glucose powder mixed with chaff, while in the OST, corn syrup was provided.
- Blood samples were collected at various intervals following the ingestion of the glucose or corn syrup. The time-to-maximum insulin concentration (‘Tmaxi’), maximum insulin concentration (‘Cmaxi’), and area under the insulin concentration-time curve (‘AUCi’) were then compared.
Results
- The OGT had significantly greater values of Cmaxi, Tmaxi, and AUCi compared to the OST and the Tmaxi was significantly different among horses and ponies during both OGT and OST.
- It was also observed that there were significant variances in these insulin parameters between different individual subjects, showing that individual animals’ responses to these tests can vary greatly.
- There was an 85% agreement rate between the OGT and OST in terms of identifying insulin dysregulation in the subjects.
Conclusions
- The results of the two insulin sensitivity tests are not always comparable and require further research to establish which test more accurately diagnosis insulin dysregulation in horses and ponies.
- A significant finding was that 85% of the equine subjects showed agreement in insulin dysregulation when examined with both OGT and OST.
Cite This Article
APA
Smith S, Harris PA, Menzies-Gow NJ.
(2015).
Comparison of the in-feed glucose test and the oral sugar test.
Equine Vet J, 48(2), 224-227.
https://doi.org/10.1111/evj.12413 Publication
Researcher Affiliations
- The Royal Veterinary College, London, UK.
- WALTHAM Centre for Pet Nutrition, Waltham on the Wolds, Leicestershire, UK.
- The Royal Veterinary College, London, UK.
MeSH Terms
- Animals
- Area Under Curve
- Blood Glucose
- Cross-Over Studies
- Female
- Glucose / administration & dosage
- Glucose / pharmacology
- Glucose Tolerance Test
- Horses
- Insulin / metabolism
- Insulin Resistance
- Male
Citations
This article has been cited 17 times.- Delarocque J, Feige K, Carslake HB, Durham AE, Fey K, Warnken T. Development of a Web App to Convert Blood Insulin Concentrations among Various Immunoassays Used in Horses. Animals (Basel) 2023 Aug 24;13(17).
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- Warnken T, Schaub C, Delarocque J, Frers F, Feige K, Sonntag J, Reiche DB. Palatability, glycemic, and insulinemic responses to various carbohydrate formulations: Alternatives for the diagnosis of insulin dysregulation in horses?. J Vet Intern Med 2023 Jan;37(1):282-291.
- de Laat MA, Warnken T, Delarocque J, Reiche DB, Grob AJ, Feige K, Carslake HB, Durham AE, Sillence MN, Thane KE, Frank N, Brojer J, Lindase S, Sonntag J. Carbohydrate pellets to assess insulin dysregulation in horses. J Vet Intern Med 2023 Jan;37(1):302-314.
- Dunkel B, Knowles EJ, Chang YM, Menzies-Gow NJ. Influence of endocrine disease on l-lactate concentrations in blood of ponies. J Vet Intern Med 2021 May;35(3):1582-1588.
- Ericsson AC, Johnson PJ, Gieche LM, Zobrist C, Bucy K, Townsend KS, Martin LM, LaCarrubba AM. The Influence of Diet Change and Oral Metformin on Blood Glucose Regulation and the Fecal Microbiota of Healthy Horses. Animals (Basel) 2021 Apr 1;11(4).
- Leschke DH, Muir GS, Hodgson JK, Coyle M, Horn R, Bertin FR. Immunoreactive insulin stability in horses at risk of insulin dysregulation. J Vet Intern Med 2019 Nov;33(6):2746-2751.
- 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.
- Hodge E, Kowalski A, Torcivia C, Lindborg S, Stefanovski D, Hart K, Frank N, van Eps A. Effect of thyrotropin-releasing hormone stimulation testing on the oral sugar test in horses when performed as a combined protocol. J Vet Intern Med 2019 Sep;33(5):2272-2279.
- Moser K, Banse H. Comparison of the glucose and insulin responses of horses to 2 formulations of corn syrup. Can Vet J 2019 Jun;60(6):637-643.
- 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.
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- Frank N, Walsh DM. Repeatability of Oral Sugar Test Results, Glucagon-Like Peptide-1 Measurements, and Serum High-Molecular-Weight Adiponectin Concentrations in Horses. J Vet Intern Med 2017 Jul;31(4):1178-1187.
- Dunbar LK, Mielnicki KA, Dembek KA, Toribio RE, Burns TA. Evaluation of Four Diagnostic Tests for Insulin Dysregulation in Adult Light-Breed Horses. J Vet Intern Med 2016 May;30(3):885-91.
- Boshuizen B, De Maré L, Oosterlinck M, Van Immerseel F, Eeckhaut V, De Meeus C, Devisscher L, Vidal Moreno de Vega C, Willems M, De Oliveira JE, Hosotani G, Gansemans Y, Meese T, Van Nieuwerburgh F, Deforce D, Vanderperren K, Verdegaal EL, Delesalle C. Aleurone supplementation enhances the metabolic benefits of training in Standardbred mares: impacts on glucose-insulin dynamics and gut microbiome composition. Front Physiol 2025;16:1565005.
- Thane K, Sonntag J, Warnken T, Reiche D, Uricchio C, Frank N. Comparison of a customized glycemic pellets challenge with the oral sugar test to measure glycemic and insulinemic responses in horses. J Vet Intern Med 2024 Nov-Dec;38(6):3281-3287.
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