Seasonal variation in serum concentrations of selected metabolic hormones in horses.
Abstract: Determination of adrenocorticotropic hormone (ACTH) concentration is a commonly used test in the evaluation of endocrine causes of equine laminitis, but the concentration in healthy horses can be high at certain times of year, which alters the specificity of the ACTH test. Objective: To determine if circulating concentrations of ACTH, cortisol, glucose, insulin, and thyroxine vary month to month in healthy horses and in horses with equine metabolic syndrome (EMS). Methods: Nine healthy adult horses were studied on their farm/stable over the course of 1 year. After the diagnosis of EMS, 10 laminitic horses residing at the same farm/stable were also studied. Methods: Prospective study of healthy and laminitic horses. Plasma/serum samples were analyzed for concentrations of hormones and glucose. Results: ACTH was the only analyte to show a discrete seasonal pattern, with concentrations in healthy and EMS horses frequently outside of the reference range (9-35 pg/mL) in August through October. Insulin was elevated (>40 microIU/mL) in EMS horses during most months and median serum glucose was generally higher in EMS horses (100 mg/dL, range, 76-163 mg/ dL) than in controls (94 mg/dL, range, 56-110 mg/dL), but no seasonal patterns for insulin or glucose were found. Conclusions: An increased ACTH concentration in horses in late summer or autumn should be interpreted with caution. In contrast, insulin concentration is maintained within the reference range throughout the year in healthy horses, thus an increased insulin concentration at any time of year should raise suspicions of EMS, ECD, or both.
Publication Date: 2010-04-02 PubMed ID: 20384949DOI: 10.1111/j.1939-1676.2010.0500.xGoogle Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research article explores the seasonal variations in metabolic hormones in healthy horses as well as those suffering from equine metabolic syndrome (EMS), in an attempt to better understand the use of adrenocorticotropic hormone (ACTH) testing in diagnosing equine laminitis.
Objective of Study
- The paper’s main goal is to ascertain whether the levels of ACTH, cortisol, glucose, insulin, and thyroxine – critical hormones in the metabolic system of horses – vary month to month in healthy horses as well as those with EMS.
Methodology
- The study was conducted on nine healthy adult horses and, following the diagnosis of EMS, ten laminitic horses at the same farm/stable over a year.
- Plasma and serum samples were collected and examined to determine the concentrations of various metabolic-related hormones and glucose.
Results
- ACTH emerged as the only hormone which showed a distinct seasonal pattern, having levels frequently out of the normal range in both healthy and EMS horses during August through October.
- Although insulin was found to be elevated in EMS horses throughout most months, it did not display any evident seasonal variations. No seasonal patterns for glucose were detected too.
- Median serum glucose was typically higher in EMS horses compared to the control group, indicating a possible correlation between elevated glucose levels and EMS.
Conclusions
- The increased ACTH concentration in horses during the late summer or autumn months must be interpreted carefully.
- Contrarily, stable insulin concentration within the reference range all year-round in healthy horses, points toward any significant rise in insulin being indicative of potential health disorders, such as EMS or ECD.
In conclusion, this research delivers critical insights on hormonal fluctuations in horses, potentially aiding in improved diagnostic accuracy for equine metabolic syndrome and laminitis.
Cite This Article
APA
Place NJ, McGowan CM, Lamb SV, Schanbacher BJ, McGowan T, Walsh DM.
(2010).
Seasonal variation in serum concentrations of selected metabolic hormones in horses.
J Vet Intern Med, 24(3), 650-654.
https://doi.org/10.1111/j.1939-1676.2010.0500.x Publication
Researcher Affiliations
- Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY 14851, USA. njp27@cornell.edu
MeSH Terms
- Adrenocorticotropic Hormone / blood
- Animals
- Blood Glucose
- Foot Diseases / blood
- Foot Diseases / metabolism
- Hoof and Claw / pathology
- Horse Diseases / blood
- Horse Diseases / metabolism
- Horses
- Hydrocortisone / blood
- Insulin / blood
- Metabolic Syndrome / blood
- Metabolic Syndrome / veterinary
- Seasons
- Thyroxine / blood
- Time
Citations
This article has been cited 16 times.- Moss A, Leise B, Hackett E. Stress response as a contributing factor in horses with laminitis. J Vet Sci 2023 Mar;24(2):e33.
- Weinert-Nelson JR, Biddle AS, Sampath H, Williams CA. Fecal Microbiota, Forage Nutrients, and Metabolic Responses of Horses Grazing Warm- and Cool-Season Grass Pastures. Animals (Basel) 2023 Feb 22;13(5).
- Kirkwood NC, Hughes KJ, Stewart AJ. Pituitary Pars Intermedia Dysfunction (PPID) in Horses. Vet Sci 2022 Oct 10;9(10).
- Alberghina D, Statelli A, Monteverde V, Vazzana I, Cascone G, Panzera M. Serum Cortisol and Its Correlation with Leucocyte Profile and Circulating Lipids in Donkeys (Equus asinus). Animals (Basel) 2022 Mar 26;12(7).
- Ničová K, Bartošová J. Still beyond a chance: Distribution of faults in elite show-jumping horses. PLoS One 2022;17(3):e0264615.
- Karikoski NP, Box JR, Mykkänen AK, Kotiranta VV, Raekallio MR. Variation in insulin response to oral sugar test in a cohort of horses throughout the year and evaluation of risk factors for insulin dysregulation. Equine Vet J 2022 Sep;54(5):905-913.
- Tsuchiya T, Noda R, Ikeda H, Maeda M, Sato F. Relationship between endogenous plasma adrenocorticotropic hormone concentration and reproductive performance in Thoroughbred broodmares. J Vet Intern Med 2021 Jul;35(4):2002-2008.
- Hu K, Stewart AJ, Yuen KY, Hinrichsen S, Dryburgh EL, Bertin FR. The effect of freeze-thaw cycles on determination of immunoreactive plasma adrenocorticotrophic hormone concentrations in horses. J Vet Intern Med 2020 May;34(3):1350-1356.
- 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.
- Shawaf T, Hussen J, Al-Zoubi M, Hamaash H, Al-Busadah K. Impact of season, age and gender on some clinical, haematological and serum parameters in Shetland ponies in east province, Saudi Arabia. Int J Vet Sci Med 2018 Jun;6(1):61-64.
- Secombe CJ, Tan RHH, Perara DI, Byrne DP, Watts SP, Wearn JG. The Effect of Geographic Location on Circannual Adrenocorticotropic Hormone Plasma Concentrations in Horses in Australia. J Vet Intern Med 2017 Sep;31(5):1533-1540.
- Bertin FR, Taylor SD, Bianco AW, Sojka-Kritchevsky JE. The Effect of Fasting Duration on Baseline Blood Glucose Concentration, Blood Insulin Concentration, Glucose/Insulin Ratio, Oral Sugar Test, and Insulin Response Test Results in Horses. J Vet Intern Med 2016 Sep;30(5):1726-1731.
- Hart KA, Wochele DM, Norton NA, McFarlane D, Wooldridge AA, Frank N. Effect of Age, Season, Body Condition, and Endocrine Status on Serum Free Cortisol Fraction and Insulin Concentration in Horses. J Vet Intern Med 2016 Mar-Apr;30(2):653-63.
- Hart KA, Barton MH. Adrenocortical insufficiency in horses and foals. Vet Clin North Am Equine Pract 2011 Apr;27(1):19-34.
- Lopes A, Huber L, Durham AE. The Seasonality of Serum Insulin Concentrations in Equids and the Association With Breed, Age, and Sex. J Vet Intern Med 2025 May-Jun;39(3):e70089.
- Viviani P, Lavado RA, Chavarria NH, Ragno VM, Montgomery JB. Spring and fall blood concentrations of adrenocorticotropic hormone, insulin, and thyroxine in healthy horses in Saskatchewan. Can Vet J 2024 Apr;65(4):335-342.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
