FREE SHIPPING over $40
OVER 10000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
The Canadian veterinary journal = La revue veterinaire canadienne2024; 65(4); 335-342; doi: 10.17226/11653

Spring and fall blood concentrations of adrenocorticotropic hormone, insulin, and thyroxine in healthy horses in Saskatchewan.

Abstract: To characterize concentrations of adrenocorticotropic hormone (ACTH), insulin, and thyroxine (T4) at 2 times of the year in healthy horses in Saskatchewan. Unassigned: A prospective, observational study was carried out in 52 healthy, client-owned horses. Inclusion criteria were no recent travel outside of Saskatchewan, normal physical examination findings, and no history or evidence of ongoing illness. Blood concentrations of ACTH, insulin and T4 were determined by chemiluminescence. Samples were collected in spring and fall and compared using the paired Student's -test or Wilcoxon signed-rank test. Generalized estimating equations were used to assess the associations between ACTH, T4, and insulin concentrations and gender, age, season, body condition score, glucose concentration, and breed. Unassigned: There were increases in both ACTH and insulin concentrations in the fall compared to spring ( < 0.001 and = 0.001, respectively). Other than season, insulin concentration was associated with breed, whereas ACTH concentration was associated with age. Finally, T4 concentration was associated with breed and glucose concentration, but not with season. Unassigned: These results highlighted the differences between spring and fall concentrations of both ACTH and insulin in healthy horses residing in the Canadian prairie provinces, which are known for extreme differences in summer and winter temperatures as well as day length. Geographically adjusted reference values are necessary to account for these variations, to improve diagnostic accuracy. This is the first published Canadian study evaluating these factors and their associations with hormone concentrations in clinically healthy animals. Concentrations sanguines printanières et automnales d’hormone adrénocorticotrope, d’insuline et de thyroxine chez des chevaux en bonne santé en Saskatchewan. Unassigned: Caractériser les concentrations d’hormone adrénocorticotrope (ACTH), d’insuline et de thyroxine (T4) à 2 moments de l’année chez des chevaux en bonne santé en Saskatchewan. Unassigned: Une étude observationnelle prospective a été réalisée auprès de 52 chevaux en bonne santé appartenant à des clients. Les critères d’inclusion étaient l’absence de voyage récent à l’extérieur de la Saskatchewan, les résultats normaux de l’examen physique et l’absence d’antécédents ou de signes de maladie persistante. Les concentrations sanguines d’ACTH, d’insuline et de T4 ont été déterminées par chimiluminescence. Des échantillons ont été collectés au printemps et à l’automne et comparés à l’aide du test de Student apparié ou du test du rang de signe de Wilcoxon. Des équations d’estimation généralisées ont été utilisées pour évaluer les associations entre les concentrations d’ACTH, de T4 et d’insuline et le sexe, l’âge, la saison, l’état corporel, la concentration de glucose et la race. Unassigned: Il y avait une augmentation des concentrations d’ACTH et d’insuline à l’automne par rapport au printemps ( < 0,001 et = 0,001, respectivement). Hormis la saison, la concentration d’insuline était associée à la race, alors que la concentration d’ACTH était associée à l’âge. Enfin, la concentration de T4 était associée à la race et à la concentration en glucose, mais pas à la saison. Unassigned: Ces résultats ont mis en évidence les différences entre les concentrations printanières et automnales d’ACTH et d’insuline chez les chevaux en bonne santé résidant dans les provinces des Prairies canadiennes, reconnues pour leurs différences extrêmes de températures estivales et hivernales ainsi que de durée du jour. Des valeurs de référence géographiquement ajustées sont nécessaires pour tenir compte de ces variations et améliorer la précision du diagnostic. Il s’agit de la première étude canadienne publiée évaluant ces facteurs et leurs associations avec les concentrations d’hormones chez des animaux cliniquement sains.(Traduit par D Serge Messier).
Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.
Get Full Text
Publication Date: 2024-04-02 PubMed ID: 38562984PubMed Central: PMC10945457DOI: 10.17226/11653Google 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.
LinkedInCopy
  • Observational Study
  • Veterinary
  • Journal Article

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 seeks to determine the differences in the levels of adrenocorticotropic hormone (ACTH), insulin, and thyroxine (T4) in healthy horses in Saskatchewan during spring and fall.

Methodology

  • The study was a prospective, observational type, involving 52 healthy, client-owned horses. Only horses which had not traveled recently outside Saskatchewan, had a normal physical examination findings, and no history or evidence of ongoing illness were included in the study.
  • The researchers used chemiluminescence to determine the blood concentrations of ACTH, insulin, and T4. The samples for the study were collected in spring and fall.
  • Data analysis was conducted using paired Student’s -test or Wilcoxon signed-rank test, to compare the spring and fall samples.
  • In addition, the researchers used Generalized Estimating Equations (GEE) to examine the relations between ACTH, T4, and insulin concentrations and variables such as gender, age, season, body condition score, glucose concentration, and breed.

Findings

  • It was found that there were increases in both ACTH and insulin concentrations in the fall compared to spring. Besides season, insulin concentration was found to be related to breed, while ACTH concentration was linked with age.
  • Moreover, T4 concentration was discovered to be associated with breed and glucose concentration, but not with the season.

Conclusion and Contributions

  • The study results emphasized the differences between spring and fall concentrations of both ACTH and insulin in healthy horses residing in the Canadian prairie provinces. As these provinces are known for their extreme differences in summer and winter temperatures as well as day length, the study highlights the need for geographically adjusted reference values. These adjustments would help to account for these variations, thereby improving diagnostic accuracy.
  • This study is notably the first published Canadian research evaluating these factors and their associations with hormone concentrations in clinically healthy animals.

Cite This Article

APA
Viviani P, Lavado RA, Chavarria NH, Ragno VM, Montgomery JB. (2024). Spring and fall blood concentrations of adrenocorticotropic hormone, insulin, and thyroxine in healthy horses in Saskatchewan. Can Vet J, 65(4), 335-342. https://doi.org/10.17226/11653

Publication

The Canadian veterinary journal = La revue veterinaire canadienne
ISSN: 0008-5286
NlmUniqueID: 0004653
Country: Canada
Language: English
Volume: 65
Issue: 4
Pages: 335-342

Researcher Affiliations

Viviani, Paula
  • Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4 (Viviani, Lavado, Chavarria, Ragno, Montgomery); University of São Paulo, 87 Av. Prof. Orlando Marques de Paiva, São Paulo 05508-900, Brazil (Lavado).
Lavado, Ronaldo Avella
  • Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4 (Viviani, Lavado, Chavarria, Ragno, Montgomery); University of São Paulo, 87 Av. Prof. Orlando Marques de Paiva, São Paulo 05508-900, Brazil (Lavado).
Chavarria, Nora H
  • Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4 (Viviani, Lavado, Chavarria, Ragno, Montgomery); University of São Paulo, 87 Av. Prof. Orlando Marques de Paiva, São Paulo 05508-900, Brazil (Lavado).
Ragno, Valentina M
  • Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4 (Viviani, Lavado, Chavarria, Ragno, Montgomery); University of São Paulo, 87 Av. Prof. Orlando Marques de Paiva, São Paulo 05508-900, Brazil (Lavado).
Montgomery, Julia B
  • Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4 (Viviani, Lavado, Chavarria, Ragno, Montgomery); University of São Paulo, 87 Av. Prof. Orlando Marques de Paiva, São Paulo 05508-900, Brazil (Lavado).

MeSH Terms

  • Humans
  • Horses
  • Animals
  • Adrenocorticotropic Hormone
  • Insulin
  • Thyroxine
  • Seasons
  • Saskatchewan
  • Prospective Studies
  • Glucose

References

This article includes 37 references
  1. Patterson-Kane JC, Karikoski NP, McGowan CM. Paradigm shifts in understanding equine laminitis. Vet J 2018;231:33–40.
    pubmed: 29429485
  2. McGowan TW, Pinchbeck GP, McGowan CM. Prevalence, risk factors and clinical signs predictive for equine pituitary pars intermedia dysfunction in aged horses. Equine Vet J 2013;45:74–79.
    pubmed: 22594955
  3. Ireland JL, McGowan CM. Epidemiology of pituitary pars intermedia dysfunction: A systematic literature review of clinical presentation, disease prevalence and risk factors. Vet J 2018;235:22–33.
    pubmed: 29704935
  4. Durham AE, Frank N, McGowan CM. ECEIM consensus statement on equine metabolic syndrome. J Vet Intern Med 2019;33:335–349.
    pmc: PMC6430910pubmed: 30724412
  5. Frank N, Tadros EM. Insulin dysregulation. Equine Vet J 2014;46:103–112.
    pubmed: 24033478
  6. Copas VEN, Durham AE. Circannual variation in plasma adrenocorticotropic hormone concentrations in the UK in normal horses and ponies, and those with pituitary pars intermedia dysfunction. Equine Vet J 2012;44:440–443.
    pubmed: 21848531
  7. McFarlane D, Paradis MR, Zimmel D. The effect of geographic location, breed, and pituitary dysfunction on seasonal adrenocorticotropin and α-melanocyte-stimulating hormone plasma concentrations in horses. J Vet Intern Med 2011;25:872–881.
    pubmed: 21745243
  8. 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;31:1533–1540.
    pmc: PMC5598888pubmed: 28661009
  9. Berglund L, Berne C, Svärdsudd K, Garmo H, Melhus H, Zethelius B. Seasonal variations of insulin sensitivity from a euglycemic insulin clamp in elderly men. Ups J Med Sci 2012;117:35–40.
    pmc: PMC3282240pubmed: 22066936
  10. Cepeda M, Muka T, Ikram MA, Franco OH, Schoufour JD. Seasonality of insulin resistance, glucose, and insulin among middle-aged and elderly population: The Rotterdam study. J Clin Endocrinol Metab 2018;103:946–955.
    pubmed: 29301043
  11. Beythien E, Wulf M, Ille N, Aurich J, Aurich C. Effects of sex, pregnancy and season on insulin secretion and carbohydrate metabolism in horses. Anim Reprod Sci 2017;184:86–93.
    pubmed: 28701287
  12. Williams CA, Kenny LB, Burk AO. Effects of grazing system, season, and forage carbohydrates on glucose and insulin dynamics of the grazing horse. J Anim Sci 2019;97:2541–2554.
    pmc: PMC6541809pubmed: 30911753
  13. Allen AL, Townsend HG, Doige CE, Fretz PB. A case-control study of the congenital hypothyroidism and dysmaturity syndrome of foals. Can Vet J 1996;37:349–351.
    pmc: PMC1576403pubmed: 8689594
  14. Fazio E, Medica P, Cravana C, Bruschetta G, Ferlazzo A. Seasonal thyroid and lipid profiles in thoroughbred pregnant and nonpregnant mares (Equus caballus). Theriogenology 2016;85:1582–1589.
    pubmed: 26920797
  15. Henneke DR, Potter GD, Kreider JL, Yeates BF. Relationship between condition score, physical measurements and body fat percentage in mares. Equine Vet J 1983;15:371–372.
    pubmed: 6641685
  16. National Research Council. Nutrient Requirements of Horses: Sixth Revised Edition. Washington, DC: The National Academies Press; 2007.
    doi: 10.17226/11653google scholar: lookup
  17. R Core Team. R: A language and environment for statistical computing. Vienna, Austria: R Foundation for Statistical Computing; 2021.
  18. Horn R, Bamford NJ, Afonso T. Factors associated with survival, laminitis and insulin dysregulation in horses diagnosed with equine pituitary pars intermedia dysfunction. Equine Vet J 2019;51:440–445.
    pubmed: 30417404
  19. Donaldson MT, McDonnell SM, Schanbacher BJ, Lamb SV, McFarlane D, Beech J. Variation in plasma adrenocorticotropic hormone concentration and dexamethasone suppression test results with season, age, and sex in healthy ponies and horses. J Vet Intern Med 2005;19:217–222.
    pubmed: 15822567
  20. Touitou Y, Haus E. Alterations with aging of the endocrine and neuroendocrine circadian system in humans. Chronobiol Int 2000;17:369–390.
    pubmed: 10841211
  21. Cordero M, Brorsen BW, McFarlane D. Circadian and circannual rhythms of cortisol, ACTH, and α-melanocyte-stimulating hormone in healthy horses. Domest Anim Endocrinol 2012;43:317–324.
    pubmed: 22717182
  22. Place NJ, McGowan CM, Lamb SV, Schanbacher BJ, McGowan T, Walsh DM. Seasonal variation in serum concentrations of selected metabolic hormones in horses. J Vet Intern Med 2010;24:650–654.
    pubmed: 20384949
  23. 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;30:653–663.
    pmc: PMC4913614pubmed: 26860336
  24. Beech J, Boston RC, McFarlane D, Lindborg S. Evaluation of plasma ACTH, α-melanocyte–stimulating hormone, and insulin concentrations during various photoperiods in clinically normal horses and ponies and those with pituitary pars intermedia dysfunction. J Am Vet Med Assoc 2009;235:715–722.
    pubmed: 19751169
  25. Macon EL, Harris P, Barker VD, Adams AA. Seasonal insulin responses to the oral sugar test in healthy and insulin dysregulated horses. J Equine Vet Sci 2022;113:103945.
    pubmed: 35405290
  26. Qiu LNY, Cai SV, Chan D, Hess RS. Seasonality and geography of diabetes mellitus in United States of America dogs. PLoS One 2022;17:e0272297.
    pmc: PMC9355170pubmed: 35930583
  27. Selim S, Elo K, Jaakkola S. Relationships among body condition, insulin resistance and subcutaneous adipose tissue gene expression during the grazing season in mares. PLoS One 2015;10:e0125968.
    pmc: PMC4418745pubmed: 25938677
  28. Rapson JL, Schott HC, Nielsen BD, McCutcheon LJ, Harris PA, Geor RJ. Effects of age and diet on glucose and insulin dynamics in the horse. Equine Vet J 2018;50:690–696.
    pubmed: 29356053
  29. Jacob SI, Geor RJ, Weber PSD, Harris PA, McCue ME. Effect of age and dietary carbohydrate profiles on glucose and insulin dynamics in horses. Equine Vet J 2018;50:249–254.
    pubmed: 28833406
  30. Breuhaus BA. Serum thyroid hormone and thyrotropin concentrations in adult horses as they age. J Equine Vet Sci 2018;68:21–25.
    pubmed: 31256883
  31. Walsh DM, McGowan CM, McGowan T, Lamb SV, Schanbacher BJ, Place NJ. Correlation of plasma insulin concentration with laminitis score in a field study of equine Cushing’s disease and equine metabolic syndrome. J Equine Vet Sci 2009;29:87–94.
  32. Singh BM, Goswami B, Mallika V. Association between insulin resistance and hypothyroidism in females attending a tertiary care hospital. Indian J Clin Biochem 2010;25:141–145.
    pmc: PMC3453097pubmed: 23105900
  33. Maratou E, Hadjidakis DJ, Kollias A. Studies of insulin resistance in patients with clinical and subclinical hypothyroidism. Eur J Endocrinol 2009;160:785–790.
    pubmed: 19141606
  34. Tuzcu A, Bacceci M, Gokalp D, Tuzun Y, Gunes K. Subclinical hypothyroidism may be associated with elevated high-sensitive c-reactive protein (low grade inflammation) and fasting hyperinsulinemia. Endocr J 2005;52:89–94.
    pubmed: 15758563
  35. Dimitriadis G, Mitrou P, Lambadiari V. Insulin action in adipose tissue and muscle in hypothyroidism. J Clin Endocrinol Metab 2006;91:4930–4937.
    pubmed: 17003097
  36. Horn R, Stewart AJ, Jackson KV, Dryburgh EL, Medina-Torres CE, Bertin F. Clinical implications of using adrenocorticotropic hormone diagnostic cutoffs or reference intervals to diagnose pituitary pars intermedia dysfunction in mature horses. J Vet Intern Med 2021;35:560–570.
    pmc: PMC7848300pubmed: 33368633
  37. Frank N, Elliott SB, Chameroy KA, Tóth F, Chumbler NS, McClamroch R. Association of season and pasture grazing with blood hormone and metabolite concentrations in horses with presumed pituitary pars intermedia dysfunction. J Vet Intern Med 2010;24:1167–1175.
    pubmed: 20666984

Citations

This article has been cited 1 times.
  1. 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.
    doi: 10.1111/jvim.70089pubmed: 40219807google scholar: lookup
Subscribe to our newsletter
Join 99,658 horse owners like you who receive our email updates on horse health and nutrition.