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Equine veterinary journal2023; 56(2); 361-367; doi: 10.1111/evj.14019

Insulin, but not adiponectin, is detectable in equine saliva using an automated, commercial assay.

Abstract: The hormones insulin and adiponectin are commonly measured in equids because of their involvement in endocrinopathic laminitis. These are currently measured in serum/plasma, although jugular venipuncture can cause stress in some animals and may be impossible in needle-shy individuals. However, both hormones can be measured in saliva in other species. Objective: To determine whether [insulin] and [total adiponectin] are detectable in equine saliva using automated assays and whether saliva collection is associated with changes in stress indicators. Additionally, the correlation between serum and salivary [insulin] was investigated. Methods: In vivo experiment. Methods: Paired blood and saliva samples were collected from eight adult ponies at multiple time-points (n = 45 paired samples). [Insulin] and [total adiponectin] were measured using automated assays validated for equine serum/plasma. Blink rates and heart rates were determined, using video recordings and a wearable heart rate monitor respectively, to assess the effects of sample collection on stress indicators compared with a control situation without a stressful stimulus. Results: [Total adiponectin] was undetectable in saliva. However, salivary [insulin] was measurable with acceptable inter-assay (1.3 ± 0.9%) and intra-assay (1.1 ± 0.6%) variability. Blink and heart rates during saliva collection did not differ significantly from those in the control setting. Serum and salivary [insulin] were not significantly correlated. Conclusions: Small sample size comprising native UK ponies; potential sampling bias as animals were recruited to the study partly based on their behaviour during blood sampling; saliva collected from unfasted animals. Conclusions: Insulin is measurable in equine saliva using an automated assay currently available in the UK, but further validation and the determination of specific diagnostic thresholds are required. Saliva collection was not associated with changes in stress indicators. Further research is therefore needed to determine the potential of equine saliva as a non-invasive alternative to blood for insulin determination.
© 2023 MARS Horsecare and The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.
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Publication Date: 2023-10-23 PubMed ID: 37872702DOI: 10.1111/evj.14019Google Scholar: Lookup
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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 study investigated the feasibility of detecting insulin and adiponectin, hormones important for horse health, in equine saliva instead of blood. The research found insulin but not adiponectin is measurable in horse saliva using automated methods.

Objective

  • The primary goal of this research was to determine if insulin and adiponectin – hormones that are typically measured in horses due to the significant role they play in endocrinopathic laminitis – could be detected in equine saliva using automated assays.

Methods

  • The study involved an in vivo experiment with eight adult ponies from which blood and salivary samples were taken at various times.
  • The hormones insulin and adiponectin were measured with automated assays that had been previously validated for equine serum and plasma.
  • To consider potential stress caused by sample collection, blink rates and heart rates were assessed using video recordings and a wearable heart rate monitor and compared with a control situation without a stress stimulus.

Results

  • Adiponectin was not found in the sampled horse saliva.
  • Insulin, however, was measurable in equine saliva with satisfactory inter-assay and intra-assay variability.
  • No significant changes were observed in the animals’ blink and heart rates during saliva collection in comparison to the control situation, indicating that the collection of saliva did not induce notable stress in the equines.
  • The correlation between insulin levels in serum and saliva was not significant.

Conclusions and Future Directions

  • This study was carried out on a small sample size of native UK ponies. There could have been potential sampling bias as the equines were chosen for the study partially based on their behavior during blood sampling, and the saliva samples were taken from animals that were not fasting.
  • The research concluded that insulin is measurable in horse saliva using an automated assay, yet it needs further validation and specific diagnostic thresholds need to be set.
  • The researchers also state the need for more research to confirm the potential of horse saliva as a non-invasive alternative to be used for insulin determination.

Cite This Article

APA
Barnabé MA, Elliott J, Harris PA, Menzies-Gow NJ. (2023). Insulin, but not adiponectin, is detectable in equine saliva using an automated, commercial assay. Equine Vet J, 56(2), 361-367. https://doi.org/10.1111/evj.14019

Publication

Equine veterinary journal
ISSN: 2042-3306
NlmUniqueID: 0173320
Country: United States
Language: English
Volume: 56
Issue: 2
Pages: 361-367

Researcher Affiliations

Barnabé, Marine A
  • Department of Clinical Sciences and Services, Royal Veterinary College, Hertfordshire, UK.
Elliott, Jonathan
  • Department of Comparative Biomedical Sciences, Royal Veterinary College, Hertfordshire, UK.
Harris, Patricia A
  • Equine Studies Group, Waltham Petcare Science Institute, Leicestershire, UK.
Menzies-Gow, Nicola J
  • Department of Clinical Sciences and Services, Royal Veterinary College, Hertfordshire, UK.

MeSH Terms

  • Humans
  • Horses
  • Animals
  • Insulin
  • Adiponectin
  • Saliva
  • Endocrine System Diseases / veterinary
  • Horse Diseases

Grant Funding

  • Royal Veterinary College
  • Waltham Centre for Pet Nutrition

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Citations

This article has been cited 2 times.
  1. Ji F, Lee HS, Kim JH. Resistance exercise and skeletal muscle: protein synthesis, degradation, and controversies. Eur J Appl Physiol 2025 Sep;125(9):2353-2382.
    doi: 10.1007/s00421-025-05832-zpubmed: 40512179google scholar: lookup
  2. Hansen S, Otten ND, Ceron JJ, González-Arostegui LG, Peres-Rubio C. Redox Biomarker Variations With Severity of Asthma in Horses Across Different Sample Types. J Vet Intern Med 2025 Mar-Apr;39(2):e70031.
    doi: 10.1111/jvim.70031pubmed: 40035177google scholar: lookup
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