Effects of equine metabolic syndrome on inflammation and acute-phase markers in horses

• Published in: Domestic animal endocrinology Vol. 72; p. 106448
• Main Authors: Zak, A., Siwinska, N., Elzinga, S., Barker, V.D., Stefaniak, T., Schanbacher, B.J., Place, N.J., Niedzwiedz, A., Adams, A.A.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.07.2020
• Subjects: Activin A; Acute-phase proteins; IL-6; Insulin dysregulation; Obesity; Obesity; Activin A; Acute-phase proteins; IL-6; Insulin dysregulation
• ISSN: 0739-7240; 1879-0054
• DOI: 10.1016/j.domaniend.2020.106448

Obesity and metabolic disorders are associated with systemic low-grade chronic inflammation, both in humans and animals. The aim of the study is to assess the effects of obesity and hyperinsulinemia on individual components of the acute-phase reaction in equine metabolic syndrome (EMS) horses. Eight mixed-breed EMS and six control, age-matched horses of both sexes were included in the study. Animals were classified as EMS or control based on the assessment of BCS, cresty neck score, and basal insulin >50 μU/mL and/or insulin responses to the oral sugar test (OST) >60 μU/mL. Peripheral venous blood was collected. The expression of proinflammatory cytokines, the concentration of circulating cytokines, and acute-phase proteins (serum amyloid A, C-reactive protein, haptoglobin, activin A, and procalcitonin) were measured. The data were analyzed using the Mann-Whitney test, whereas correlations were examined using Spearman's correlation coefficient. The tests were statistically significant if P ≤ 0.05. There were no differences in cytokine gene expression, circulating cytokine concentrations, or concentrations of acute-phase proteins between the EMS and the control groups. There was a strong correlation between the basal concentration of insulin and the serum concentrations of IL-6 (r = 0.71, P < 0.05). Activin A was positively correlated with post-OST insulin concentrations (r = 0.707, P = 0.05), indicating that this marker of inflammation could warrant further investigation in horses with EMS. •Obesity and metabolic disorders are associated with systemic low-grade chronic inflammation.•Adipose tissue is not only an energy reservoir but an active endocrinological organ that can secrete adipocytokines and proinflammatory cytokines.•Hyperinsulinemia in horses is connected with circulated IL-6 serum concentration.•Insulin dysregulation in the course of equine metabolic syndrome is positively correlated with activin A concentration in horses.