Relationships between total adiponectin concentrations and obesity in native-breed ponies in England

Barnabe, Marine; Elliott, Jonathan; Harris, Patricia; Menzies-Gow, Nicola

Abstract

Background: Equine metabolic syndrome is a collection of risk factors associated with an increased risk of endocrinopathic laminitis. All affected animals display insulin dysregulation and some may show adiponectin dysregulation and/or excessive adiposity. However, the relationship between obesity and hypoadiponectinemia in equids remains unclear.
Objectives: To investigate the relationship between obesity and circulating plasma total adiponectin (TA) concentrations in native-breed ponies in the UK.
Study design: Retrospective data analysis.
Methods: Data collected for three previous studies were retrospectively analysed and cohorts were pooled where possible (maximum sample size: n=734 ponies). Correlations between [TA], age, and morphometric measures were assessed using Spearman’s correlation coefficient. [TA] was compared between animals of different body condition score (BCS) classification (ideal-weight, overweight, and obese), breed, and body shape using Kruskal-Wallis and Dunn’s post-hoc test, and sex using Mann-Whitney U test. The proportions of obese and ideal-weight ponies with basal hyperinsulinemia and/or hypoadiponectinemia were compared using a Chi-square test of homogeneity and post-hoc z-test. Logistic regression was used to identify factors that may discriminate ponies with hypoadiponectinemia.
Results: [TA] was weakly positively correlated with BCS, height, weight, and weight:height ratio (Spearman’s ρ = 0.144–0.293). There were significant differences in [TA] in ponies with different BCS group classification, body shape, and breed. A greater proportion of obese (54.6%) than ideal-weight ponies (33.1%, P<0.001) had normal [TA] and [basal insulin], and a greater percentage of ideal-weight (38.6%) than obese ponies (16.5%, P<0.001) showed hypoadiponectinemia. Height, weight, weight:height, and BCS group were significant variables in a logistic regression of hypoadiponectinemia but model fit and predictive accuracy were poor.
Main limitations: Retrospective study design, only native-breed ponies included.
Conclusions: Morphometric measures such as BCS do not closely reflect [TA]. Circulating [TA] and [basal insulin] should be determined in all animals with predisposing factors, regardless of obesity status.

Citation

Barnabe, M., Elliott, J., Harris, P., & Menzies-Gow, N. (in press). Relationships between total adiponectin concentrations and obesity in native-breed ponies in England. Equine Veterinary Journal, https://doi.org/10.1111/evj.14013

• Journal Article Type: Article
• Acceptance Date: Sep 7, 2023
• Online Publication Date: Jan 6, 2023
• Deposit Date: Jan 17, 2024
• Publicly Available Date: Jan 17, 2024
• Print ISSN: 0425-1644
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1111/evj.14013