Clinical Research Abstracts of the British Equine Veterinary Association Congress 2015.

Abstract

REASONS FOR PERFORMING STUDY: Andalusian horses have been proposed as a breed predisposed to equine metabolic syndrome (EMS) phenotype [1] because they are prone to exhibiting regional, generalised adiposity and tendency to laminitis [2]. Insulin dysregulation represents the main pathophysiological cause for all the features of EMS, however there are no epidemiological studies in this breed. OBJECTIVE: To assess insulin dysregulation through insulin proxies in Andalusian horses with different levels of obesity. STUDY DESIGN: Cross-sectional study. METHODS: One hundred and sixty-four Andalusians (78 stallions and 86 mares, 2-15 years) were scored for overall (body condition score, BCS) and neck (cresty neck score, CNS) adiposity. Grain concentrate was withheld for 12&#x2009;h before sampling. Blood samples were collected between 06.00-10.00&#x2009;h for basal glucose, insulin concentrations, RISQI and MIRG proxies calculation. Conditions were defined as: obese horses (Ob), BCS&#x2009;&#x2265;&#x2009;7; cresty neck horses (CN), CNS&#x2009;&#x2265;&#x2009;3; hyperinsulinaemia, insulin &#x2265;20&#x2009;&#x3bc;u/ml; low insulin sensitivity, RISQI<0.32[mu/l](-0.5) and increased insulin secretory response, MIRG>5.6muinsulin (2)/[10.l.mgglucose]. Regarding BCS 2 groups were created: Ob and non-Ob. These groups were subdivided depending on CNS: with CN and without it (nonCN). Ob-nonCN group (n&#x2009;=&#x2009;2) was excluded for the statistics due to the low number of horses. RESULTS: Of the horses studied, 26.8% were Ob-CN, 42.1% were nonOb-CN and 31.1% were nonOb-nonCN. Ob horses presented higher insulin levels (P&#x2009;=&#x2009;0.034) and lower RISQI values (P&#x2009;=&#x2009;0.019) than all nonOb horses. When CN was considered, only RISQI was lower (P&#x2009;=&#x2009;0.015) in Ob-CN group respect to nonOb-nonCN, however nonOb-CN group does not differ from the other 2 groups. Furthermore, the percentage of Ob-CN horses with hyperinsulinaemia (2.3%), abnormal RISQI (4.5%) and MIRG (9.1%) was very low. CONCLUSIONS: These results suggest that in Andalusians, increased adiposity was not clearly associated to insulin dysregulation and, similar to human beings, may coexist as a metabolically healthy but obese phenotype. Ethical animal research:&#x2002;Ethical University Committee approved all the procedures and owner informed consent was obtained. SOURCE OF FUNDING: None. Competing interests:&#x2002;None declared.