Evaluation of the combined glucose-insulin and intravenous glucose tolerance tests for insulin dysregulation diagnosis in donkeys.

Francisco Javier Mendoza,Ben R Buchanan,Alejandro Perez‐Ecija,Sebastian Mejia‐Moreira,Ramiro E Toribio

doi:10.1111/evj.13482

Francisco Javier Mendoza, Ben R Buchanan + Show 3 more

Open Access

https://doi.org/10.1111/evj.13482

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Abstract

Insulin dysregulation (ID) and donkey metabolic syndrome (DMS) are common in this species. Contrary to horses, diagnostic guidelines compiling insulin cut-offs values and dynamic testing interpretations have not been reported for this species. To evaluate resting serum insulin concentrations, the combined glucose-insulin test (CGIT) and the glucose intravenous tolerance test (IVGTT) for the diagnosis of DMS with ID suspicion. Diagnostic test comparison. Six of 80 mix-breed adult donkeys fulfilled the inclusion criteria for DMS based on history or clinical evidence of recurrent laminitis, body condition >6 and neck score >2 or baseline insulin and leptin concentrations >20µIU/mL and >12ng/mL respectively. CGIT and IVGTT were performed in all donkeys within a week and interpreted following guidelines reported for equine metabolic syndrome (EMS). Insulin and glucose curves were analysed, proxies calculated and correlations and multivariate analysis assessed. Following EMS guidelines, CGIT classified 2 (using glucose-positive phase duration) or 3 (using insulin concentration) and IVGTT classified 5 donkeys as ID. ID donkeys showed a lower glucose/insulin ratio, QUICKI and RISQI, and a higher insulin/glucose ratio, MIRG and HOMA-B%. Comparison of these tests with additional dynamic testing including a larger number of ID donkeys is necessary. This is the first study evaluating dynamic tests to assess ID/DMS in DMS-suspected donkeys. IVGTT detected more ID donkeys than CGIT. EMS recommendations could also be used for DMS diagnosis, although a baseline insulin cut-off value is needed.

Highlights

Interest in donkeys has been increasing in recent years in developed countries, in particular related to assisted therapies for people with psychomotor and mental disabilities, as an alternative source of milk for people with cow's milk intolerance, in certain sport competitions and as companion animals.[1]
Donkeys are afflicted by similar pathologies as horses; due to physiological and pharmacological differences between donkeys and horses,2-4 a species-specific approach should be considered when dealing with diagnostics and therapies in donkeys
Most research on insulin dysregulation (ID) has been on the diagnosis of equine metabolic syndrome (EMS), with guidelines being updated frequently.13-15 The body condition score (BCS) and baseline insulin, triglyceride, leptin and/or adiponectin concentrations are used in the diagnosis and management of EMS.[16,17]

Summary

| INTRODUCTION

Interest in donkeys has been increasing in recent years in developed countries, in particular related to assisted therapies for people with psychomotor and mental disabilities, as an alternative source of milk for people with cow's milk intolerance, in certain sport competitions and as companion animals.[1]. Donkey/Asinine metabolic syndrome (DMS or AMS) is a frequent endocrinopathy in this species. Most research on insulin dysregulation (ID) has been on the diagnosis of EMS, with guidelines being updated frequently.13-15 The body condition score (BCS) and baseline insulin, triglyceride, leptin and/or adiponectin concentrations are used in the diagnosis and management of EMS.[16,17] the value of these clinical, metabolic and endocrine parameters in the diagnosis of DMS remains unclear. We hypothesised that donkeys have specific glucose and insulin disposal particularities that could misdiagnose the DMS diagnosis if equine reference values are used. The objective of this study was to evaluate two of the commonly used dynamic tests for the diagnosis of EMS (CGIT and IVGTT) in DMS- suspected donkeys

| MATERIALS AND METHODS

Findings

| DISCUSSION