Diabetes, Insulin Resistance, and Metabolic Syndrome in Horses

Abstract

Abbreviations: (CGIT) combined intravenous glucose-insulin test, (DM) diabetes mellitus, (EMS) equine metabolic syndrome, (HbA1c) glycosylated hemoglobin, (IR) AbstractAnalogous to the situation in human medicine, contemporary practices in horse management, which incorporate lengthy periods of physical inactivity coupled with provision of nutritional rations characterized by inappropriately high sugar and starch, have led to obesity being more commonly recognized by practitioners of equine veterinary practice. In many of these cases, obesity is associated with insulin resistance (IR) and glucose intolerance. An equine metabolic syndrome (MS) has been described that is similar to the human MS in that both IR and aspects of obesity represent cornerstones of its definition.Unlike its human counterpart, identification of the equine metabolic syndrome (EMS) portends greater risk for development of laminitis, a chronic, crippling affliction of the equine hoof. When severe, laminitis sometimes necessitates euthanasia. Unlike the human condition, the risk of developing type 2 diabetes mellitus and many other chronic conditions, for which the risk is recognized as increased in the face of MS, is less likely in horses. The equine veterinary literature has been replete with reports of scientific investigations regarding the epidemiology, pathophysiology, and treatment of EMS.

Insulin resistance in the horse: a review

“…Horses are at an increased risk of laminitis, and EMS is also the cause of hyperlipidaemia syndrome (hepatic lipidosis) and osteochondrosis in young horses (Johnson et al 2012). Despite a strong correlation between obesity and IR, the latter and other metabolic disorders have been reported in horses with normal body weight, but such animals are often characterized by abnormal distribution of adipose tissue (Frank 2009).…”

“…Other diseases accompanying equine obesity and IR have been rarely described (Wylie & Collins 2010;Johnson et al 2012;Tadros & Frank 2013). Type 1 diabetes mellitus (T1DM) is characterized by the lack of insulin secretion by beta cells of the pancreas as a result of their destruction (due to viral or immune-mediated disease), whereas type 2 diabetes mellitus (T2DM), characterized by relatively reduced insulin secretion, is a complex metabolic disorder that develops due to chronic hyperinsulinemia.…”

“…T2DM occurs in older horses affected with polyuria, polydipsia and body weight loss as a consequence of pituitary pars intermedia dysfunction. Cases of bona fide DM were described in adult horses (caused by chronic pancreatitis, pituitary pars intermedia dysfunction, granulosa cell tumour, immune polyendocrinopathy, and ovarian neoplasia in pregnancy) (Durham et al 2009;Johnson et al 2012).…”

“…Reduction of dietary digestible energy is an important factor in lowering body weight through the partial or complete elimination of access to pasture grass. The diet should be based on fibre-rich roughages (mostly hay) supplemented with minerals and vitamins (Frank et al 2010;Frank 2011;Johnson et al 2012). Improvement of tissue response to insulin is attributed to increased glucose uptake and utilization in muscles, the main site of insulin-dependent glucose uptake.…”

Efeitos Da Clonidina E Da Rilmenidina Sobre Os Sistemas Cardiorrespiratório E Gastrointestinal De Equinos

“…Diante do exposto, clonidina e rilmenidina podem ser úteis se aplicadas no tratamento de doenças que provoquem dores agudas e/ou crônicas associadas a quadros de hipertensão arterial, como ocorre, por exemplo, na laminite (17,18) , ou como adjuvantes quando aplicadas em protocolos de analgesia multimodal. Sabendo-se que, apesar de serem efetivos no controle da dor, alguns analgésicos atualmente utilizados podem predispor a importantes reações adversas quando utilizados por períodos prolongados, como é o caso, por exemplo, dos anti-inflamatórios não esteroidais (13) , a busca por fármacos com maior eficiência analgésica e menores efeitos colaterais se torna um desafio de impacto direto sobre a qualidade de vida e o bem-estar dos animais.…”