Publication Database

Das Equine Metabolische Syndrom – Eine Übersicht (2025)

Art

Zeitschriftenartikel / wissenschaftlicher Beitrag

Autoren

Simon, K.

Liertz, S. (WE 17)

Stöckle, S. (WE 17)

Gehlen, H. (WE 17)

Quelle

Compendium Pferdeheilkunde

Bandzählung: 1

Heftzählung: 2

Seiten: 88 – 103

ISSN: 2943-1808

Verweise

URL (Volltext): https://www.hippiatrika.com/de/fundus/schluesselwoerter/?kid=40&index=g

DOI: 10.21836/PEM20250201

Kontakt

Pferdeklinik

Oertzenweg 19 b
14163 Berlin
+49 30 838 62299 / 62300
pferdeklinik@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Equine Metabolic Syndrome is not a disease in itself, but rather a cluster of risk factors for endocrinopathic laminitis. These include insulin dysregulation, obesity, dyslipidemia, dysregulation of adipokines and cardiovascular changes. EMS is becoming increasingly prevalent and important, as a growing proportion of the horse population is overweight. Epidemiological studies have found that between 7.8% and 61% of the animals in the respective populations examined were affected. Genetic factors and the influence of housing and feeding increase the risk of the disease. Breeds with higher prevalence are ponies, gaited horses, Arabians, Andalusians, Morgans, miniature horses and warmbloods. The risk increases with age due to increasing insulin concentrations. All animals that consume too high amounts of non-structured carbohydrates over a long period of time and do not get enough exercise can be affected. As a result, insulin dysregulation develops, which can be the cause of endocrinopathic laminitis. The latter can be resistant to treatment on the one hand and can also end a horse's sporting career and, in the worst case, lead to euthanasia. The diagnostic criterion for EMS is the detection of insulin dysregulation. In response to postprandial hyperglycemia, the pancreas secretes insulin physiologically. This is additionally stimulated by factors of the enteroinsulin axis. At the target cells in the liver, muscles and fatty tissue, insulin then mediates the uptake of glucose. If this effect is impaired in the tissue, insulin resistance is present. In patients with EMS, there is a lower density of insulin receptors on the cell surface and a reduced expression of glucose transporters. Insulin resistance can often be compensated for for a long time by hyperinsulinemia, either due to excessive insulin secretion and/or reduced clearance. In addition to general obesity, regional obesity with excessive fat deposits along the crest of the neck (cresty neck), at the base of the tail, caudal to the shoulder and pre-putial or premammillary can also be observed. At the same time, the amount of visceral fat increases in an invisible way. EMS leads to disturbances in fat tissue metabolism and dysregulation of adipokines. Both promote a pro-inflammatory metabolic situation. Over the long term, obesity leads to increased triglyceride concentrations and increased concentrations of non-esterified fatty acids (NEFA). Insulin resistance also increases triglyceride production and lipolysis. Obesity is an aggravating factor for insulin dysregulation. Insulin plays a causal role in the development of laminitis. The severity increases with increasing plasma levels. The current theory is that hyperinsulinemia leads to inadequate stimulation of the insulin-like growth factor-1 receptor in the lamellar tissue. This leads to proliferation and keratinization and ultimately to separation of the epidermis and dermis. At the beginning, the inflammation is minimal, so that only mild clinical symptoms such as tenderness, diverging horn rings or a widening of the white line occur. Similar to human medicine, horses with EMS have been shown to have a reduced vasodilatory response and cardiovascular changes such as high blood pressure and left ventricular hypertrophy. The animals have impaired thermoregulation and are often insufficient in terms of performance. Obesity and insulin resistance affect the cycle and the quality of the oocytes. Affected mares are often subfertile. During pregnancy, insulin sensitivity continues to decrease and thus the risk of laminitis increases. In foals, the maternal disease promotes orthopedic malformations, OCD and changes in the pancreas. In a clinical examination, body condition is assessed by weighing, tape measures or semi-quantitative scoring methods. Regional obesity is strongly associated with elevated insulin concentrations and is assessed using the Cresty Neck Score (CNS) according to CARTER. The hooves are examined for signs of abnormal growth and tenderness and are X-rayed. In addition to the clinical examination, the diagnosis requires detailed laboratory diagnostics. Determining the basal insulin concentration is not very suitable for diagnosing insulin dysregulation. The time of day and year, feeding, enteral absorption capacity, physical activity, hormone fluctuations, gender, breed, age, stress and sedation have a strong influence on basal insulin concentrations and insulin sensitivity. Dynamic tests are therefore recommended to detect both hyperinsulinemia with the associated risk of laminitis and the insulin sensitivity of the peripheral tissue. In practice, oral sugar tests in various variants are suitable for assessing the postprandial insulin response. An insulin tolerance test directly examines the insulin-dependent glucose uptake in the tissue. Insulin values from different laboratory analysis methods cannot be directly compared with one another, but must be converted. Further information on insulin status and lipid regulation is provided by determining the concentrations of triglycerides and free fatty acids. Examining adiponectin helps to assess the risk of laminitis. PPID can be present at the same time and can further exacerbate insulin dysregulation. It should therefore also be examined diagnostically. The basis of the therapy is a reduced diet consisting of controlled amounts of hay with a low content of non-structured carbohydrates (< 10%) and supplementation with mineral feed and protein. The aim is to reduce body mass by 0.5 - 1% per week until a BCS of 5/9 is achieved. If the laminitis status allows, an adapted and progressive exercise program is recommended. Regular (5 - 7 x/week) exercise with heart rates of 130 beats/min or more for at least 30 minutes has a significant effect on insulin sensitivity. If these measures prove insufficient, a temporary concomitant drug therapy can be initiated. Levothyroxine increases the metabolic rate and can accelerate the success of the diet. Metformin reduces glucose absorption in the intestine, but appears to have very different effects on each individual. Pioglitazone increases insulin sensitivity, but has not been studied much in horses. The use of ertugliflozin, dapagliflozin and canagliflozin is increasingly being reported from the new class of oral active substances, the sodium-glucose cotransporter 2 inhibitors (SGLT-2i). Velagliflozin has been studied in experimental studies in horses with good results. In horses that also suffer from PPID, appropriate therapy with pergolide is recommended. This can improve insulin regulation. The long-term management of a patient with EMS requires permanent adjustments of feeding and housing conditions under veterinary supervision.