Search

The mechanism related to the practice of oral carbohydrate (CHO) supplementation prior to intense exercise of a short duration (

Riders and trainers believe that oral maltodextrin (MD) supplementation prior to exercise increases blood glucose availability and delay the onset of fatigue in horses, although there is no evidence supporting this claim. Therefore, we aimed to evaluate the effect of MD supplementation on blood glucose, L-lactate, insulin, and cortisol levels and heart rate in horses subjected to an incremental exercise test. A randomized placebo-controlled crossover trial was designed to test the effect of three doses of MD (50 g, 100 g and 200 g) on blood glucose, L-lactate, insulin, and cortisol levels and heart rate of four Purebred Lusitanian geldings. A seven-step incremental field exercise test was used; the initial speed was set at 2.5 m/s, followed by 3.3 m/s, 4.1 m/s, 5.0 m/s, 6.6 m/s, and 8.4 m/s. There was a significant influence of exercise itself on plasma glucose and L-lactate concentrations and on heart rate (p < 0.05), whereas the amount of MD administered changed only the cortisol levels (p < 0.05). During rest and exercise, the variables remained within the normal reference range for stalled and exercising horses, respectively. Blood glucose levels in the placebo group at rest, 5.0 m/s, and 8.4 m/s were 87.63 ± 3.25 mg/dL, 78.33±10.08 mg/dL, and 95.18 ± 14.73 mg/dL, respectively, whereas those for the group supplemented with 200 g MD were 99.25±12.19 mg/dL, 79.55±13.81 mg/dL, and 97.30 ± 16.46 mg/dL, respectively. The mean cortisol levels in the placebo and 200 g MD groups at 8.4 m/s were 1.20 ± 0.53 mmol/L and 5.54 ± 4.73 mmol/L, respectively. In conclusion, MD supplementation increased serum cortisol levels and showed no effect on heart rate, blood glucose, L-lactate and serum insulin levels of horses submitted to an incremental exercise test.

A resistência à insulina é um problema cada vez mais presente na rotina clínica dos veterinários que trabalham com equídeos. A hiperinsulinemia resultante da resistência à insulina está associada a diversas alterações fisiológicas e podem levar a enfermidades graves como a Síndrome Metabólica Equina ou a Laminite que podem culminar na invalidez ou até morte do animal. O diagnóstico da resistência à insulina em equinos é baseado em modelos dos mesmos testes realizados em humanos. Até a presente data não há testes práticos, acessíveis e com sensibilidade e especificidade suficientemente capazes de diagnosticar a resistência à insulina em equinos. Em humanos e outros modelos animais a frutosamina é um biomarcados utilizado no diagnostico da resistência a insulina. A dosagem de frutosamina sérica é simples e barata, porém, seu uso no diagnostico da resistência à insulina em equinos ainda não foi testado. O presente estudo tem como objetivo avaliar a frutosamina em cavalos estabulados e sedentários diagnosticados com resistência à insulina por três diferentes métodos descritos em literatura sendo estes: Teste Combinado de Glicose e Insulina, Reciproco da Raiz Quadrada da Insulina (RRQI) e Relação Glicose-Insulina Modificada (RGIM). Além disso avaliamos a incidência de resistência à insulina em cavalos estabulados e sedentários. Todos os testes foram capazes de identificar grupos resistentes e não resistentes a insulina, porém com baixo concordância entre si. Apesar disso a dosagem de frutosamina sérica não diferiu entre os grupos formados a partir de qualquer um dos métodos diagnósticos de resistência à insulina. Insulin resistance is an increasing problem in the clinical routine of equine veterinarians. The hyperinsulinemia resulting from insulin resistance is associated with several physiologic alterations and can lead to serious diseases like equine metabolic syndrome or laminitis which can to early retirement or animal death. Equine insulin resistance diagnosis is based in human tests. Until now, there is no practical, accessible, sensible and specificity test capable of diagnosing equine insulin resistance. In human and other animals model, frutosamine is simple and cheap biomarker use in this diagnosis, however its use for equine insulin resistence diagnosis never had been tested. The aim of the present study was to evaluate the fructosamine in stable and sedentary horses diagnosed with or without insulin resistance by three different methods described in the literature (Combined Glucose and Insulin Test - TCGI, Reciprocal of the Square Root of Insulin (RISQI) and Modified Insulin-to-Glucose Ratio (MIRG). For this, 17 adult male horses were evaluated. All tests were able to identify resistant and not resistant to insulin animals, but with low concordance between them. Regardless of the test used, the serum fructosamine dosage did not differ between the resistant and non-insulin resistant groups and could not be used as an early marker for insulin resistance in horses.