A eficácia do exercício aeróbico na prevenção da aterosclerose experimental em coelhos albinos (oryctolagus cuniculus) submetidos à dieta hiperlipídica

Abstract

Introduction: Coronary artery disease (CAD) has been the leading cause of death in Brazil, followed by stroke over the past thirty years, and has also been responsible for the increase in the number of hospitalizations in the SUS. Its pathophysiological basis is atherosclerosis. Physical exercise promotes effects that result in a decrease in the incidence of cardiovascular events, being a measure for the prevention and treatment of atherosclerosis and dyslipidemia. The recommendation and prescription of physical exercise by several health professionals is a common situation, however there is a need for simpler, cheaper and easy-to-apply ways to determine its effectiveness in preventing atherosclerosis. Objective: To determine the effectiveness of aerobic exercise in preventing experimental atherosclerosis in male albino rabbits (Oryctolagus cuniculus) subjected to a high-fat diet. Material and Method: Fifteen male albino New Zealand rabbits were randomly distributed into three groups of five animals, namely: Control Group (G1), whose animals received food and water ad libitum; Yolk Group (G2), food and water ad libitum, plus 20 ml of chicken egg yolk divided into two administrations per day; and Exercise Group (G3), which, in addition to the 20 ml of yolk, performed an aerobic exercise protocol five days a week, at moderate intensity, for 60 minutes per day, on a motorized treadmill for human use adapted with an MDF corral, as well as food and water ad libitum. Blood was collected at four times (initial, 33, 66 and 99 days) to check the lipid profile, and after the 99th day of the experiment, the animals were euthanized for removal of the aortic arch and histological, morphometric and immunohistochemical analysis. For analysis of continuous variables, data were described using mean and standard deviation, as well as median and interquartile range. The Shapiro-Wilk normality test was initially performed to verify data distribution. In the case of normal distribution, the one-way ANOVA test with Bonferroni's post-test was performed; for abnormal distribution, the Kruskal-Wallis test with Dunn's post-test was performed. Results: The exercise group presented less thickening of the subendothelial layer and the media layer than the Yolk group; it presented lower levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL) and better levels of high-density lipoprotein (HDL) and also lower expression of the CD68 marker. The values of the means of the size of the thickening of the subendothelial layer of the Yolk and Exercise Groups were placed in a simple rule of 3 to obtain a percentage. Conclusion: Aerobic exercise is effective in preventing experimental atherosclerosis. Its efficacy is 18% in reducing subendothelial layer thickening. Group G3 showed improved lipid profile values and lower expression of the inflammatory marker CD68 compared to group G2. Therefore, aerobic exercise is an effective method of preventing atherosclerosis, acting strongly on the arterial wall, improving its morphological and morphometric aspects, especially the endothelium. Its practice may be the key to achieving better vascular health conditions.