Treinamento intervalado de alta intensidade promove controle pressórico, melhora a tolerância ao exercício e função cardíaca em ratos espontaneamente hipertensos

Abstract

Introduction: Systemic Arterial Hypertension (SAH) is a serious public health problem, especially for the elderly, and can lead to concentric hypertrophy an important risk factor for heart failure, which is considered a predictor of increased cardiovascular morbimortality. Studies have shown that High Intensity Interval Training (HIIT) may also be indicated for hypertensive patients. However, to the authors’ knowledge, no studies have evaluated HIIT in cardiac remodeling of animals with systemic arterial hypertension. Objective: to evaluate in spontaneously hypertensive rats (SHR) submitted to HIIT, pressure control, exercise tolerance and cardiac remodeling. Methods: 20 SHR rats were divided into two groups: sedentary (SHR-SED, n= 9) and HIIT training (SHR-HIIT, n= 11); and Wistar Kyoto rats composed the control group (WKY, n= 6), 12 months of age. The animals were familiarized with HIIT for a week with 10 minutes on the treadmill adapted for rodents. An incremental stress test was performed to exhaustion to adjust exercise intensity. The HIIT was performed five times a week for eight weeks. Before and after HIIT, blood pressure (BP) was measured by plethysmography and a maximal exercise capacity test was performed. Cardiac remodeling was assessed through echocardiography and after euthanasia, the isolated papillary muscle was evaluated. For comparison between groups, we used ANOVA followed by the Tukey test or Kruskal-Wallis and Dunn tests (p <0.05). Results: HIIT decreased the variation (Δ%) of SBP (SHR-SED=Δ% 12.5 vs. SHR-HIIT=Δ% -4.34; p = 0.005), increased the distance traveled, being 82.7% higher in the SHR-HIIT group (SHR-SED=183.0±88.08m; vs. SHR-HIIT=1126.0±187.1m; p<0.001) and reduced the resting tension of the papillary muscle (WKY=0.77 ± 0.216; SHR-SED=1.26 ± 0.20; SHR-HIIT=0.67 ± 0.23; p=0.0001). Conclusion: In SHR rats, HIIT decreased BP variation, improved functional capacity and ameliorated pathological cardiac remodeling.