Influência da associação entre suplementação com creatina e exercício físico intervalado sobre metabolismo glicêmico e indicadores de remodelação cardíaca em ratos

Abstract

INTRODUCTION: Some studies have shown that creatine supplementation may lead to hyperinsulinemia and / or hyperglycemia. This, in turn, constitutes a risk factor for cardiovascular diseases. OBJECTIVES: To evaluate the influence of the combination between creatine supplementation and interval exercise on glycemic metabolism and morphological indicators of cardiac remodeling in rats. METHODS: Male Wistar rats (n = 60) were divided into four groups: control (C), creatine (Cr), physical exercise (Ep) and exercise + creatine (ECr). Group C and Ep were treated with standard commercial diet and the animals of the Cr and ECr groups received chow + 2% of creatine. The animals Ep and ECr were submitted to high intensity interval exercise protocol, 5x per week, for 12 weeks. At the end of the experiment, nutritional and murinometric behavior, functional capacity, glucose and insulin tolerance, serum biochemical profile, macroscopic and microscopic left ventricular cardiac morphology were analyzed. Two-way ANOVA was used for the glycemic tolerance analysis in the Bonferroni model of repeated measurements and multiple comparisons. For the other variables, two-way ANOVA with post hoc of Tukey was applied. RESULTS: In the evaluation of functional capacity, the rats submitted to the exercise presented greater tolerance to the effort The area under the glucose tolerance curve was lower in Ep and ECr than in C and Cr, respectively. On the other hand, the area under the insulin tolerance curve was lower in Ep than in C and ECr. The mass of the atria and the mass ratio of the atria / body mass were higher in ECr than in Ep In addition, atrial mass / body mass was higher in Cr than in C. The total body / body mass ratio was higher in ECr than in Cr and Ep. The left ventricular (LV) and right ventricular mass (RV) were similar between the groups. The cross sectional area of the cardiomyocytes (C: 227 ± 26, Cr: 216 ± 22, Ef: 284 ± 27, ECr: 297 ± 7 μm2) and the interstitial fraction of LV collagen (C: 1.96 ± 1.79, Cr = 1.98 ± 1.28, Ef: 2.36 ± 2.0, ECr: 2.49 ± 1.8%) were higher in the Ep and ECr groups than in C and Cr, respectively. CONCLUSION: In the metabolic context, high intensity interval physical exercise improves glycemic and insulinemic tolerance, but creatine supplementation reduces insulin tolerance in exercised rats. Already in the context of cardiac remodeling, high intensity interval physical exercise promotes cardiomyocyte hypertrophy and interstitial fibrosis in the myocardium of rats, without significant effect of creatine supplementation.