High-intensity interval training ameliorates high-fat diet- induced elevation of aminotransferases in male Wistar rats

Background and aims: A high-fat diet increases triglyceride (TG) accumulations in hepatocytes and results in non-alcoholic fatty liver diseases (NAFLDs). In this regard, this study investigated the effect of high-intensity interval training (HIIT), along with a high-fat diet on the serum levels of aminotransferases in male Wistar rats. Methods: Forty male Wistar rats were randomly assigned to the standard diet, high-fat diet, exercise + standard diet, and exercise + high-fat diet groups (each containing 10 animals). HIIT program consisted of 6-12 repetitions of 2-minute highs-intensity exercise (85-90% of the maximum speed) interspersed with 1-minute low- intensity exercise (45-50% peak speed) with the frequency of 5 sessions a week over 12 weeks. High-fat diet groups received a diet regimen including 58% fat, 25% protein, and 17% carbohydrate, ad libitum. The blood samples were taken from the left ventricle 48 hours following the last intervention to assess TG, alanine aminotransferase (ALT), and aspartate amino-transferase (AST) concentrations. Data were analyzed using one-way ANOVA and Tukey’s post - hoc tests. Results: The findings showed the mean of ALT, AST, and TG in the high-fat diet group was significantly greater compared to the standard diet group (P = 0.001). Furthermore, the mean of ALT, AST, and TG in the exercise + high-fat diet group was significantly lower in comparison with the high-fat diet group (P = 0.01, P = 0.017, and P = 0.012, respectively). Conclusion: Although HIIT ameliorated high-fat diet- induced elevations in the serum levels of TG, ALT, and AST, they did not reach the baseline levels. Thus, it may indicate that a diet as the underlying cause of NAFLDs is more important than any other interventions such as exercise.