The effect of aerobic, resistance, and combined training on PPAR-α, SIRT1 gene expression, and insulin resistance in high-fat diet-induced NAFLD male rats

Background: Insulin resistance (IR) is known as the most important cause of Non-alcoholic Fatty Liver Disease (NAFLD), which is accompanied by a decline in gene expression of hepatic's peroxisomes Proliferator-Activated Receptors-alpha (PPAR-alpha) and Sirtuin-1 (SIRT1). This study aimed to investigate the effect of eight weeks of aerobic, resistance, and combined training on hepatic PPAR-alpha and SIRT1 expression, IR, serum Alanine aminotransferase (ALT), and aspartate aminotransferase (AST) in rats of NAFLD induced by high-fat diet (HFD). Methods: A total of 37 male NAFLD rats induced 12 weeks of HFD were randomly divided into 4 groups: control, aerobic, resistance, and combined training. All groups continued the HFD until the end of the study. The training groups carried out exercise training with moderate intensity by 8 weeks of running on a treadmill and climbing a ladder for 5 sessions/week. At the end of the trainings, PPAR-alpha and SIRT1 expressions were examined via qPCR technique in the liver tissue. Results: The 3 types of trainings controlled the weight gain caused by HFD and showed a significant decrease in serum ALT (P<0.05). Post-hoc test results indicated a significant reduction in AST and IR between the control group and HFD+AT, as well as the control group and HFD+RT (P<0.05). Despite a notable increase in hepatic PPAR-alpha and SIRT1 expression, it was not statistically significant (P >= 0.05). Conclusion: Doing any aerobic, resistance, and combined training for 8 weeks can control body weight, improve IR, decrease ALT; nevertheless, resistance training is more effective in improving NAFLD.