Razi Journal of Medical Sciences

Background & Aims: Sedentary lifestyle is associated with unhealthy health consequences, especially overweight and obesity, and obesity is associated with an increased risk of metabolic syndrome (1). Numerous studies have shown that visceral adipose tissue plays an important role in the development of metabolic syndrome (4, 5). Uncontrolled production of adipocytokines is involved in the pathogenesis of obesity-related metabolic syndrome (7).
Studies showed that regular physical activity is a good way to reduce the symptoms of metabolic syndrome (18, 19). high-intensity interval training has been reported to burn more calories and increase fat oxidation, as well as more energy expenditure than continuous exercise (steady state) (21). However, the results of studies the effect of HIIT on resistin are contradictory (22, 23). Also following HIIT, were reported decrease (24, 25) and no significant change (26) of PAI-1. There is a lot of ambiguity about the most appropriate training method to control adipokine activity in people with the metabolic syndrome. It is expected that by conducting the present study, while answering some of the ambiguities in determining the effect of high-intensity interval training program on the biochemical process of metabolic disorders, it will be possible to make appropriate suggestions on how to perform exercise and predict possible consequences. Therefore, the present study intends to investigate the effect of 6 weeks high-intensity interval training on the gene expression of PAI-1 and resistin visceral fat in rats with metabolic syndrome.
Methods: This is an experimental study. This research was conducted on Wistar rats in at Baqiyatallah University of Medical Sciences, Tehran, Iran. thirty-two rats (weighing 180± 20 gr) were selected and randomly divided into 4 groups including control, metabolic syndrome, High-Intensity Interval Training and metabolic syndrome + High-intensity interval training. Rats were randomly divided into two groups: standard diet and high fat diet (HFD: High Fat Diet), then next to the group with standard diet, rats in the high fat diet group for 12 weeks. They underwent a special diet (30 to 40% fat) to develop a model of metabolic syndrome, and after 12 weeks, blood samples (fat profile, insulin resistance, fasting glucose) were taken from this group to Confirm of model the disease (27). High-Intensity Interval Training consisted of 5 to 10 interval 1-minute intensive running on the treadmill at 80 to 95% of maximum speed and in slow alternations at 55% of Maximum speed with zero treadmill slope. gene expression of PAI-1 and resistin in visceral fat was measured after training using Real Time PCR.
Results: The results showed that PAI-1 and resistin gene expression levels were higher in rats with metabolic syndrome than the other groups. Six weeks of High-intensity interval training significantly decreased the expression of resistin and PAI-1.
Conclusion: The findings of this study were consistent with the results of Previous research (14, 24, 25). A possible cause of decreased PAI-1 activity in this study could be reduced adipose tissue in rats that performed high-intensity interval training. Also, it is possible that exercise reduces the production of PAI-1 by inhibiting NF-Kb protein transcription. In the present study, possible causes of reduction in resistin were weight loss, fat percentage and the ability of HIIT to upset energy balance. Some researchers have reported decrease in resistin due to decrease in inflammatory cytokines such as IL-6, TNF, and IL-1 (38). It is recommended that high-intensity interval training be considered in the treatment programs of patients with metabolic syndrome. In the present study, there were limitations in the present study, including the study of animal specimens. Other limitations of this study include lack of measurement of other adipokines associated with the pathogenesis of metabolic syndrome. According to the results, it seems that obesity and visceral adipose tissue can increase the rate of resistin and PAI-1 gene expression and decrease high-intensity interval training.