The effect high-intensity interval training on FGF-21 expression in flexor hallucis longus muscle and serum TNF-α levels in diabetic rats

Type 2 diabetes is one of the metabolic diseases that is associated with partial or absolute insulin deficiency, high blood glucose and disorders of carbohydrate, fat and protein metabolism. This condition is characterized by a persistent rise in blood sugar and can be caused by a disorder in the secretion or action of insulin, or both. Metabolic pattern imbalance, insulin resistance, and increased levels of inflammatory markers have been reported in diabetic patients. The effects of diabetes threaten the lives of millions of people around the world every year. A healthy lifestyle, proper nutrition and regular exercise are the most important factors in preventing or reducing the effects of diabetes. main imperfection in the pathology of type 2 diabetes include insulin resistance in muscle and liver. Skeletal muscle is considered to be the largest organ in the body in non-obese individuals, and as an active endocrine organ it releases myokines. Myokines have systemic effects on the liver, adipose tissue, brain and immune system. They can be effective in regulating metabolic and inflammatory processes. Fibroblast growth factor-21 is known as a member of the family of fibroblast growth factors and has recently been introduced as a factor in regulating the metabolic process.Because diabetes medications have many limitations, including high cost, and side effects, many strategies have been proposed to control insulin and reduce insulin resistance in diabetes. Regular exercise and following a healthy diet is a good strategy to treat and reduce costs in many metabolic disorders, including type 2 diabetes and obesity. High-Intensity Interval Training has recently been considered as a suitable training option, not only among athletes but also among those who are limited in time. Exercise reduces inflammation and reduces cell death caused by diabetes in the bodychr('39')s cells by activating intracellular and extracellular pathways. Increased myokines due to exercise can be effective in regulating metabolic and inflammatory processes. The aim of this study was to investigate the effect of 6 weeks of High-Intensity Interval Training on FGF21 Expression in Flexor Hallucis Longus muscle tand serum TNF-α Levels of diabetic rats.

In this experimental study, 48 Wistar male rats weighing 150±10g were randomly divided into 4 groups of Diabetes (n = 10), Control (n = 10), Diabetes +Training (n = 12) and Training (n = 12). All animals were kept in separate cages under the similar conditions. In this study, For induction of experimental diabetes Wistar rats received streptozotocin as a single dose of 50 mg / kg body weight by intraperitoneal injection. The training program consisted of 10 sets of 1 minute running (2 minutes rest between each set) on a treadmill with gradually increasing speed and incline, for 6 weeks and 3 training sessions per week. Running speed gradually increased from 18 to 31 m / min over 6 weeks and the treadmill slope increased from 2 to 10 ° (50 to 110% VO2max). At the end of the sixth week, after FHL muscle tissue sampling, FGF-21 gene expression was measured by Real time PCR and serum TNF-α level was measured by ELISA using Diaclone kits from France. In the inferential statistics section, Shapiro-Wilk test was used to the normality of data. equality of variances with Levene test was also measured. Findings were evaluated at a significance level of 95% (p <0.05). SPSS software version 22 was used for statistical analysis of data.

The results showed that 6 weeks of High-Intensity Interval Training did not have a significant effect on FGF-21 gene expression of FHL muscle in diabetic rats (p = 0.095). However, the reduction of inflammation and inflammatory factors such as TNF-α was shown due to High-Intensity Interval Training (p = 0.000).

Considering all the above and also the results of statistical analysis, it was found that High-Intensity Interval Training has no significant effect on the expression of FGF-21 gene in FHL muscle tissue of diabetic rats. But regular exercise, in addition to weight control, has anti-inflammatory effects and suppresses systemic inflammation and muscle atrophy. Tnf-α is one of the major pro-inflammatory cytokines that causes inflammation. The results of the present study showed that High-Intensity Interval Training reduces the negative effects of diabetes on the cardiovascular system and health by activating various cellular and molecular pathways and mechanisms. Serum Tnf-α levels, which are a factor in pro-inflammation and apoptosis, are reduced by High-Intensity Interval Training. However, much research is needed to substantiate the above results. In addition, High-Intensity Interval Training can be used as a therapeutic approach to diabetes management for patients who are unable to perform continuous exercise for a variety of reasons.