Extended Abstract
Introduction
Diabetes mellitus is a chronic endocrine disease accompanied by persistent hyperglycemia. Moreover, it often results in an absolute or partial deficiency of insulin secretion or insulin resistance [1]. The liver is an effective organ in protecting the blood glucose level in the normal range; increased blood glucose level leads to an imbalance of oxidation-reduction in the reactions of liver cells [5]. Increased hepatic enzymes have been suggested as predictors of diabetes. Diabetes increases the level of hepatic enzymes in the blood [6]. Resistin is also among the adipokine families produced by adipose tissue, and inflammatory cells, such as macrophages and hepatic stellate cells [8]. Furthermore, chemerin is another adipokine family member, i.e., produced by the liver and adipose tissue [15]. There exist numerous contradictions in the outcomes of the training methods. Besides, the mechanism of useful effects of these approaches on the subject of the present study remains unclear. Therefore, it is important to evaluate the implementation of different sports activities in preventing and improving the lateral complications of diabetes by controlling the related indicators. Thus, this study aimed to investigate the effect of resistance exercise training on the improvement of inflammatory indexes of liver, chemerin, resistin, and insulin resistance index in healthy and type 2 diabetic male rats.
Materials and Methods 
The present study samples were 40 male Wistar rats with a Mean±SD weight of 200±48 g. They were randomly divided into 4 groups of normal control (n=10), diabetic control (n=10), diabetic resistance training (n=10), and normal resistance training (n=10). Both diabetic resistance and training normal resistance training groups performed regular resistance training for 10 weeks by ladders. The resistance exercise consisted of 10 weeks and 5 weekly sessions of climbing a 1-meter ladder with 26 steps. Exercises were performed 3 times in 4 repetitions and 3 minutes of rest between turns and approximately 10 seconds of rest between repetitions [15]. Forty-eight hours after the last training session, all rats were anesthetized and sacrificed by chloroform injection. Blood samples were directly collected from the heart of rats. Serum levels of liver enzymes, chemerin, resistin, and insulin were calculated by the ELISA method. Additionally, the insulin resistance index was calculated by HOMA-IR formula. The normality of data distribution was tested by the Shapiro-Wilks test and the equality of variance assumption was established using Levene’s test. Next, Analysis of Variance (ANOVA), Tukey posthoc test, Analysis of Covariance (ANCOVA), and Bonferroni posthoc test at P<0.05. All statistical analyzes were performed using SPSS.
Results
Diabetes induction significantly increased fasting blood glucose and insulin HOMA-IR in the diabetic control group, compared to the healthy control group (P‏‏<0.05). The serum levels of chemerin were significantly reduced in the diabetic resistance training group, compared to the diabetic controls (P=0.04); however, it provided no significant change in them, compared to the healthy controls (P=0.181). Moreover, the serum level of resistin was significantly reduced in the diabetic resistance training group, compared to the diabetic controls (P=0.004); however, it demonstrated no significant change in them, compared to the healthy controls (P=0.062). Moreover, the serum levels of liver enzymes were significantly reduced in the diabetic resistance training group, compared to the diabetic controls (P‏<0.05); however, it provided no significant change in them, compared to the healthy control group (P‏>0.05).
Discussion
The present study results revealed that 10 weeks of moderate-intensity continuous training and high-intensity interval training decreased the serum levels in resistin and chemerin in training groups, compared to the diabetic control group. Besides, due to the above-mentioned points, liver enzymes were improved and the level of serum insulin and fasting blood glucose was decreased. These data may have resulted from various mechanisms, such as reducing the synthesis/diffusion of resistin and chemerin or the expression of its receptor in the liver. Understanding the relationship between resistin and chemerin and their relations with liver damage is critical for developing novel therapeutic and preventive solutions for an increased blood glucose level. The stimulation of resistin and chemerin and their receptors may provide a therapeutic approach for the prevention and improvement of diabetes conditions by different training methods.
Ethical Considerations
Compliance with ethical guidelines
This study was approved by the Research Ethics Committee of Arak University of Medical Sciences, Iran (Code: IR.Arakmu.rec.1394.329).
Funding
This study received no financial support from any organization.
Authors' contributions
All authors contributed in preparing this article.
Conflicts of interest
The authors declared no conflicts of interest.