Comparison of continuous training with and without caloric restriction on leptin and adiponectin gene expression in adipose tissue and insulin resistance in elderly rats

Adipose tissue plays a crucial role in body metabolism and inflammation by releasing adipokines. Both caloric restriction and continuous exercise can impact adipose tissue and affect inflammation and the aging process. Therefore, the aim of this research was to investigate the effect of caloric restriction and continuous exercise on the expression of the leptin gene, adiponectin, the ratio of adiponectin to leptin, and insulin resistance in aged rats. The study included a total of 36 aged male Wistar rats (26 months old), randomly divided into four groups: control, restriction, caloric, and continuous exercise, as well as caloric restriction+continuous exercise. The rats underwent a six-week continuous training protocol, with five sessions per week. Samples were then taken from the epididymal fat tissue of the rats, and Real-Time PCR was used to measure the expression of the adiponectin and leptin genes. Statistical analysis was conducted using non-parametric statistics. The statistical tests showed that the expression of the adiponectin gene significantly increased in the caloric restriction and continuous exercise groups. However, in the caloric restriction+continuous exercise group, the expression of the adiponectin gene decreased. Furthermore, there was no significant difference in leptin gene expression, the ratio of adiponectin to leptin gene expression, or insulin resistance in fat tissue among the groups. These findings suggest that while caloric restriction and continuous exercise have beneficial effects on increasing adiponectin gene expression, their combination may not always result in synergy.