Serum Irisin Changes Following Endurance Exercise and Caloric Restriction in Obese and Hypertriglyceridemic Rats

The present study aimed to confirm the hypothesis that indicates the role of Irisin as an adipomyokine, in boosting energy consumption and heat generation in brown fat tissue following moderate exercise and calorie restriction.
In this experimental study, 28 male Wistar rats (180-250g) were divided into four groups: Standard Control (STC), High Fat-high Carbohydrate diet (HFC), Stop High Fat- high Carbohydrate diet (S-HFC) and Exercise (EXE).The first 16 weeks were used to apply a special model (HF-HC diet for long-term) for inducing hypertriglyceridemia and weight gain, followed by five weeks of treatment for both groups (S-HFC and EXE). S-HFC group diet changed to standard food and the EXE group ran on treadmill for 20 minutes daily for 5 days a week. The other two groups continued the same diet as the first 16 weeks (standard diet for STC and HF-HC diet for HFC). Lipid profile was measured by spectrophotometry and Irisin by ELISA method.
The model we used to induce the hypertriglyceridemia (p=0.000) and obese (p=0.001) was significantly successful. Serum triglyceride levels decreased after the treatment (p=0.011) while there were no significant changes in other components of lipid profiles, weight and serum Irisin concentration. Moreover, the serum concentration of Irisin and triglyceride were not correlated (p=0.693, r=0.071).
The result of this study suggested that exercise along with calorie restriction significantly reduced serum triglyceride levels, but did not necessarily affect the weight loss. There was no correlation between the concentration of triglyceride and Irisin.