The effect of eight weeks of high-intensity interval training on changes in the levels of leptin, adiponectin and insulin levels in male Wistar rats

Obesity leads to impaired secretion and expression of adipokines in humans and causes the onset of type 2 diabetes. Although the role of regular exercise in the prevention of metabolic diseases has been reported, the mechanism of high-intensity exercise is still not well understood. Therefore, the aim of the present study was to investigate the effects of 8 weeks of high-intensity interval training on the changes in insulin, leptin and adiponectin levels in male Wistar rats with type 2 diabetes.

In this experimental study 20 male Wistar rats aged 8-10 weeks were randomly divided into four groups: Control, type 2 diabetes, exercise, and diabetes-exercise. Type 2 diabetes was induced by a high-fat diet and a single dose of streptozotocin (STZ). The rats in the exercise and diabetes-exercise groups completed 8 weeks of HIIT training (running at an intensity of 85-95% of maximum speed, intervals of 4-10). Insulin, adiponectin and leptin levels were measured in serum. Homeostasis Model Assessment for Insulin Resistance (HOMA-IR), the Homeostasis Model Assessment for Insulin Resistance-beta (HOMA-β) and the Quantitative Assessment of Insulin Sensitivity Index (QUICKI) were calculated to assess insulin resistance and sensitivity.

Diabetes decreased the level of insulin, adiponectin and leptin in serum. HIIT reversed the impairments caused by diabetes. HOMA-IR, HOMA-β and QUICKI also improved in the diabetes-exercise groups.

Overall, our results confirmed that diabetes has detrimental effects on serum leptin, adiponectin and insulin indices and that HIIT training can improve these disorders.