Effects of Endurance Training on Lipid Metabolism and Glycosylated Hemoglobin Levels in Streptozotocin-induced Type 2 Diabetic Rats on a High-fat Diet

[Purpose] Exercise has been recognized as a simple and economical therapeutic modality that effectively benefits patients with diabetes, for instance, increasing insulin sensitivity in type 2 diabetes. However, thus far, no studies have examined the effect of endurance training exercises on type 2 diabetes. Therefore, this study examined the effect of endurance training exercise regimens on body weight, glucose and insulin levels, lipid profiles, and HbA1c levels in STZ-induced type 2 diabetic rats on a high-fat diet. HbA1c was considered an indicator of glucose control during endurance training. [Methods] A total of 36 rats were included in this study. Diabetes was induced by administering STZ to 2 groups of 12 rats each, and, the remaining 12 rats were classified as the normal group. Biochemical parameters were measured 28 days later, and included: serum total cholesterol, triglyceride, high-density lipoprotein, glycosylated hemoglobin, glucose, and insulin levels. [Results] A significant decrease in serum TC and TG levels, and an increase in HDL cholesterol level were observed in the endurance training group. Moreover, blood glucose and HbA1c levels after 28 days of exercising were significantly lower in the endurance training group than in the control group (p<0.05). [Conclusion] These results indicate that endurance training affects body weight and, lipid profiles, as well as fasting blood glucose, HbA1c, and insulin levels, in STZ-induced type 2 diabetic rats on a high- fat diet. We suggest that endurance training exercises may exhibit therapeutic, preventative, and protective effects against diabetes mellitus through improving lipid metabolism, glycemic control, and HbA1c levels.