Adverse cardiac responses to alpha-lipoic acid in a rat-diabetic model: possible mechanisms?
OBJECTIVE We aimed to examine the changes in serum insulin and leptin levels in induced type 1 diabetes mellitus in relationship to glycemic state and lipid profiles and to clarify the role of lipoic acid (LA). METHODS Ninety-six male rats were equally divided into the following: a control group (normal, nondiabetic), a diabetic group induced by subcutaneous injection of alloxan (non-LA-treated), and an LA-treated diabetic group (for 4 weeks). Body weight, serum lipid profile, glucose, insulin, homeostasis model assessment-insulin resistance (HOMA-IR), and leptin were measured. RESULTS This study showed a significant increase in serum triacylglycerol (TG), total cholesterol, glucose levels, and HOMA-IR and a significant decrease in body weight gain, insulin, and leptin levels in the diabetic group compared to the control group. LA treatment induced a significant decrease in glucose, TG, and total cholesterol levels and significantly increased serum insulin and leptin levels in comparison with the diabetic group. CONCLUSION Induced diabetes resulted in insulin resistance, hyperlipidemia, and hypoleptinemia, while LA ameliorates these changes and improves insulin sensitivity.