The effect of an interval training course on nitric oxide levels, insulin resistance, and some blood lipid factors in type 2 diabetic male rats

Background: Diabetes is a metabolic and vascular disorder characterized by endothelial dysfunction. Physical activity, particularly intermittent exercise, may offer therapeutic benefits. This study examined the effects of six weeks of intermittent exercise on serum nitric oxide (NO), insulin resistance, and lipid profiles in male diabetic rats. Methods: Sixty Wistar rats (8 weeks old, 200 ± 20 g) were divided into six groups (n=10): healthy control, sham, interval training, interval training + saline, diabetic control, and diabetic + interval training. Diabetes was induced via nicotinamide-streptozotocin injection. The exercise groups underwent treadmill training (5 sessions/week for 6 weeks). Post-intervention, glucose, insulin, NO, LDL, HDL, triglycerides, and cholesterol were measured. Results: Diabetes induction significantly increased glucose and insulin resistance while reducing insulin and NO levels compared to controls (P < 0.001). After six weeks, the diabetic + exercise group showed significant reductions in glucose and insulin resistance (P < 0.001) and increased NO levels (P < 0.001) versus the diabetic group. Insulin levels did not differ significantly among the groups (P = 0.11). Lipid profiles (LDL, HDL, triglycerides, cholesterol) remained unchanged (P > 0.05). Conclusion: Six weeks of intermittent exercise improved glucose metabolism and vascular function in the diabetic rats by reducing insulin resistance and increasing NO levels, suggesting its potential as a non-pharmacological therapy for diabetes-related endothelial dysfunction.