Effects of Three Different Frequencies of Aerobic Physical Activity on Heart and Kidney Tissues in Type 2 Diabetes-Induced Rats

OBJECTIVE: Exercise has many beneficial effects in the treatment and prevention of Type 2 Diabetes Mellitus (T2DM). The aim of this study was to evaluate the effect of physical activities with different frequencies performed within a total total duration of one week on the heart and kidney tissues and vascular endothelial growth factor (VEGF) expressions in experimental T2DM model. METHOD: Rats (n: 30) were divided into sedentary control (SC), sedentary T2DM (SD), T2DM and continuous exercise (DEc, 30 min/day, 5 days/week), T2DM and short bouts exercise (DEsb, 3x10 min/day, 5 days/week), T2DM and weekend warrior exercise (DEww, 35+40 min/day, 2 days/week) groups. Rats were administered streptozotocin (65 mg/kg) and nicotinamide (110 mg/kg) through intraperitoneal route. After 6-weeks of swimming exercise (total duration 150 min/week), biochemical analyzes were performed to measure oral glucose tolerance test, insulin sensitivity and cytokines. Histopathological and immunohistochemical analyses [VEGF, capillary density, Transforming growth factor beta (TGF-β)] were performed in heart and kidney tissues. RESULTS: Compared with sedentary T2DM rats, significant improvements were observed in all exercise groups in terms of blood glucose level, insulin sensitivity, capillary density in heart tissue, VEGF expressions in tissues, TGF-β expressions in kidney tissue and all histopathological analysis (p<0.05). CONCLUSION: This study shows that physical activity at various frequencies may significantly ameliorate harmful effects of T2DM on heart and kidney tissue without significant differences between exercise frequencies, provided that the total duration of aerobic exercise remains the same (150 min/week).