Exercise counters diet-induced obesity, proteinuria, and structural kidney alterations in rat

We studied the effects of exercise training in treating renal impairment due to hypertension and obesity in rats. Diet-induced obese and non-obese Wistar rats were assigned to four groups: Sed-Ob, Ex-Ob, Sed-C, and Ex-C (motor treadmill for 13 weeks; Ex=exercise-trained, C=control, Ob=obese, Sed=sedentary). Creatinine, proteinuria, and kidney structure were evaluated. Sed-C rats had normal and stable blood pressure (BP), while Sed-Ob rats developed hypertension. After 4 weeks of exercise, BP decreased in exercise-trained groups (less than 25% at the end of the experiment in obese rats, and less than 10% in non-obese rats). Both the body mass and retroperitoneal fat mass were lower in the exercise-trained groups than in the sedentary ones. Serum creatinine was not different among the groups, but the urinary protein excretion was significantly higher in the Sed-Ob group than in the matched non-obese group. Compared to the non-obese animals the mean glomerular volume increased by 45% in Sed-Ob rats and by 30% in Ex-Ob rats. Obese animals also showed increased mesangial volume density compared to non-obese animals. The present findings allow us to conclude that the exercise training could be an auxiliary practice to attenuate renal alterations seen in diet-induced obesity.