Exercise Attenuates Renal Dysfunction with Preservation of Myocardial Function in Chronic Kidney Disease

Previous studies have suggested that exercise improves renal and cardiac functions in patients with chronic kidney disease. the aim of this study was to evaluate the effects of long-term aerobic swimming exercise with overload on renal and cardiac function in rats with 5/6 nefrectomy (5/6Nx). Eight Wistar rats were placed into 4 groups: Control (C), Control+Exercise (E), Sedentary 5/6Nx (NxS) and 5/6Nx+Exercise (NxE). the rats were subjected to swimming exercise sessions with overload for 30 min five days per week for five weeks. Exercise reduced the effect of 5/6Nx on creatinine clearance compared to the NxS group. in addition, exercise minimized the increase in mean proteinuria compared to the NxS group (96.9 +/- 10.0 vs. 51.4 +/- 9.9 mg/24 h; p<0.05). Blood pressure was higher in the NxS and NxE groups compared to the C and E groups (216 +/- 4 and 178 +/- 3 vs. 123 +/- 2 and 124 +/- 2 mm Hg, p<0.05). in the 200 glomeruli that were evaluated, the NxS group had a higher sclerosis index than did the NxE group (16% vs. 2%, p<0.05). Echocardiography demonstrated a higher anterior wall of the left ventricle (LV) in diastole in the NxS group compared with the C, E and NxE groups. the NxS group also had a higher LV posterior wall in diastole and systole compared with the E group. the developed isometric tension in Lmax of the heart papillary muscle was lower in the NxS group compared with the C, E and NxE groups. These results suggested that exercise in 5/6Nx animals might reduce the progression of renal disease and lessen the cardiovascular impact of a reduction in renal mass.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundacao Oswaldo Ramos (FOR)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, UNIFESP EPM, Dept Med, Div Nephrol, São Paulo, BrazilUniversidade Federal de São Paulo, Cardiophysiol & Pathophysiol Lab, São Paulo, BrazilUniv São Paulo, Sch Med, Heart Inst InCor, Lab Genet & Mol Cardiol, São Paulo, BrazilUniversidade Federal de São Paulo, UNIFESP EPM, Dept Med, Div Nephrol, São Paulo, BrazilUniversidade Federal de São Paulo, Cardiophysiol & Pathophysiol Lab, São Paulo, BrazilWeb of Scienc

Previous Exercise Training Has a Beneficial Effect on Renal and Cardiovascular Function in a Model of Diabetes

Exercise training (ET) is an important intervention for chronic diseases such as diabetes mellitus (DM). However, it is not known whether previous exercise training intervention alters the physiological and medical complications of these diseases. We investigated the effects of previous ET on the progression of renal disease and cardiovascular autonomic control in rats with streptozotocin (STZ)-induced DM. Male Wistar rats were divided into five groups. All groups were followed for 15 weeks. Trained control and trained diabetic rats underwent 10 weeks of exercise training, whereas previously trained diabetic rats underwent 14 weeks of exercise training. Renal function, proteinuria, renal sympathetic nerve activity (RSNA) and the echocardiographic parameters autonomic modulation and baroreflex sensitivity (BRS) were evaluated. In the previously trained group, the urinary albumin/creatinine ratio was reduced compared with the sedentary diabetic and trained diabetic groups (p &lt; 0.05). Additionally, RSNA was normalized in the trained diabetic and previously trained diabetic animals (p &lt; 0.05). The ejection fraction was increased in the previously trained diabetic animals compared with the diabetic and trained diabetic groups (p &lt; 0.05), and the myocardial performance index was improved in the previously trained diabetic group compared with the diabetic and trained diabetic groups (p &lt; 0.05). In addition, the previously trained rats had improved heart rate variability and BRS in the tachycardic response and bradycardic response in relation to the diabetic group (p &lt; 0.05). This study demonstrates that previous ET improves the functional damage that affects DM. Additionally, our findings suggest that the development of renal and cardiac dysfunction can be minimized by 4 weeks of ET before the induction of DM by STZ.Fundacao de Amparo a Pesquisa do Estado de Sao PauloFundacao de Amparo a Pesquisa do Estado de Sao PauloConselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Fundacao Oswaldo RamosFundacao Oswaldo RamosCNPq-Bolsa de Produtividade em pesquisa (BPQ)CNPqBolsa de Produtividade em pesquisa (BPQ

Previous exercise training has a beneficial effect on renal and cardiovascular function in a model of diabetes.

Exercise training (ET) is an important intervention for chronic diseases such as diabetes mellitus (DM). However, it is not known whether previous exercise training intervention alters the physiological and medical complications of these diseases. We investigated the effects of previous ET on the progression of renal disease and cardiovascular autonomic control in rats with streptozotocin (STZ)-induced DM. Male Wistar rats were divided into five groups. All groups were followed for 15 weeks. Trained control and trained diabetic rats underwent 10 weeks of exercise training, whereas previously trained diabetic rats underwent 14 weeks of exercise training. Renal function, proteinuria, renal sympathetic nerve activity (RSNA) and the echocardiographic parameters autonomic modulation and baroreflex sensitivity (BRS) were evaluated. In the previously trained group, the urinary albumin/creatinine ratio was reduced compared with the sedentary diabetic and trained diabetic groups (p<0.05). Additionally, RSNA was normalized in the trained diabetic and previously trained diabetic animals (p<0.05). The ejection fraction was increased in the previously trained diabetic animals compared with the diabetic and trained diabetic groups (p<0.05), and the myocardial performance index was improved in the previously trained diabetic group compared with the diabetic and trained diabetic groups (p<0.05). In addition, the previously trained rats had improved heart rate variability and BRS in the tachycardic response and bradycardic response in relation to the diabetic group (p<0.05). This study demonstrates that previous ET improves the functional damage that affects DM. Additionally, our findings suggest that the development of renal and cardiac dysfunction can be minimized by 4 weeks of ET before the induction of DM by STZ

Renal Function.

<p>Sedentary control (C), exercise control (E), sedentary 5/6Nx (NxS), exercise 5/6Nx (NxE). <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0055363#pone-0055363-g001" target="_blank"><b>Figure 1</b></a><b>A</b> - serum creatinine (Scr) expressed in mg/dL, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0055363#pone-0055363-g001" target="_blank"><b>Figure 1</b></a><b>B</b> - creatinine clearance (CrCl) expressed in ml/min, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0055363#pone-0055363-g001" target="_blank"><b>Figure 1</b></a><b>C</b> - proteinuria (Uprot) expressed in mg/24 h and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0055363#pone-0055363-g001" target="_blank"><b>Figure 1</b></a><b>D</b> – glomerular sclerosis index (GSI) expressed in %. <b>^&</b> p<0.05 vs. all groups.</p

Echocardiographic parameters in control – C, sedentary diabetic – D, trained control – TC, trained diabetic – TD and previously trained diabetic – PTD.

<p>Left ventricular mass (LV mass), left ventricular ejection fraction (LVEF%), left ventricular fractional shortening (LVFS%), circumferential fiber shortening (VCF), isovolumic relaxation time (IVRT) and myocardial performance index (MPI). * p<0.05 vs. C, # p<0.05 vs. D, + p<0.05 vs. TC, $ p<0.05 vs. TD.</p

Initial and final serum creatinine, creatinine clearance, proteinuria, fractional excretion of sodium (FE_Na+) and fraction excretion of potassium (FE_K+) in control – C, sedentary diabetic – D, trained control – TC, trained diabetic – TD and previously trained diabetic – PTD.

<p>The results are expressed as the mean ± SEM. ANOVA one way, * p<0.05 vs. C, # p<0.05 vs. D, + p<0.05 vs. TC, ≠ p<0.05 vs. all groups, @p<0.05 vs. initial data.</p

Experimental design, time course of exercise training protocol.

<p>0– Initial week of the protocols for all groups and initiation of exercise training in the PTD group; 4– Final week of exercise training in the PTD group (4 weeks); 4 to 5– Induction of DM in the PTD, TD and D groups. During this period, the PTD group was submitted to “maintenance exercise” (≈40% maximal running test) to avoid detraining; 5– Continuation of exercise training in the PTD group and initiation of exercise training in the TD and TC groups; 15– End of the protocol and initiation of the surgical procedures.</p