Acute intradialytic exercise and oxidative stress in hemodialysis patients

Intradialytic Exercise: Effects on Arterial Stiffness and Gait Speed in Patients Undergoing Hemodialysis

BACKGROUND The benefits of exercise for vascular and physical health in patients on chronic hemodialysis (CHD) are controversial. This study evaluated the outcomes of an intradialytic aerobic exercise program on carotid-femoral pulse wave velocity (cfPWV, an index of arterial stiffness), gait speed, and a sit-to-stand test in patients with CHD. MATERIAL AND METHODS A total of 114 CHD patients were randomly assigned to the exercise or the control (regular care) group. Patients performed intradialytic cycling exercises (3 sessions/week for 12 months) for 20 minutes in a supine position and the exercise protocol was set at a low-to-moderate intensity, defined as activities eliciting 3 to 5.9 metabolic equivalents. Data on cfPWV, gait speed, and the 5-times sit-to-stand test were collected. cfPWV was determined from the time taken for the arterial pulse to propagate from the carotid to the femoral artery and were compared between the 2 groups. RESULTS Arterial stiffness was improved, as evidenced by a significant decrease in cfPWV, in the exercise group compared to the control group (p<0.001). Generalized estimating equations analysis revealed a reduction in cfPWV at 6 and 12 months after the exercise intervention (p<0.001). Gait speed was significantly faster in the exercise group than in the control group (p=0.019). No exercise-related adverse events were reported. Results of 5-times sit-to-stand and body composition did not differ significantly between the 2 study groups. CONCLUSIONS Intradialytic cycling exercise significantly improved cfPWV and gait speed in CHD patients during the 12-month study period.

Proteomic profiling of protein expression changes after 3 months-exercise in ESRD patients on hemodialysis

The prevalence of chronic kidney disease (CKD) is steadily increasing, and it is a global health burden. Exercise has been suggested to improve physical activity and the quality of life in patients with CKD, eventually reducing mortality. This study investigated the change in physical performance after exercise in dialysis-dependent patients with CKD and analyzed differentially expressed proteins before and after the exercise. Plasma samples were collected at enrollment and after 3 months of exercise. Liquid chromatography with tandem mass spectrometry analysis and data-independent acquisition results were analyzed to determine the significantly regulated proteins. A total of 37 patients on dialysis were recruited, and 16 were randomized to exercise for 3 months. The hand grip strength and the walking speed significantly improved in the exercise group. Proteome analysis revealed 60 significantly expressed proteins after 3 months of exercise. In the protein functional analysis, the significantly expressed proteins were involved in the immune response. Also, some of the key significantly expressed proteins [(M Matrix metallopeptidase 9 (MMP-9), Activin A Receptor Type 1B (ACVR1B), Fetuin B (FETUB)] were validated via an enzyme-linked immunosorbent assay. Our results showed that exercise in dialysis-dependent patients with CKD could improve their physical performance. These results indicated that this beneficial effect of exercise in these populations could be associated with immune response.

Exercise training in dialysis patients: impact on cardiovascular and skeletal muscle health

Dialysis patients show a high rate of reduced functional capacity, morbidity and mortality. Cardiovascular disorders, muscle atrophy and malnutrition play an essential role among the aetiological factors. Sedentary lifestyle characterizes them and contributes to the aggravation of the disorders. On the contrary, exercise training is an important preventive and therapeutic tool both for cardiovascular problems and for the appearance of muscle atrophy in dialysis patients. Regular exercise causes both central (cardiac) and peripheral (muscular) adaptations, improving functional capacity. In particular, circulatory system clinical trials in haemodialysis (HD) patients documented that exercise has favourable effects on heart function, promotes balance on the cardiac autonomic nervous system and contributes to the management of arterial hypertension. In the muscular system, it prevents muscle atrophy or contributes significantly to its treatment. The main preventive mechanisms of the beneficial effect of exercise on the muscles constitute the inhibition of the apoptotic processes and protein degradation. Exercise training in HD patients leads to an increase of muscle fibers, mitochondria and capillaries, and the combination of regular exercise and dietary strategies is even more effective in preventing or treating muscle atrophy. Finally, an improvement in functional capacity and quality of life was found also in peritoneal dialysis patients following exercise training.

Effect of a Supervised Peridialytic Exercise Program on Serum Asymmetric Dimethylarginine in Maintenance Hemodialysis Patients

End-stage renal disease (ESRD) patients treated with maintenance haemodialysis (MHD) have alarmingly high atherosclerotic cardiovascular disease morbidity and mortality. Nitric oxide (NO) is the principal endogenous antiatherosclerotic molecule. Increased asymmetric dimethylarginine (ADMA), an endogenous NO synthase inhibitor, was strongly implicated in endothelial dysfunction, premature atherosclerosis, vascular events, and mortality. Regular physical exercise effectively decreased serum ADMA in several patient cohorts, but this potential benefit has not been specifically explored among MHD patients. Forty-four middle-aged ESRD patients treated with thrice-weekly MHD for ≥6 months completed a 6-months regimen of peridialytic lower limb exercise comprising predialytic 10-12 stretching cycles and 20-30 minutes of intradialytic pedaling cycles. Before and after the study, predialytic haemoglobin, serum ADMA, urea, creatinine, calcium, phosphorus, and C-reactive protein (CRP) were measured. Dialysis adequacy was assessed by single-pool Kt/V. The average total physical activity (PA) level was assessed by the International Physical Activity Questionnaire (IPAQ). P values <0.05 denoted a statistical significance. The overall level of PA, on both categorical and continuous scales, has significantly increased after application of the exercise program. However, S. ADMA increased from a median of 2375 to 3000 ng/mL (P=0.016). Thirty-one patients sustained an increase in S. ADMA (ADMA_Inc), whereas 13 patients had a declining or stable S. ADMA (ADMA_Dec). Compared with ADMA_Inc, ADMA_Dec patients had significantly higher Kt/V (P=0.02), higher grade of the basal general PA level (P=0.017), and significantly fewer intradialytic hypotension episodes (IDHs) (P=0.019). The increase in the S. ADMA and the poststudy S. ADMA level had statistically significant positive correlations with the number of IDHs (r = 0.401, P=0.007 and r = 0.305, P=0.044, respectively). A 6-month program of combined aerobic and resistance peridialytic exercise failed to reduce S. ADMA in most MHD patients studied. A modest S. ADMA decline, however, occurred in patients with higher basal PA levels, higher Kt/V, and less IDHs. A potential exercise benefit may be promoted by a multidisciplinary approach targeting increased PA, improved dialysis efficiency, and prevention of IDHs.

Beneficios del ejercicio físico en la sesión de hemodiálisis. Una revisión sistemática

Objetivo: El objetivo principal de esta revisión fue conocer los principales beneficios del ejercicio físico durante la sesión de diálisis, en los pacientes en programa de hemodiálisis periódicas.Material y Método: Se llevó a cabo una revisión sistemática a través de las bases de datos Pubmed, Science Direct y Google Académico. Se incluyeron artículos científicos en inglés y español, y se analizaron los artículos que trataban sobre ejercicio físico en la sesión de hemodiálisis. Se excluyeron aquellos artículos que no presentaran resultados y en los que el ejercicio físico fuese domiciliario.Resultados: Se incluyeron 18 artículos publicados entre 2015 y 2019. Todos los artículos fueron de diseño experimental. Se encontró una mejoría significativa de la fuerza muscular, al igual que de la capacidad física y de de la sintomatología depresiva. En menor medida, se observó una disminución de la presión arterial, disminución del proceso inflamatorio, mejoría de los valores nutricionales y mejora de la calidad de vida de estos pacientes.Conclusiones: El ejercicio físico en la sesión de hemodiálisis tiene beneficios para la salud de los pacientes. El ejercicio físico de baja intensidad, así como la electroestimulación neuromuscular en las sesiones de diálisis, mejora objetivamente la fuerza muscular, aumenta la capacidad física, mejora la sintomatología depresiva con un mejor manejo del estrés y la ansiedad. Además, perece que puede mejorar el proceso inflamatorio, parámetros nutricionales y disminuir la presión arterial, así como mejorar la calidad de vida. La electroestimulación neuromuscular y el ejercicio físico de baja intensidad, son los ejercicios más utilizados.

Could physical exercise help modulate the gut microbiota in chronic kidney disease?

Chronic kidney disease (CKD) patients have several metabolic disorders caused by chronic oxidative stress and inflammation. The imbalance of gut microbiota has been identified as a factor that may contribute to the development of these disorders, which can promote cardiovascular disease in CKD patients. Among several strategies to modulate gut microbiota, physical exercise could represent a new nonpharmacological approach. Although exercise can reduce cardiovascular risk in CKD patients through its beneficial effects on oxidative stress and inflammation, there are no available data regarding the relationship between exercise and modulation of gut microbiota in CKD patients. This review is intended to provide a brief overview of the hypothesis regarding gut microbiota modulation through physical exercise, with a particular emphasis on CKD.