1. Investigación

Antecedentes. Un aumento de los biomarcadores de estrés oxidativo e inflamación se asocia con un deterioro de la función renal. El ejercicio físico puede mejorar el sistema de defensa antioxidante endógeno y el estado inflamatorio en pacientes en hemodiálisis. Se han realizado pocos estudios en esta población con programas que combinen ejercicio aeróbico y de fuerza a largo plazo, para estudiar su influencia en los biomarcadores de estrés oxidativo e inflamación. Este trabajo presenta los resultados obtenidos en un programa de ejercicio de cuatro meses de ejercicio aeróbico y de fuerza combinado en pacientes sometidos a hemodiálisis, bajo dos modalidades, intradiálisis y domiciliario. Métodos. Setenta y un pacientes en tratamiento de hemodiálisis se inscribieron y fueron asignados al azar en dos grupos, uno de ellos realizó un programa de ejercicio intradiálisis (grupo de intervención intradiálisis; n=36), y el otro llevó a cabo un programa de ejercicio en su domicilio (grupo de intervención en domicilio; n=35). Se determinaron los niveles séricos de biomarcadores de estrés oxidativo e inflamación antes y después de los programas de intervención. Resultados. Los niveles séricos de IL-6 mostraron una reducción significativa en el grupo de intervención intradiálisis después de un programa de ejercicio combinado de cuatro meses. No se observaron cambios significativos en el resto biomarcadores inflamatorios analizados. Tampoco se produjeron cambios significativos en los niveles de estrés oxidativo de los sujetos de estudio tras la realización del programa de ejercicio físico. Conclusiones. Un programa de ejercicio combinado de fuerza y resistencia aeróbica, de cuatro meses de duración, ha demostrado disminuir los niveles de IL-6 en pacientes en HD. Son necesarios nuevos estudios que analicen el efecto del ejercicio físico en esta población sobre la inflamación y el estrés oxidativo, con el fin de conocer la modalidad de ejercicio más beneficiosa para estos pacientes. / Background. An increase in oxidative stress and inflammation biomarkers is associated with a deterioration of renal function. Exercise can improve the endogenous antioxidant defence system and the inflammatory state in hemodialysis patients. Few studies have been conducted in this population with long-term programs that combine aerobic and strength exercises, to study their influence in oxidative stress and inflammation biomarkers. This work presents the results obtained in a four-month exercise program with combined aerobic and strength training in patients undergoing hemodialysis, under two modalities, intradialysis and homebased. Methods. Seventy-one patients undergoing hemodialysis were enrolled and randomized into two groups, one of them performing an intradialysis exercise program (intradialysis intervention group; n=36), and the other carrying out a home-based exercise program (home-based intervention group; n=35). Serum levels of oxidative stress and inflammation biomarkers were determined before and after the intervention programs. Results. Serum levels of IL-6 showed a significant reduction in the intradialysis intervention group after a four-month combined exercise program. No significant changes were observed in the rest of the inflammatory biomarkers analyzed. There were also no significant changes in the levels of oxidative stress in the study subjects after the physical exercise program. Conclusions. A four-month combined strength and aerobic endurance exercise program has been shown to decrease IL-6 levels in HD patients. New studies are needed to analyze the effect of physical exercise in this population on inflammation and oxidative stress, in order to know the most beneficial exercise modality for these patients.

It has been suggested that physical exercise in chronic hemodialysis could improve dialysis dose and reduce postdialysis rebound. A randomized controlled trial was performed to compare a group of patients doing physical exercise during the first 2 h of hemodialysis sessions and another group doing physical exercise at home. The descriptive variables, dialysis doses measured by KtV, and rebounds (urea, creatinine, potassium, phosphorus), were recorded. For 69 patients: the mean KtV was 1.84; the 30-min rebound of creatinine was 32.37%, urea 24.39%, potassium 15.31%, and phosphorus 51.29%. For each patient, the basal measurement was compared with those determined when performing physical exercise; no statistically significant differences were observed between the changes determined to dose and rebound in the group with hemodialysis exercise compared to those of the home exercise group. In conclusion, performing physical exercise during the first 2 hours of hemodialysis sessions neither lowered postdialysis molecules rebound nor improved dialysis dose.

Objective: The main objective of this investigation was to assess feasibility of conducting a future RCT with an intradialysis non-immersive virtual reality exercise intervention. The secondary aim was to explore the impact of either conventional or VR exercise on physical function. Design: Feasibility randomized trial Participants: 18 subjects who participated in a 16 weeks intradialysis combined exercise program. Interventions: The program lasted 4 additional weeks of either combined exercise or virtual reality exercise. Main outcome measures: Physical function was measured through several reliable tests (sit to stand to sit tests 10 and 60, gait speed, one-leg heel rise tests and 6-minute walk test) at baseline, after 16 weeks of intradialysis combined exercise and by the end of 4 additional weeks of exercise. Adherence to the exercise programs was registered. Results: There was a significant time effect, so that physical function improved in both groups. By the end of the 20 weeks, function improved as measured through the sit to stand to sit test 10 and 60, gait speed, one-leg heel rise left leg and the 6-minute walk test. Changes that did not occur due to error in the test were seen after 20 weeks were achieved in the sit to stand to sit test 60, gait speed, one-leg heel rise test for the left leg and 6-minute walking test. Conclusion: Virtual reality was a feasible intervention. Both interventions improved physical function. Adherence was not significantly different between groups.