INTRADIALYSIS EXERCISE AT THE BEGINNING VERSUS END OF THE DIALYSIS SESSION: EFFECT ON THE DIALYSIS DOSE

Abstract BACKGROUND AND AIMS There is controversy over whether intradialysis exercise has an effect on the dialysis dose. Moreover, theoretical models indicate that intradialytic exercise performed at the end of session may have a beneficial effect in postdialysis rebound. Perhaps this effect of exercise at the end of dialysis can improve the dialysis dose. The aim in this study is to determine the effect of intradialysis exercise on dialysis dose, as well as its effect on dialysis dose when performed during the first two or the last two hours of dialysis session. METHOD This study is a randomized clinical trial. Patients were randomized to exercise in the first (Start group) or last two hours (End group) of dialysis session. Intradialysis exercise consists of a video game adapted to dialysis: Treasure hunting. It is a non-immersive virtual-reality game in which the patient must catch some objectives avoiding obstacles by moving the lower limbs. The exercise session lasts from 20 to 40 min. Intensity was checked through the rate of perceived exertion. Dialysis dose was measured through Kt/V single pool (Kt/V sp), urea reduction percentage (URP), KT and dialisance Kt/V (Kt/Vds) in the short period between dialysis, midweek. These was determined in two different weeks, in one week patients were at rest and in the other week patients did intradialysis exercise. The lean tissue mass (LTM) was determined by multi-frequency stereoscopic bioimpedance. This study is funding from Programa Estatal de I + D + i Orientada a los Retos de la Sociedad, del Plan Estatal de Investigación Científica y Técnica y de Innovación 2017–2020 del Gobierno de España. RESULTS This is an open recruitment study, at the time of this communication 29 patients are active, 14 in Start group and 15 in End group. Age mean (SD) 74 (12) years, males 17, Charlson's Index 8.1 (2.24), time on hemodialysys treatment 55.72 (57.67) months, central venous catheter 8, HDFOL 8. A mixed analysis of repeated measures has been developed with each measure of dialysis dose as the dependent variable (Kt/Vsp, URP, KT and Kt/V ds) and independent variables: group (Start versus End), duration of exercise session and LTM. There were no differences in dialysis dose between Start and End groups. Duration of exercise session significantly increased the dialysis dose (Kt/Vsp + 0.015, P = 0.007, URP + 0.23 P = 0.01 and Kt/V ds + 0.015, P = 0.01). CONCLUSION The time of the dialysis session in which physical exercise is performed does not influence the dialysis dose. Longer duration of the intradialysis exercise session increases the dialysis dose.