Exercise as an Adjunctive Therapy for Patients on Maintenance Hemodiafiltration

The objectives of this study were twofold: first, to understand if hemodiafiltration (HDF) combined with exercise is a safe and effective treatment for patients with end-stage renal disease (ESRD/CKD 5D); and second, to explore the efficacy of exercise performed during dialysis sessions (intradialytic) versus between sessions (interdialytic). The study employed a retrospective observational design, analyzing data from CKD 5D patients undergoing maintenance HDF at the Fenix Nephrology group between 2021 and 2023. Inclusion criteria stipulated that participants were aged 18 years or older, on HDF with optimized medication, and agreed to participate in the exercise program with at least 80% adherence. Assessments were conducted at baseline and after six months of rehabilitation, including a step-test for endurance, handgrip strength measurement, one-repetition maximum (1RM) test for muscle strength, and the Kidney Disease Quality of Life Short Form (KDQOL-SF) questionnaire. Kt/V and urea reduction ratio (URR) were used as surrogates for HDF adequacy. The exercise protocol involved twice-weekly sessions, with aerobic exercises performed at 70% of the maximum heart rate achieved during the step test, and resistance exercises at 60% of 1RM. Participants self-selected their exercise timing, either intradialytic (during HDF sessions) or interdialytic (on non-dialysis days). For the intradialytic group, exercise was seamlessly integrated into the HDF session, excluding the initial and final two hours of dialysis.