Efeito do exercício físico intradialítico com realidade virtual na força muscular de membros inferiores em pacientes com doença renal crônica: um ensaio clínico randomizado

Abstract

Introduction: Chronic kidney disease (CKD) frequently leads to muscle weakness, functional decline, and reduced quality of life (QoL). Intradialytic exercise has emerged as an effective strategy to mitigate these effects, and the use of virtual reality (VR) represents an innovative approach to enhance its benefits. Objectives: The primary objective was to compare the effects of intradialytic VR exercise performed during the first two versus the last two hours of hemodialysis on lower-limb muscle strength. Secondary objectives were to evaluate its impact on QoL, physical activity, cognitive function, and physical performance. Methods: This randomized clinical trial was conducted between 2021 and 2024 with Brazilian and Spanish patients. Participants were randomized to perform exercise during either the first (Group 1–2) or the last two hours of hemodialysis (Group 3–4). The intervention consisted of a 12-week non-immersive VR lowerlimb strengthening and endurance program (“Treasure Hunt”), performed two to three times per week, with progression guided by the Borg Scale (6–20). The primary outcome was lower-limb muscle strength, assessed using dynamometry of hip abductors, hip flexors, and ankle plantar flexors. Secondary outcomes included QoL (SF-36), physical activity level (Human Activity Profile), cognitive function (Mini-Mental State Examination), and physical performance (handgrip strength, 4-meter gait speed, and 10-repetition sit-to-stand test). Results: A total of 57 patients participated, with no significant differences between groups regarding age (67.8 ± 14.8 vs. 68.2 ± 12.0 years) or clinical characteristics. Brazilian participants (n=23 vs. n=34) were younger (60.3±13.2 vs. 73.4±10.9; p<0.001), had longer dialysis vintage (104.7±87.0 vs. 49.2±55.5; p<0.001), and lower Kt/V (1.6±0.2 vs. 1.8±0.3; p=0.002). Muscle strength increased in both groups, with greater gains in right hip flexors (Δ=16.7 N in Group 3–4 vs. Δ=8.1 N in Group 1–2; p<0.001) and right hip abductors (Δ=19.9 N vs. Δ=7.8 N; p<0.001). Ankle plantar flexion showed no significant improvement. Regarding QoL, the vitality domain of SF-36 improved significantly over time (Δ=15.0 in Group 1–2 and Δ=1.0 in Group 3–4; p=0.025), with no differences between groups. No significant changes were observed in physical activity or cognitive function. A significant group-by-time interaction was found for gait speed, with improvement in Group 3–4 (0.14 m/s vs. –0.05 m/s; p=0.007). In the STS-10 test, both groups improved (–1.0 s vs. –4.8 s; p=0.02), with significance only for Group 3–4 (p<0.001). Handgrip strength increased significantly on the right (0.7–1.9 kgf; p=0.031) and left (1.4–2.2 kgf; p=0.009) sides. Conclusion: Non-immersive VR exercise can be safely performed at any point during the hemodialysis session, improving muscle strength and function without significant effects on QoL, physical activity, or cognition.