Abstract
BACKGROUND: The trajectory of recovery following early rehabilitation after kidney transplantation remains poorly understood, particularly in relation to preoperative frailty. This study aimed to examine how physical function and health-related quality of life (HRQOL) recover over time after kidney transplantation with early rehabilitation. In particular, we assessed whether recovery patterns differed between robust and non-robust (pre-frail/frail) patients. METHODS: We retrospectively analyzed 15 living-donor kidney transplant recipients (median age: 45 years) who underwent transplantation between April 1, 2023, and June 18, 2025. All patients received early rehabilitation and functional assessments in the preoperative period and at one, two, and four months after transplantation. Frailty was assessed using the revised Japanese version of the Cardiovascular Health Study criteria, classifying patients into a robust group (n = 7) and a non-robust (pre-frailty and frailty) group (n = 8). The rehabilitation program included early mobilization, aerobic exercise, resistance exercise combined with virtual reality-based core training, and unsupervised home training. Measures included body composition, physical function (e.g., 6-minute walk distance (6MWD), gait speed, and muscle strength), HRQOL, and physical activity. Baseline characteristics were compared using t-tests or Fisher's exact test, and longitudinal as well as between-group differences were assessed using repeated-measures ANOVA with Bonferroni correction, with p < 0.05 considered statistically significant. RESULTS: In the overall cohort, there was a significant decrease in body weight postoperatively (p < 0.05), with significant improvements in 6MWD, gait speed, the Timed Up & Go test, knee extensor strength, the EuroQol 5-Dimension 5-Level index, the EuroQol visual analogue scale, and sedentary time observed by four months after transplantation (all p < 0.05). Both groups showed functional improvements. The robust group demonstrated earlier improvements and tended to show greater longitudinal gains in 6MWD over time (p = 0.054). Early rehabilitation had no adverse effects on graft function. CONCLUSIONS: Early rehabilitation after kidney transplantation improved physical function and HRQOL over four months, with benefits observed regardless of frailty status. Continued home training further supported recovery; however, the retrospective single-center design with a small sample size, short follow-up, variable adherence, and lack of a control group represent limitations.