Functional Status in Elderly Kidney Transplant Recipients: A Systematic Review Evaluating Physical Function, Frailty, and Cognitive Impairment as Predictors of Post-Transplant Outcomes.

BACKGROUND

The management of end-stage renal disease (ESRD) is undergoing a paradigm shift, with increasing emphasis on kidney transplantation as a preferred treatment modality for elderly patients (≥65 years), who constitute a substantial portion of new ESRD cases. Transplantation offers markedly superior survival and quality of life (QoL) advantages compared to dialysis for this demographic. Nevertheless, key determinants such as frailty, physical functionality, and cognitive function have emerged as critical predictors of post-transplant success. Despite their relevance, standardized methodologies for evaluating these parameters in transplantation candidacy remain absent. This systematic review examines the influence of frailty, physical functionality, and cognitive function on outcomes in elderly kidney transplant recipients.

METHODS

Adhering to PRISMA guidelines, a rigorous literature search was conducted across PubMed, CINAHL, Embase, PsycINFO, and the Web of Science for studies published up to October 31, 2024. Relevant studies focused on elderly transplant candidates and examined correlations between frailty, physical functionality, or cognitive function and post-transplant outcomes. The Newcastle-Ottawa Scale was employed to evaluate studies quality.

RESULTS

Seven studies met the inclusion criteria. Five explored physical functionality, demonstrating that better pre-transplant physical performance predicts enhanced survival. Two studies addressed frailty, utilizing the Fried frailty phenotype, and linked frailty to elevated mortality and diminished QoL recovery. Notably, no studies explored cognitive function in elderly kidney transplant candidates or recipients and its association with post-transplant outcomes, exposing a salient gap in the literature. The included studies' varied methodologies, reliance on single time-point assessments, and exclusive focus on kidney transplant recipients restrict both comparability among studies and the generalizability of findings to the broader end-stage renal disease (ESRD) population.

CONCLUSIONS

These findings underscore the profound impact of physical functionality and frailty on transplant outcomes in the growing elderly kidney transplant population, illuminating the necessity for standardized assessment protocols and targeted pre-transplant interventions. The critical gap in cognitive function research underscores a vital direction for future investigation. This research received no external funding. This review is registered with PROSPERO under registration ID CRD42025645838.