Frailty and sarcopenia in PeriDialysis-chronic kidney disease: a narrative review of prevalence, prognostic implications, and therapeutic opportunities

Background The transition from advanced chronic kidney disease (CKD) to maintenance dialysis is a period of substantial physiological and functional vulnerability. This Review, the peri-dialysis period is defined as the interval from CKD G5 (estimated glomerular filtration rate <15 mL/min/1.73 m 2 ) to 3 months after dialysis initiation. Frailty and sarcopenia are common during this transition and may substantially influence treatment tolerance, independence and clinical outcomes. Methods We narratively synthesize evidence on the prevalence, clinical significance, assessment challenges, prognostic implications, and therapeutic opportunities related to frailty and sarcopenia among PeriDialysis CKD patients. Results Frailty and sarcopenia are overlapping but distinct syndromes. Their development in kidney failure is driven by inflammation, protein-energy wasting, metabolic acidosis, insulin resistance, hormonal disturbances, multimorbidity, inactivity and dialysis-related stressors. Both conditions are associated with higher risks of mortality, hospitalization, functional decline, disability and poorer health-related quality of life. However, substantial heterogeneity exists across diagnostic definitions, assessment tools and measurement timing. Fluid overload and rapid shifts in body water complicate interpretation of body-composition measures, while handgrip strength, gait speed, chair-stand tests and clinician-rated frailty scales offer feasible approaches for routine assessment. Evidence across studies suggests that functional measures are consistently prognostic and may provide complementary or greater prognostic information than muscle mass alone; however, direct head-to-head comparisons are limited and results depend on case definitions and measurement timing. Conclusions Frailty and sarcopenia should be assessed repeatedly before and after dialysis initiation rather than considered fixed characteristics. A transition-focused, multidisciplinary approach integrating exercise and rehabilitation, individualized nutritional care, symptom and comorbidity management, dialysis optimization and social support may help preserve function and independence.