Fatigue and Cognitive Impairment in Patients with Kidney Failure Not Requiring Kidney Replacement Therapy and...

Background: Cognitive impairment and fatigue are common in patients with advanced chronic kidney disease (CKD). However, whether these symptoms reflect kidney failure itself or factors associated with hemodialysis (HD) remains unclear. This study compared cognitive performance and fatigue between patients with CKD G5 not requiring kidney replacement therapy, referred to as CKD G5 not on dialysis (CKD G5 ND), and those receiving maintenance HD. Methods: In this cross-sectional, single-center study, 68 clinically stable patients with kidney failure were enrolled, including 27 patients with CKD G5 ND and 41 patients receiving HD. Cognitive performance was assessed using the Montreal Cognitive Assessment (MoCA) and fatigue via the Fatigue Assessment Scale (FAS). Results: Global cognitive performance did not differ significantly between patients receiving HD and those with CKD G5 ND, with median MoCA scores of 24.00 and 23.00, respectively. Cognitive impairment was frequent, affecting 61.0% of HD patients and 74.1% of those with CKD G5 ND. Fatigue severity was also comparably high, with significant fatigue in 51.2% and 44.4% of individuals, respectively. No association was observed between global cognitive performance and fatigue. Exploratory analyses showed that language performance was inversely associated with total and mental fatigue after false discovery rate correction. In the adjusted logistic regression, HD status was associated with lower odds of cognitive impairment; however, this finding should be interpreted cautiously, given the cross-sectional design, small sample size, and baseline clinical differences between groups. Conclusions: Cognitive impairment and fatigue were highly prevalent both in patients with CKD G5 ND and those receiving maintenance HD, with no significant between-group differences in global cognitive performance or fatigue severity scores. These findings suggest that neuropsychological vulnerability may be present in patients with kidney failure before dialysis initiation.