Cognitive Impairment Across the Spectrum of Chronic Kidney Disease: Clinical Characteristics and Implications for Practice-Is There a Role for Medical Nutritional Therapy?

Cognitive impairment is increasingly recognized as a frequent and clinically significant complication of chronic kidney disease (CKD). Across the CKD spectrum, patients commonly exhibit a cognitive profile dominated by executive dysfunction and slowed processing speed, reflecting cumulative vascular, metabolic, and systemic burden. Cognitive impairment is not merely an epiphenomenon of aging but a modifier of clinical trajectory, with implications for treatment adherence, decision-making capacity, dialysis planning, transplantation, and mortality risk. This narrative review synthesizes current evidence regarding epidemiology, domain-specific cognitive patterns, risk modifiers, nutritional determinants, and clinical consequences across predialysis and dialysis populations. We discuss executive-attentional dysfunction and the interaction among kidney dysfunction, vascular burden, depressive symptoms, nutritional status, and cognitive vulnerability. Particular emphasis is placed on pragmatic cognitive assessment and potentially modifiable contributors, including anemia, nutritional deficiencies, dietary patterns, medication-related effects, and dialysis-related hemodynamic instability. Brief screening approaches combining global and executive-function tools may facilitate early identification of clinically meaningful impairment. Integrating cognitive and nutritional assessment into routine CKD care may improve risk stratification, individualized management, and clinical decision-making while identifying potential targets for prevention and intervention.