Cognitive Impairment in Dialysis Patients: Focus on the Blood Vessels?

Abstract

Cognitive impairment is common in individuals with chronic kidney disease (CKD), particularly among those treated with dialysis.1–4 There are many potential causes, including metabolic abnormalities associated with kidney failure, although results from recent imaging studies in dialysis patients and epidemiologic studies in earlier stage CKD patients are more consistent with the hypothesis that vascular disease is the major contributing factor.4–12 Critically, cognitive impairment carries substantial risk, including depression and worse perceived quality of life,13–14 as well as a marked increase in mortality.15–17 Therefore, understanding the pathogenesis and exploring possible preventive treatments for cognitive impairment in CKD are critical to improving dialysis patient care. In this issue of AJKD, 2 studies evaluate cognitive function: the first, by Kurella Tamura and colleagues, reports the effects of frequent dialysis on cognitive function in individuals participating in the Frequent Hemodialysis Network (FHN) trials,18 while the second, by Yaffe and colleagues, examines the association between retinopathy and cognitive function in individuals with CKD stages 3–4 participating in the Chronic Renal Insufficiency Cohort (CRIC).19 This editorial focuses on the findings from the FHN trials, using the results from CRIC to provide important information on the potential impact of microvascular disease on cognitive function in people with CKD in order to place the results from Kurella Tamura et al into context.