Cognitive impairment in patients with moderate to severe CKD: The Salford Kidney Cohort Study

Background Cognitive Impairment (CI) in chronic kidney disease (CKD) is common and underrecognized [1,2]. Determining risk factors for CI and whether speed of CKD progression is an important consideration may help identification of CI by nephrologists. Vascular disease is thought to underpin CI in CKD and by segregating CKD patients with proven vascular disease, we may also be able to discover other important associations with CI in CKD patients. Method 250 patients in a UK prospective cohort of CKD patients underwent 2 cognitive assessments; Montreal Cognitive Assessments and Trail Making Tests. CI was defined using validated population cut offs (CI) and relative cognitive impairment (rCI). rCI was defined by < 1SD below mean Z score on any completed test. Two multivariable logistical regression models identified variables associated with CI and rCI. Results 44% and 24.8% of patients suffered CI and rCI respectively. Depression, previous stroke and older age were significantly associated with CI. Older age was significantly associated with rCI (p=<0.05), higher proteinuria and use of psychodynamic medications were also significantly associated with rCI (p=0.05). Delta eGFR in patients with CI and rCI compared with those having normal cognition was similar (-0.77 versus -1.35 mL/min/1.73m2/yr p=0.34 for CI and -1.12 versus -1.02 mL/min/1.73m2/yr p=0.89 for rCI). Conclusion Risk factors for CI in CKD include; previous stroke, depression or anxiety, higher proteinuria and prescription of psychodynamic medications. Patients with a faster eGFR decline do not represent a group of patients at increased risk of CI.