Cognitive Decline, Depression and Quality of Life in Patients at Different Stages of Chronic Kidney Disease

Introduction: Patients with chronic kidney disease constitute a population at high risk for cognitive decline. Therefore they are often users of "polypharmacy" and present comorbidities such as diabetes and hypertension.

Objective: To evaluate cognitive function, depression and quality of life in patients at different stages of chronic kidney disease.

Method: Cross-sectional study carried out from June to December 2007 in 119 patients: 27 in peritoneal dialysis, 30 in hemodialysis, 32 in pre-dialysis and 30 with arterial hypertension. Several tests were performed: Mini-Mental State Examination (MMSE), Verbal Fluency Test, Digits, Clock Test, Codes, SF-36 (Quality of Life) and the Beck Depression Inventory. Additionally, clinical and laboratory data of the patients were collected and medication use was recorded.

Results: There was no difference in mean age of the patients among the groups. There was no statistical difference when cognitive impairment was assessed by the Mini-mental test (p = 0.558). The Digit Span test (p = 0.01) and Clock test (p = 0.02) were significantly worse in the hemodialysis patients, and there was a trend with Code test (p = 0.09) in these patients. There was no difference between groups in the level of depression and Quality of Life.

Conclusion: These results show that cognitive impairment is frequent among patients in with CKD, particularly in those undergoing hemodialysis and suggest the need to conduct longitudinal studies to confirm whether or not there is an influence of dialysis treatment on the cognitive decline.