Factors that contribute to the cognitive impairment in elderly dialysis patients

To evaluate the cognitive function in dialysis patients over 60 years old and identify the contributing factors.

A group of elderly dialysis patients in the Department of Nephrology, Pan'an People's Hospital between March 2015 and June 2018 were chosen as the subjects for this study. Patients were divided into two groups, those with cognitive impairment and those with normal cognitive function. Results of their Montreal Cognitive Assessment (MoCA) scores, Controlled Oral Word Association Test (COWAT), Wechsler Adult Intelligence Scale Digit Span subtest (WDMS), and Stanford Diagnostic Math Test (SDMT) were reviewed and analyzed.

Among the 110 elderly dialysis patients, 75 patients (68.18%) showed different levels of damage to their cognitive function. Their assessment scores on MoCA (total), MoCA subtests: visuospatial/executive, naming, attention, language, delayed recall, abstraction and orientation, COWAT (total), COWAT1, COWAT2, COWAT3, WMDS-Backward, and SDMT are significantly lower than patients with normal cognitive abilities (p < 0.05). Further analysis showed that the highest percentage (72.00%) of patients had impairment with visuospatial/executive function; and, of the 75 cognitive impaired patients, 37.33% showed cognitive damage in two MoCA subtests simultaneously. Patients with and without cognitive impairment showed a significant (p < 0.05) difference on factors including age, education level, employment status, financial situation, dialysis vintage, serum albumin, and hemoglobin.

Elderly patients on dialysis have a higher risk of becoming cognitive impaired. The cognitive impairment in elderly dialysis patients was significantly associated with age, dialysis vintage, and levels of serum albumin and hemoglobin.