Mini Mental State Examination over time in chronic hemodialysis patients

Cognitive impairment is relatively common in end-stage renal disease patients on chronic hemodialysis, but the course of cognitive function deterioration in hemodialysis patients is essentially unknown. The present study aimed to evaluate if changes in Mini Mental State Examination (MMSE) over time in hemodialysis (HDP) and elderly (EP) patients differ significantly and determine the variables associated with such possible changes.

In 80 HDP and 160 EP, the MMSE was assessed at baseline and after 1 year. Patients were stratified at baseline and at 1 year into three groups according to the MMSE: normal cognitive function >23; mild-moderate cognitive dysfunction: 18-23; severe cognitive dysfunction: <18. Univariate and multivariate analyses were performed to determine the variables associated with MMSE change over time

One-year median reduction of MMSE was greater in HDP (from 24 to 21) than in EP (from 26 to 25) (P<.0001). A higher percentage of HDP than EP switched from normal to mild-moderate or severe MMSE group (P<.0001). At baseline, MMSE was negatively correlated with hypertension (P=.013), angina (P=.007) and Beck Depression Inventory (P=.041) and positively correlated with education (P=.017) and male gender (P=.015). No factors were found to be significantly associated with change of MMSE between baseline and month 12 in HDP.

One-year MMSE reduction was greater in HDP that in EP. No factors were associated with MMSE reduction in HDP. However, it remains likely that cardiovascular comorbidities and low haemoglobin levels are related to such decline.