Cognitive and renal dysfunction in the elderly

Cognitive impairment has been associated with several diseases and organic disturbances but few studies have explored the relationship between renal function and cognition.

The aim of this study was to compare the renal function of elderly patients with and without Alzheimer's disease, and to identify potential associated comorbidities, as well as the presence of microalbuminuria.

A group of 60 patients with dementia syndrome and probable Alzheimer's disease, and 20 patients without dementias, followed at the Geriatric outpatient unit of the Santa Casa de São Paulo Hospital, were selected for this study.

The results showed that the groups studied differed in terms of age, gender and Mini-Mental State Exam score, but no statistical difference was found for the presence of comorbidities (diabetes mellitus, dyslipidemia and systemic arterial hypertension). A significant difference in estimated creatinine clearance was observed between the two groups, with the Alzheimer's disease patients presenting significantly lower values than control subjects. Similarly, analysis of a portion of the two groups for the presence of microalbuminuria revealed a statistically significant difference between the two groups.

The study conclusions were that patients with Alzheimer's disease had lower glomerular filtration and a higher incidence of microalbuminuria, yet without having more classic risk factors for Alzheimer's disease such as systemic arterial hypertension, diabetes mellitus or dyslipidemia.