Kidney disease has been linked with the development of cognitive problems, according to research.

Chronic kidney disease, also called chronic kidney failure, involves a gradual loss of kidney function. It has been associated with cognitive dysfunction in epidemiological studies, but it is unclear if this association is independent of blood pressure (BP) and related to cerebral small vessel disease (CSVD). 

The new study by the American Society of Nephrology relied on data from a population-based study of 2,738 participants without dementia, of which 187 (7 per cent) had chronic kidney disease and 251 (9 per cent) had albuminuria -- a urinary marker of kidney disease. 

In the study, the team evaluated baseline kidney function in relation to subsequent BP measurements and CSVD, and to mild cognitive impairment (MCI) and dementia.

The findings, presented at the ASN Kidney Week, showed that albuminuria was associated with both CSVD markers and cognitive disorders independent of premorbid BP, indicating that 1) hypertensive cerebrovascular injury (reflected on CSVD markers) may not be reflected by BP measurements alone, or 2) other shared pathobiology may exist between the kidney and the brain, for instance with mechanisms such as endothelial dysfunction.

Albuminuria was associated with signs of silent stroke, and patients with albuminuria had a 65 per cent higher risk of developing mild cognitive impairment or dementia. 

Chronic kidney disease was not associated with markers of silent cerebrovascular disease but was associated with a 51 per cent higher risk of developing dementia.

"Our results highlight the importance of albuminuria as a cerebrovascular and cognitive risk factor and indicate that there may be additional shared disease mechanisms in the kidney and the brain beyond hypertension," said corresponding author Dearbhla Kelly, from St. James's Hospital, Dublin, Ireland.