According to a study led by Temple University, decreased kidney function is associated with decreased cognitive functioning in areas such as global cognitive ability, abstract reasoning and verbal memory.
"The brain and kidney are both organs that are affected by the cardiovascular systems," said Adam Davey, associate professor of public health in Temple's College of Health Professions and Social Work, who led the study,
Researchers examined longitudinal data, five years apart, from 590 people, according to a statement.
What the researchers found was the greater a person's decrease in renal (kidney) functioning, the greater the decrease in overall cognitive functioning, particularly abstract reasoning and verbal memory.
"They are both affected by things like blood pressure and hypertension, so it is natural to expect that changes in one organ are going to be linked with changes in another," said Davey in a statement.
"Those two tracked together, so this study provides us with evidence that the rate of cognitive decline is associated with deterioration in kidney function" said Davey.
Davey said that this information emphasises two important points: the importance of diagnosing and managing chronic kidney disease and the extent of decrease in cognitive functioning.
"As we get older, our kidney function tends to decrease naturally, so if there's an extra issue involved in renal function like chronic kidney disease, we need to know about it as soon as possible.
"That is something that needs to be managed, just like you would manage hypertension," he said.