We’ve known for some time that chronic kidney disease (CKD) is associated with hypertension and other heart problems, anemia (deficiency of red blood cells), systemic inflammation, and oxidative stress.
But the effect of CKD on the brain hasn’t been studied a lot till now. Because a new study published in the journal Neuropsychiatric Disease and Treatment reveals that people with CKD are up to 600 percent more likely to suffer a specific type of cognitive impairment.
A team of Ethiopian researchers noted that CKD patients were more likely than the general population to have conditions that had previously been associated with cognitive impairment, such as hypertension and other heart problems, anemia (deficiency of red blood cells), systemic inflammation, and oxidative stress.
As a result, they wondered whether people with CKD had an elevated risk of developing cognitive impairment.
To find out, they recruited 116 CKD patients from the University of Gondar Comprehensive Specialized and Felege Hiwot Referral Hospitals. In addition, they asked 116 caregivers who accompanied patients to the hospitals to serve as a control group.
They used the patients’ glomerular filtration rate to diagnose their kidney disease, and also recorded their level of cognitive function with the commonly used Mini Mental State Examination tool.
In addition, they recorded their subjects’ weight, blood pressure, protein in the urine, red blood-cell count, drinking and smoking status, khat-chewing status, level of social support, and diabetes and cardiovascular disease status.
The Mini Mental State Examination tool scores our cognitive function out of 30. It is divided into orientation (10 points), language and praxis (nine points), attention and calculation (five points), registration (three points), and recall (three points).
Orientation is the ability to relate your personality and behavior to other people, times, and places. Praxis is your ability to carry out learned behaviors that involve intentional movements. Registration is your ability to notice and memorize, in the short term, things that you come across.
The researchers found that 49.1 percent of the CKD patients had cognitive impairment, compared with 28.4 percent of the healthy subjects.
On average, the CKD patients scored two points lower on the Mini Mental State Examination tool.
Those with the most severe CKD and the highest protein levels in their urine (a sign of CKD) were the most likely to struggle with cognitive function: their scores were respectively 3.9 times and six times as bad as those with less severe CKD and those with normal protein excretion.
The elderly and those with low levels of education also had a larger risk, with cognitive impairment being four times more likely in the over-65s than in the under-65s, and being 4.7 times more likely in those with only eighth grade-level education than those with college-level education.