Early detection of mild to moderate kidney disease is an important public-health concern with regard to cognitive decline, concluded researchers who found that reductions in estimated glomerular filtration rate (eGFR) values were associated with declines in cognitive function in a five-year longitudinal study of 590 community-living individuals.
Previous research has shown decreased eGFR and higher serum creatinine levels to be associated with longitudinal decline in global mental-status measures. A team led by Adam Davey, of Temple University’s College of Health Professions and Social Work, launched the current study (published online ahead of print in Nephrology Dialysis Transplantation) to determine which specific abilities are most affected in persons with impaired renal function.
The study subjects (mean age 62.1 years; mean eGFR 78.4 mL/min/1.73m2) were free of dementia, acute stroke, and end-stage renal disease at baseline. Changes in the participants’ renal functioning over time were related to changes observed in global cognitive ability, verbal episodic memory and abstract reasoning.
The relationship between declines in kidney function and in cognitive function persisted even after statistical adjustments were made for demographic variables and cardiovascular disease risk factors, and after persons who developed dementia or experienced an acute stroke were excluded.
“The brain and kidney are both organs affected by the cardiovascular systems,” the researchers wrote. “They are both affected by things like blood pressure and hypertension, so it’s natural to expect that changes in one organ are going to be linked with changes in another.”