Kidney complications in young adulthood linked to risk for cognitive decline at midlife
Young adults who experienced episodes of kidney function decline – termed here as having greater end-stage renal disease risk exposure – had lower cognitive performance at middle age, according to a study published in Neurology.
“Prevalence of cognitive impairment is approximately threefold higher in ESRD patients than the age-matched general population,” Sanaz Sedaghat, PhD, of the department of preventive medicine at Northwestern University Feinberg School of Medicine, and colleagues wrote. “More recent evidence indicates that cognitive impairment is not limited to patients with ESRD and even mild to moderate degrees of kidney impairment can be toxic for the brain and increase the risk of cognitive decline. A limitation of most studies is that kidney function is measured once in later life, which does not account for the adverse influence of long-term and repeated exposures to kidney dysfunction.”
To address this limitation, Sedaghat and colleagues assessed kidney function during the course of 20 years in 2,604 participants from the Coronary Artery Risk Development in Young Adults study (mean age, 35 years; 54% were women; 45% were Black).
Researchers determined ESRD risk exposure through the Kidney Disease: Improving Global Outcomes guidelines (eGFR <60 mL/min/m2 and/or albumin-to-creatinine ratio > 30), categorizing patients as consistent low risk (no episodes); one episode of moderate, high or very high ESRD risk (5% with one high/very high episode); or more than one episode of moderate, high or very high risk during follow-up (55% had at least one high/very high episode).
All participants underwent global and multi-domain cognitive assessment at year 30, with 16% of the study population having one or more episode of ESRD risk exposure during the course of 20 years.
After controlling for demographic status and cardiovascular risk factors, Sedaghat and colleagues found people with higher risk episodes had lower composite cognitive function, psychomotor speed and executive function.
Additional results showed participants with constant decline in their kidney function performed worse in cognitive function than those with stable risk over time or those who recovered from one or two episodes of moderate/high ESRD risk.
Sedaghat and colleagues contended that these findings, suggesting an association between kidney function and cognitive impairment at a young stage in life, warrant “clinical attention and further investigation.”
“Dementia is a devastating medical condition and extensive efforts to treat this clinical entity have been unsuccessful,” the researchers concluded. “This calls for early prevention of cognitive decline decades before full-blown manifestation of dementia. Our finding highlights the importance of early detection of kidney dysfunction and implementation of appropriate interventions to prevent adverse brain function in later life.”