Kidney function and brain health: cognitive and structural signatures across cohorts

Chronic kidney disease (CKD) is linked to cognitive decline, yet the roles of estimated glomerular filtration rate (eGFR) and its variability remain unclear.

We analyzed 6847 adults from two population-based cohorts (the Multimodality MEdical imaging sTudy bAsed on KaiLuan Study [META-KLS], UK Biobank) and 426 CKD patients from Beijing Friendship Hospital (BFH)-CKD. Exposures included eGFR level and variability. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA) and brain structure by magnetic resonance imaging (MRI).

In META-KLS, higher cumulative eGFR was associated with higher MoCA scores (β = 0.350; 95% confidence interval [CI]: 0.148 to 0.552), whereas greater eGFR variability was associated with lower MoCA scores (β = -0.454; 95% CI: -0.659 to -0.250). Across cohorts, higher eGFR was associated with white matter, superior frontal, and middle temporal volumes. In META-KLS, greater variability showed nominal inverse associations with inferior parietal and middle temporal volumes and reduced rostral anterior cingulate cortex thickness.

Lower eGFR and greater eGFR variability were associated with lower MoCA scores and region-specific structural brain alterations.