Hartung EA, et al. - In this study, it was investigated if chronic kidney disease (CKD) affects brain structure and if poorer neurocognitive performance in CKD is associated with structural brain differences. Researchers performed advanced quantitative structural magnetic resonance imaging (MRI) and noted that CKD in children and young adults may be associated with lower gray matter (GM) and higher white matter (WM) volumes in some regions of interest (ROIs). They also noted that differences were relatively subtle in the CKD group as a whole, but were more prominent in recipients of a kidney transplant. However, differences in brain ROI volumes failed to explain neurocognitive performance, suggesting a functional rather than structural basis for neurocognitive impairment in CKD.

• In a cross-sectional study design, a total of 85 individuals with CKD stages 2 to 5 and 63 healthy controls, aged 8 to 25 years, were examined.
• As predictors of MRI findings, CKD vs control, estimated glomerular filtration rate (eGFR), and kidney transplant status were analyzed.
• Furthermore, MRI volumes in 19 prespecified regions of gray matter (GM), white matter (WM), and cerebrospinal fluid were analyzed as predictors of neurocognitive performance (median z scores) in 7 prespecified domains.
• Outcomes included 19 prespecified brain regions of interest (ROIs) in 7 prespecified domains, and neurocognitive performance in 7 prespecified domains.
• Using unadjusted t tests and analysis of covariance (ANCOVA), comparison of ROI volumes was performed among CKD vs controls.
• Additionally, using ANCOVA and linear regression, associations of ROI volumes with eGFR and kidney transplant status in participants with CKD were analyzed.
• Researchers used linear regression to analyze associations of neurocognitive performance and ROI volumes.

• In unadjusted analyses, lower whole-brain, cortical, and left parietal GM volumes were seen among participants with CKD vs controls, but no differences were found in adjusted analysis.
• Association of lower eGFR with higher WM volume in whole-brain (P=0.05) and frontal (P=0.04) ROIs was apparent among participants with CKD, but differences were not significant after multiple comparisons correction.
• Researchers noted that kidney transplant recipients had lower GM volumes in whole-brain (P=0.01; Q = 0.06), frontal (P=0.02; Q = 0.08), and left and right parietal (P=0.01; Q = 0.06; and P=0.03; Q = 0.1) ROIs and higher whole-brain WM volume (P=0.04; Q = 0.1).
• In addition, they noted that neurocognitive performance in the CKD group was not associated with ROI volumes.