Brain white matter microstructure in end-stage kidney disease, cognitive impairment, and circulatory stress.
INTRODUCTION
Structural and functional brain white matter abnormalities are poorly characterized in patients with end-stage kidney disease.


METHODS
We examined the prevalence of the brain white matter microstructure disruption using diffusion tensor magnetic resonance imaging and its association with hemodynamic performance and cognitive defects in 49 incident hemodialysis (HD) patients and compared these to 25 age-matched normal controls. We analyzed fractional anisotropy (FA) and mean diffusivity (MD) maps of the images, a voxelwise statistical analysis was done using tract-based spatial statistics. Hemodynamic assessment was done using extrema points analysis model of continuous blood pressure monitoring.


FINDINGS
We found significant white matter damage in HD patients compared with normal controls (peak FA 0.471 ± 0.031 vs 0.486 ± 0.022 P = 0.023, peak MD 0.00194 ± 0.000363 10-3 mm2 .s-1 vs 0.00167 ± 0.0003 10-3 mm2 .s-1 P = 0.002). There was diffuse pattern of white matter damage in HD patients, which was independent of age, gender, and the presence of ischaemic heart disease and diabetes with significantly lower FA values in HD patients than normal controls (0.467 ± 0.037 vs 0.507 ± 0.026, P < 0.05 corrected for family wise error. HD patients had worse cognitive scores that correlated with white matter damage (for peak FA, Montreal cognitive assessment r = 0.478 P = 0.001, Trail A r = -0.486 P = 0.001, Trail B r = -0.464 P = 0.001; for peak MD, Montreal cognitive assessment r = -0.533 P < 0.001, Trail A r = 0.641 P < 0.001, Trail B r = 0.514 P < 0.001). In a multivariable linear regression analysis that included age, smoking, the presence of ischaemic heart disease, and diabetes mellitus, higher frequency of mean arterial blood pressure extrema points during HD was independently associated with white matter damage (β = -0.296, P = 0.036, Adjusted R2 for the whole model = 0.400).


DISCUSSION
End-stage kidney disease patients on HD have more brain white matter damage and cognitive impairment than age-matched controls that are linked to hemodynamic functional measures.
['Eldehni|Mohamed T|MT|', 'Odudu|Aghogho|A|', 'Mcintyre|Christopher W|CW|']
D000293:Adolescent D000328:Adult D000368:Aged D000369:Aged, 80 and over D001921:Brain D060825:Cognitive Dysfunction D056324:Diffusion Tensor Imaging D005260:Female D006801:Humans D007676:Kidney Failure, Chronic D008137:Longitudinal Studies D008297:Male D008875:Middle Aged D006435:Renal Dialysis D066127:White Matter D055815:Young Adult
circulatory stress diffusion tensor magnetic resonance imaging hemodialysis cognitive function