Predominant gray matter volume loss in patients with end-stage renal disease: a voxel-based morphometry study

To investigate the pattern of brain volume changes in patients with end-stage renal disease (ESRD) using voxel-based morphometry (VBM) and correlation with clinical and neuropsychological (NP) tests. Fifty seven ESRD patients with no anatomical abnormalities in conventional magnetic resonance imaging [24 patients with abnormal NP scores, 16 male, 39 +/- 12 years; 33 patients with normal NP scores, 23 male, 35 +/- 9.7 years] and 22 age- and gender-matched healthy controls (14 male, 36 +/- 10.1 years) were recruited in this study. Results from VBM analysis were analyzed with ANOVA test among 3 groups (controls, minimal nephro-encephalopathy group, non-nephro-encephalopathy group). Multiple linear regression analysis was used to investigate the effect of serum urea and creatinine, and dialysis duration on the brain volumes in ESRD patients. Correlation analysis was performed to investigate the association between NP scores with the brain volumes in ESRD patients. Compared with healthy controls, ESRD patients showed diffusely decreased gray matter volume that further decreased in the presence of encephalopathy. Multiple linear regression results showed that serum urea was negatively associated with changes in gray matter volume in many regions, while dialysis duration was negatively associated with some white matter volume changes (All P < 0.05, AlphaSim correction). NP scores correlated with some decreased gray matter volume in ESRD patients (All P < 0.05, AlphaSim correction). No correlation was found between white matter volume and any NP test scores in ESRD patients. This study found predominantly decreased gray matter volume in ESRD patients, which was associated with neurocognitive dysfunction. Serum urea level may be a risk factor for decreased gray matter in ESRD patients.