Mild cognitive impairment is associated with effect of uremic metabolites on gray matter structural changes in end-stage kidney disease

To investigate the grey matter volume (GMV) changes and uremic metabolites in end-stage kidney disease (ESKD) patients with mild cognitive impairment (MCI) (ESKD-MCI) and further examine the classification and diagnostic efficacy of these features for ESKD-MCI patients. A total of 65 patients with ESKD, including 34 ESKD-MCI and 31 with non-cognitive impairment (ESKD-NCI), and 55 health controls (HCs) were enrolled. All participants underwent brain structural magnetic resonance imaging (MRI) scanning and Montreal cognitive assessment test. Clinical characteristics and GMV differences among these three groups were analyzed. In addition, mediation analysis was performed to determine the mediating effect of GMV changes on the association between clinical risk factors and MCI. Finally, support vector machine were employed to examine the classification and diagnostic efficacy of GMV changes and clinical features for MCI. Both patient groups exhibited widespread structural brain injury compared with the HCs. Moreover, compared with ESKD-NCI, ESKD-MCI patients demonstrated reduced GMV specifically in the left middle temporal gyrus and inferior temporal gyrus. Notably, these GMV changes completely mediates the effect of serum phosphorus levels on MCI. Furthermore, imaging features rather than serum phosphorus levels had good classification and diagnostic efficacy for ESKD-MCI. Our findings underscore the significance of the left temporal gyrus as a pivotal brain region in ESKD-MCI patients, fully mediating the link between uremic metabolite and MCI. GMV alterations presents a promising avenue for effectively detecting MCI in individuals with ESKD.