Resting-state fMRI reveals immediate hemodialysis-related changes in cognitive function and brain network connectivity in end-stage renal disease

End-stage renal disease (ESRD) is associated with an increased risk. This study investigates associations between cognitive decline, resting-state networks (RSNs), and biochemical indicators in ESRD patients pre-/post-hemodialysis. 20 hemodialysis (HD) patients and 22 healthy controls underwent resting-state fMRI (rs-fMRI) and neuropsychological assessments. Resting-state networks (RSNs) were extracted via independent component analysis (ICA), with functional connectivity strength compared between pre-/post-HD patients and controls. Correlations between connectivity strength and biochemical indicators were analyzed. Compared to HCs, the post-HD group exhibited significantly decreased FC between the auditory-somatomotor network (t = - 5.120, P < 0.001) and the visual-somatomotor network (t = - 4.199, P < 0.001). In contrast, FC between the default mode and dorsal attention networks was significantly increased (t = 2.908, P = 0.006). While serum electrolytes and iron metabolism markers remained stable post-HD (all P > 0.05), phosphorus levels decreased (P = 0.046), with significant improvements in renal function: eGFR increased from 4.560 ± 1.650 to 16.980 ± 6.428 mL/min, urea, creatinine, and PTH levels decreased (all P < 0.001). Elevated baseline chloride levels were associated with reduced post-HD attention network connectivity (r = -0.758, P < 0.001), while cognitive improvement correlated inversely with baseline connectivity (r = -0.619, P = 0.004) and positively with connectivity plasticity (r = 0.513, P = 0.021). Immediate post-HD changes in resting-state network connectivity were associated with biochemical status and cognitive performance, suggesting potential neural substrates of cognitive dysfunction in ESRD.