Combining hemodialysis with peritoneal dialysis improves cognitive function: a three-case report

Chronic kidney disease (CKD) is associated with multiple complications, with recent scholarly attention underscoring cognitive impairment as a salient manifestation. Considering societal aging, preserving cognitive function has emerged as an urgent medical concern. Prolonged dialysis, encompassing hemodialysis (HD) and peritoneal dialysis (PD), has been associated with a decline in cognitive function. Here, we present the cases of three patients undergoing PD who exhibited a noticeable improvement in cognitive function upon the initiation of HD. One patient had exhibited mild cognitive decline, whereas the remaining two presented more severe impairment. Apart from a mild tendency for fluid retention, none of the three patients exhibited abnormalities in physical or imaging examinations. Evaluation using the Japanese version of the Montreal Cognitive Assessment (MoCA-J) yielded decreased scores across multiple domains, notably in executive and attention functions. However, after HD initiation, all patients demonstrated a marked enhancement in multiple MoCA-J parameters, accompanied by a significant improvement in subjective symptoms. Moreover, improvements in anemia and hypoalbuminemia were observed in all three patients, whereas consistent trends in other parameters were absent. These clinical observations suggest that the integration of HD into the therapeutic regimen of patients undergoing PD may enhance cognitive function, highlighting the contributory roles of hemoglobin and albumin in CKD-associated cognitive impairment.