Association between protein-energy wasting and cognitive impairment in maintenance hemodialysis patients

This study aimed to investigate the association between protein-energy wasting (PEW) and cognitive impairment (CI) in patients undergoing maintenance hemodialysis (MHD).

In this single-center cross-sectional study, 86 patients receiving MHD were enrolled. Nutritional status was assessed using anthropometric measurements, including mid-arm circumference (MAC) and mid-arm muscle circumference (MAMC), as well as the Malnutrition-Inflammation Score (MIS). Cognitive function was evaluated with the Montreal Cognitive Assessment (MoCA), with patients classified into CI (n = 50) and non-CI (n = 36) groups based on education-adjusted scores. Group comparisons, Spearman correlation analysis, multivariable logistic regression, and receiver operating characteristic (ROC) curve analysis were performed.

Cognitive impairment was present in 58.1% of the patients. Compared with the non-CI group, patients with CI had a higher Malnutrition-Inflammation Score and lower MAMC. Multivariable logistic regression analysis showed that lower MAMC (adjusted OR 0.571, 95% CI 0.400-0.816, p = 0.002) and higher MIS (adjusted OR 1.249, 95% CI 1.006-1.550, p = 0.044) were independently associated with cognitive impairment. ROC analysis demonstrated that a multivariable model combining age, years of education, dialysis vintage, MAMC, and MIS exhibited excellent discriminative ability (AUC = 0.942, 95% CI 0.898-0.987).

Lower MAMC and higher MIS were independently associated with cognitive impairment in patients undergoing maintenance hemodialysis. These two indicators (MAMC and MIS) showed stronger and more consistent associations with cognitive impairment than single biochemical markers. Given the cross-sectional design of the study, the temporal direction of the association cannot be determined. Prospective studies are warranted to clarify whether muscle loss precedes cognitive decline or occurs as a consequence of it, and to evaluate whether preserving muscle mass can protect cognitive function in this population.