Association of Malnutrition, Inflammation, and Residual Kidney Clearance in Peritoneal Dialysis: A Cross-Sectional Analysis.

BACKGROUND: Malnutrition and systemic inflammation are common and interrelated complications in patients undergoing peritoneal dialysis (PD), contributing to poor clinical outcomes. Residual kidney clearance (Kr) may play a protective role in this context, while erythropoietin resistance index (ERI) reflects anemia management challenges influenced by inflammation. This study aimed to investigate the associations of nutritional and inflammatory markers with Kr and ERI in PD patients. METHODS: We conducted a cross-sectional study of 47 stable adult PD patients. Nutritional and inflammatory indicators, including Malnutrition Inflammation Score (MIS), serum albumin, and Interleukin-6 (IL-6), were assessed alongside Kr and ERI. Linear regression analysis was used to evaluate associations, and Spearman correlation with bootstrapped 95% confidence intervals determined relationships among clinical variables. RESULTS: The mean age was 62.2 ± 15.5 years; 53.2% were male. The mean MIS was 5.7 ± 2.5, serum albumin 3.29 ± 0.5 g/dL. IL-6 was positively associated with MIS (β = 0.684, p = 0.037). Kr was significantly inversely associated with MIS (β = -0.585, p = 0.040) and positively associated with serum albumin (β = 0.152, p = 0.018). Spearman analysis confirmed significant correlations between Kr and both MIS (r = -0.358, p = 0.008) and albumin (r = 0.343, p = 0.012), and between IL-6 and MIS (r = 0.390, p = 0.004). ERI showed no significant correlations with MIS, albumin, IL-6, or Kr. CONCLUSION: MIS was significantly associated with IL-6, highlighting the close relationship between malnutrition and systemic inflammation in patients undergoing PD. Higher Kr was associated with a more favorable nutritional inflammatory profile, whereas no significant associations were observed for ERI.