Clinical Relevance of Malnutrition-Inflammation Score in Detecting Peritoneal Sclerosis Among Long-Term Peritoneal...

The malnutrition-inflammation score (MIS) is a composite indicator widely used in dialysis populations to evaluate nutritional deficiency and chronic inflammation. However, its association with structural peritoneal alterations remains unclear. This study aimed to investigate the relationship between MIS and the peritoneal sclerosis index (PSI) in long-term peritoneal dialysis (PD) patients.

This single-center cross-sectional study included 191 PD patients with dialysis duration≥3 years. MIS was assessed using a standardized scoring system, and PSI was quantified based on structural abnormalities identified on abdominal computed tomography (CT). In response to the reviewer comment, beta2-microglobulin was additionally incorporated into the comparative analysis together with dialysis vintage, age, peritoneal equilibration test score, and dialysis adequacy. The association between MIS and CT-defined peritoneal sclerosis was evaluated using Spearman correlation, multivariate linear regression, and logistic regression analyses, and an exploratory screening of other candidate clinical indicators associated with PSI was also performed.

When PSI was used as the CT-based marker of peritoneal sclerosis, dialysis vintage showed the strongest correlation with PSI (r = 0.333, P < .001). MIS showed only a weak correlation with PSI (r = 0.114, P = .116), whereas beta2-microglobulin was also weakly correlated (r = 0.154, P = .034). In univariate logistic analysis, MIS was associated with clinically significant peritoneal sclerosis (PSI≥5; odds ratio 1.13, P = .017), but this association was attenuated after adjustment for dialysis vintage, age, peritoneal equilibration test score, dialysis adequacy, and beta2-microglobulin. Exploratory analysis further showed that lower urine output and higher PD volume were associated with higher PSI values.

MIS may be clinically useful as a composite risk-stratification marker reflecting malnutrition-inflammatory burden and systemic vulnerability, rather than as an independent specific predictor of CT-defined peritoneal sclerosis. In this cohort, dialysis vintage remained the most stable correlate of CT-defined sclerosis burden, while beta2-microglobulin provided only limited additional discriminatory value.