Prevalence of Malnutrition Inflammation Complex Syndrome among adult Chronic Kidney Disease patients on dialysis – a Systematic review and Meta-analysis

Introduction: Malnutrition-Inflammation Complex Syndrome (MICS) is a common and serious complication among chronic kidney disease (CKD) patients undergoing dialysis, linked to increased morbidity and mortality. However, the reported prevalence rates vary widely due to differences in diagnostic criteria and study populations. This systematic review and meta-analysis aimed to estimate the global prevalence of MICS in adult CKD patients on dialysis and to investigate sources of variability in reported prevalence. Methods We conducted a comprehensive search of PubMed, Embase, Scopus, and Web of Science for observational studies assessing MICS prevalence using the Malnutrition-Inflammation Score (MIS). Studies were included if they involved adult CKD patients on renal replacement therapy. Data extraction, risk of bias assessment, and meta-analysis using a random-effects model were performed. Subgroup analyses and meta-regression explored heterogeneity, particularly related to diagnostic thresholds. Results Eleven studies comprising 3,788 patients were included. The pooled prevalence of MICS was 58% (95% CI 40–75), with significant heterogeneity (I²=98.6%). Stratifying by diagnostic criteria, studies using MIS score cut-offs below 6 reported a higher prevalence (80%; 95% CI 41–100) compared to studies using cut-offs ≥ 6 (44%; 95% CI 29–60). Diagnostic threshold accounted for 44% of heterogeneity. Sensitivity analyses confirmed robustness, and no significant publication bias was detected. Conclusions MICS affects more than half of CKD patients on dialysis, although prevalence estimates vary considerably depending on diagnostic criteria. This highlights the urgent need for standardized, consensus-based diagnostic approaches to reliably assess and address MICS globally. Our findings provide a foundation for developing targeted screening, treatment, and prevention strategies to improve patient outcomes.