The relationship between nutritional and inflammatory status inhemodialysis patients and cardiovascular outcomes and mortality

Hemodialysis (HD) is the most frequently applied renal replacement therapy for patients diagnosed with end-stage renal disease (ESRD). Cardiovascular risk and related mortality in HD patients are known to be associated with malnutrition and inflammation. However, parameters like C-reactive protein (CRP), albumin, and leukocytes commonly used to evaluate these conditions in practice are considered insufficient for accurately assessing patients' nutritional and inflammatory statuses. This study aims to investigate the relationship between values calculated based on laboratory data, such as Controlling Nutritional Status (CONUT) score, Prognostic Nutritional Index (PNI), Nutritional Risk Index (NRI), Systemic Immune-Inflammation Index (SII), Monocyte/Lymphocyte Ratio (MLR), and Neutrophil/Lymphocyte Ratio (NLR), and cardiovascular outcomes and mortality in HD patients. This retrospective study was conducted between January 1, 2023, and January 1, 2024, on patients aged 18 and older who had received hemodialysis treatment for at least three months at Alanya Training and Research Hospital, Başkent University Alanya Research and Application Center, and Private Alanya Can Dialysis Center. Data including physicians' notes, laboratory results, medical imaging records, dialysis data, and pathology reports were collected from the hospitals' automation systems. The first set of parameters, calculated from January 2023 laboratory data, was labeled as "A," while the second set, calculated from January 2024 data or the last available data before death (for deceased patients), was labeled as "B." Relationships between patients' mortality and cardiovascular outcomes and their CONUT score, PNI, NRI, NLR, MLR, and SII were examined. The study included 244 cases (96 females [39.3%] and 148 males [60.7%]) aged between 22 and 88 years. Patients were categorized into four groups: survivors, deceased, those with newly developed cardiovascular events, and those without. A total of 31 patients (12.7%) had died, while 213 (87.3%) were alive. Cardiovascular events developed in 22 patients, whereas 222 did not experience new events. Patients with higher MLR values had significantly higher mortality rates, with a cutoff point of ≥0.36 (sensitivity 84.2%; specificity 62.4%). Similarly, higher NLR values were associated with increased mortality (cutoff ≥3.43; sensitivity 86.8%; specificity 53.1%). Elevated SII was also linked to higher VIII mortality (cutoff ≥725.2; sensitivity 81.6%; specificity 48.4%). PNI and NRI values were inversely related to mortality, with cutoff points of ≥8.95 (sensitivity 75.6%; specificity 63.2%) and ≥45.24 (sensitivity 65.3%; specificity 57.9%), respectively. Mortality rates were stratified based on CONUT score levels, with significant differences observed: normal (1.3%), mild (8.6%), moderate (31.1%), and severe malnutrition (85.7%) (p<0.001). Regarding cardiovascular outcomes, MLR and NLR cutoff points were ≥0.36 (sensitivity 77.3%; specificity 36.5%) and ≥3.9 (sensitivity 68.2%; specificity 52.3%), respectively. While SII was significant in chi-square analysis, it was not significant in ROC curve analysis (p=0.061). In 2024 data (value B), the frequency of cardiovascular events was 3.9% and 7.8% in the normal and mild malnutrition groups, respectively, and 19.2% in the moderate to severe malnutrition group, with a significant correlation between higher CONUT scores and cardiovascular event frequency (p=0.010). Mortality rates were significantly higher in patients with hypertension (p<0.001). Significant associations were identified between inflammation parameters (MLR, NLR, and SII) and cardiovascular outcomes and mortality in HD patients. Nutritional parameters (PNI, CONUT, and NRI) were significantly linked to mortality, with cardiovascular outcomes being notably associated only with the CONUT score. These findings suggest that clinicians should consider these parameters in the evaluation of HD patients, as they could serve as early indicators of cardiovascular disease and mortality. Keywords: mortality, hemodialysis, Prognostic Nutritional Index, Nutritional Risk Index, Controlling Nutritional Status (CONUT) score, Systemic Immune-Inflammation Index, Monocyte/Lymphocyte Ratio, Neutrophil/Lymphocyte Ratio