MO695: Phase Angle: Clinical and Prognostic Value in Peritoneal Dialysis

Abstract

Abstract BACKGROUND AND AIMS Malnutrition–inflammation–atherosclerosis syndrome is common in chronic kidney disease and is associated with high mortality, particularly in dialysis patients. Bioimpedance analysis (BIA) is a simple and non-invasive method for nutritional assessment. The aim of this study was to evaluate the relationship between phase angle (PA) and other nutritional parameters and establish its role as predictor of mortality in peritoneal dialysis (PD) patients. METHOD Prevalent PD patients were enrolled in the longitudinal prospective study in a single tertiary center between 2015 and 2020, with a simultaneous BIA assessment and a modified peritoneal equilibration test. Spearman's correlation test was used to assess relevant clinical associations. Survival analysis was performed using the Kaplan–Meier test and univariate and multivariate Cox analysis to determine the predictive factors of all-cause mortality. RESULTS A total of 49 PD patients were included with mean age 55.9 ± 16.2 years, 57.1% male, Charlson comorbidity index 4.9 ± 2.3, Kt/V 2.5 ± 0.7, with a mean follow-up of 39.9 ± 26.3 months. The Spearman's correlation test showed a very strong positive association between PA and extracellular mass/body cell mass (r = 0.939, P < 0.001). It also showed a moderate positive association between PA and albumin (r = 0.524, P < 0.001) and normalized protein catabolism rate (r = 0.437, P = 0.002). Furthermore, PA was negatively correlated with age (r = −0.477, P = 0.001). In the Kaplan–Meier analysis, patients with PA < 4.9° had a lower survival rate (log rank = 4.77; P = 0.029). Using the multivariate Cox regression, forward model, PA (HR = 0.243; 95% CI 0.079–0.753), the number of cardiovascular events (HR = 11.236; 95% CI 1.286–98.211) and neutrophil–lymphocyte ratio (HR = 1.360; 95% CI 1.033–1.790) were predictors of all-cause mortality. CONCLUSION Lower PA appears to be associated with a decline in nutritional status, so monitoring it can be useful to identify patients at higher risk of malnutrition. PA was also validated as an independent predictor of mortality in our PD patients.