Predictors factors of COVID-19-associated mortality in dialysis patients: Importance of nutritional status

Abstract

Background Patients with comorbidities, such as chronic renal disease, are susceptible to severe COVID-19 infection. Dialysis patients have a high prevalence of malnutrition, and it has been demonstrated association between nutritional status and several unfavorable outcomes in this population. The aim of this study was to assess nutritional status through Malnutrition-Inflammation Score (MIS) and phase angle (PhA), along with demographic and biochemical indicators and verify whether they are predictive variables of outcomes in dialysis patients with COVID-19 infection. Methods An observational, retrospective, cross sectional type study was undertaken in a Nephrology and Dialysis center in a tertiary hospital at São Paulo city. We evaluated data from EMR from 37 dialysis patients who had COVID-19 infection (RT-PCR) between march 2020 and december 2021. A Logistic regression was used in order to evaluate risk factors associated with mortality. Then we compared with a cohort of 31 dialysis patients infected with COVID-19 in the post-vaccionation period. Results Regarding MIS, age, and phase angle (PhA), we observed that for each unit increase in MIS previously to COVID-19 infection, there was a 30% increase in mortality risk (adj OR = 1.3, CI 1.0-1.8, p = 0.068) and that patients above 65 years had 8 times higher chance to die (adj OR = 8.8, CI 0.8–102, p = 0.082). Yet, for each unit increase in PhA, there was a 50% decrease in death risk (adj OR = 0.5, IC 0.2–1.1, p = 0.097), although no significance was found after logistic regression. After immunization, we found a attenuation of impact of nutritional status after COVID-19 infection, as demonstrated by a small, non-significant increase in MIS score, and with a low hospitalization need and no death. Conclusions The present study demonstrated a trend that age is the main variable determining outcomes of COVID-19 infection in dialysis patients. Besides that, we demonstrated the importance of nutritional status (MIS e PhA), since it appears to increase mortality risk when baseline nutritional status is worse and compromised after the COVID-19 infection, which was clearly abrogated with vaccination.