Valoración del estatus de cinc y otros parámetros clínico-nutricionales relacionados, en paciente crítico con respuesta inflamatoria sistémica, con y sin Covid-19

Abstract

Introduction: Critically ill patients are highly susceptible to present and/or develop Zinc (Zn) deficiency during Intensive Care Unit (ICU) stay, especially in generalized inflammatory conditions. However, the assessment of Zn status continues to be a challenge at the present time due to the lack of a reliable biomarker, and, therefore, its relationship with other clinical-biochemical parameters and its effect on patients’ evolution are not completely understood. Objective: To assess Zn status and related clinical-nutritional parameters in critically ill patients with Systemic Inflammatory Response Syndrome (SIRS), with and without COVID-19, at admission and during ICU stay. Methodology: Patients were monitored from the first day of ICU admission until the seventh day of stay or the third day (in the case of patients with COVID-19). In patients without COVID-19, mineral levels (Zn and Selenium (Se)) were analyzed in serum and erythrocyte by flame atomic absorption spectrometry, and Glutathione Peroxidase (GPx) and Superoxide Dismutase (SOD) activity and the Total Antioxidant Capacity (TAC) were measured using kinetic colorimetric methods. In patients with COVID-19, mineral levels were assessed in serum samples by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Methallothioneins (MTs) levels by differential pulse voltammetric. Total 25–hidroxyvitamin D (25–OH–D) levels were measured in plasma samples by liquid chromatography-tandem mass spectrometry in both cases. Results: In patients without COVID-19, vitamin D levels were directly associated with erythrocyte Zn concentration at follow-up. Increases in plasma Se levels, which were low both at admission and at follow-up, were associated with greater changes in SOFA score. GPx activity had inverse correlation to the severity scores at the baseline, while SOD activity was directly correlated to TAC. In patients with COVID-19, 25– OH–D levels were low in all cases at baseline, decreasing during ICU stay. Patients who did not need invasive mechanical ventilation presented higher levels of 25–OH–D2 at baseline and follow-up. Additionally, changes in Zn had a positive effect in respiratory parameters (PaO2/FiO2 and breath ratio). Levels of Copper (Cu) and MTs decreased after 3 days, being changes in MTs inversely related to changes in Manganese (Mn) and albumin. Iron (Fe) and Zn levels were shown to have a predictive value for mortality and severity. Conclusion: In general, the results of the present doctoral thesis indicate a deficient Zn status, as well as other micronutrients deficiencies as vitamin D, Fe, Cu, Se and Mn, which were related to different biochemical, clinical and antioxidant parameters, suggesting a possible beneficial effect of restoring proper levels of Zn and other micronutrients in these patients.