Plasma zinc status and hyperinflammatory syndrome in hospitalized COVID-19 patients: an observational study

Deficiency of the element zinc is associated with cytokine releasing syndrome (CRS) and the related acute respiratory distress syndrome as well as impaired antiviral response. Similar complications associate with severe SARS-CoV-2. We conducted a prospective, single-center, observational study in a tertiary university hospital (CUB-Hopital Erasme, Brussels) to address the zinc status, the association between the plasma zinc concentration, development of CRS, and the clinical outcomes in PCR-confirmed and hospitalized COVID-19 patients. One hundred and thirty-nine eligible patients were included between May 2020 and November 2020 (median age of 65 years [IQR, 54 to 77]). Our cohort’s mean plasma zinc concentration was 56.2 µg/dL (standard deviation [SD], 14.8) compared to 75.7 µg/dL (SD = 18.9 µg/dL) in the retrospective non-COVID-19 control group (N = 1513; P <.001). Markedly, the absolute majority of patients (96%) were zinc deficient (<80 µg/dL). The mean zinc concentration was lower in patients with CRS compared to those without CRS (−5 µg/dL; 95% CI, -10.5 to 0.051; P = 0.048). Among the tested outcomes, zinc concentration is significantly correlated with only the length of hospital stay (rho = -0.19; P = 0.022), but not with mortality or morbidity. As such, our findings do not support the role of zinc as a robust prognostic marker among hospitalized COVID-19 patients who in our cohort presented high prevalence of zinc deficiency. It might be more beneficial to explore the role of zinc as a biomarker for assessing the risk of developing a tissue-damaging CRS and predicting outcomes in patients diagnosed with COVID-19 at the early stage of the disease.