Analysis of the predictive factors for a critical illness of COVID-19 during treatment － relationship between serum zinc level and critical illness of COVID-19

Abstract

Objectives: Because most severely ill patients with COVID-19 in our hospital showed zinc deficiency, we aimed to examine the relationship between the patient's serum zinc level and severe cases of COVID-19.

Methods: Serum zinc <70 μg/dL was defined as the criterion for hypozincemia, and patients continuously with serum zinc <70 μg/dL were classified in the hypozincemia cohort. To evaluate whether hypozincemia could be a predictive factor for a critical illness of COVID-19, we performed a multivariate analysis by employing logistic regression analysis.

Results: Prolonged hypozincemia was found to be a risk factor for a severe case of COVID-19. In evaluating the relationship between the serum zinc level and severity of patients with COVID-19 by multivariate logistic regression analysis, critical illness can be predicted through the sensitivity and false specificity of a ROC curve with an error rate of 10.3% and AUC of 94.2% by only two factors: serum zinc value (P = 0.020) and LDH value (P = 0.026).

Conclusions: Proper management of the prediction results in this study can contribute to establishing and maintaining a safe medical system, taking the arrival of the second wave, and the spread of COVID-19 in the future into consideration.

Keywords: COVID-19; Critical illness; Japan; Logistic regression analysis; Predictive factors; Serum zinc.