Dr. Wangjian Zhang

Sun Yat-sen University, China

Invited Speech: How clinical biomarkers mediate the impact of VD deficiency on the occurrence and severity of COVID-19

Biography:

Associate Professor, Department of Medical Statistics, School of Public Health, Sun Yat-sen University,Guangzhou, China

Dr. Zhang’s work mainly focuses on the statistical modeling of health impact of extreme weather events associated with climate change including extreme heat events, natural disasters as well as consequent social events such as power outages. His research also covers the modeling of the adverse health impact of major air pollutants such as particles and the concentration of its compositions from different sources. Dr. Zhang’s recent work clarifies environmental health issues using state-of-the-art causal inference methods. He and his team improved the framework of assessing the population vulnerability to the health impact of environmental exposures based on the time series analysis and machine learning algorithms. Additionally, his research work also involves the survival analysis, nomogram and interactive online platform for survivorship predictions.

Abstract:

Background: Several studies found that vitamin D deficiency (VDD) reduce COVID-19 infection and severity, but the potential biological pathways remain unclear. This study evaluated how the VDD-COVID occurrence and severity associations were mediated by clinical biomarkers.
Methods: This case-control study compared the VDD rates between 815 healthy controls and 62 patients diagnosed with COVID-19 admitted to our institution, 2/16/2020-3/16/2020. Cases were categorized into mild/moderate and severe/critical disease. We evaluated the mediation effect of biomarkers on the pathway between VDD and COVID-19 related outcomes by using Causal Mediation Analysis. The diagnostic values of biomarkers in predicting risk of COVID-19 infection and severity among VDD individuals was also evaluated by using ROC curves.
Results: VDD rate was significantly higher among COVID-19 patients compared to healthy individuals (41.94% vs 23.68%), and higher among severe cases compared to mild ones (80% vs 34.62%). The VDD-and COVID-19 infection association was mediated by serum hemoglobin, RBC count, total protein, eosinophil, eosinophil ratio, urea nitrogen, and cardiac creatine kinase. The association between VDD and COVID-19 severity was mediated by neutrophil ratio. Among VDD individuals, serum albumin, total protein, hemoglobin were the top predictors of COVID-19 infection (AUC: 0.86-0.97)), and serum albumin, neutrophil ratio, lymphocyte ratio and blood glucose were the top predictors of COVID-19 severity (AUC: 0.91-0.97).
Conclusion: This study suggests that VDD-COVID infection/severity associations may be mediated by concentration of serum protein, hemoglobin, RBC and neutrophil ratio. These biomarkers may play an important role in predicting infections and severity of COVID-19 among VDD individuals.

Abstract

Dr. Wangjian Zhang

Background: Several studies found that vitamin D deficiency (VDD) reduce COVID-19 infection and severity, but the potential biological pathways remain unclear. This study evaluated how the VDD-COVID occurrence and severity associations were mediated by clinical biomarkers.
Methods: This case-control study compared the VDD rates between 815 healthy controls and 62 patients diagnosed with COVID-19 admitted to our institution, 2/16/2020-3/16/2020. Cases were categorized into mild/moderate and severe/critical disease. We evaluated the mediation effect of biomarkers on the pathway between VDD and COVID-19 related outcomes by using Causal Mediation Analysis. The diagnostic values of biomarkers in predicting risk of COVID-19 infection and severity among VDD individuals was also evaluated by using ROC curves.
Results: VDD rate was significantly higher among COVID-19 patients compared to healthy individuals (41.94% vs 23.68%), and higher among severe cases compared to mild ones (80% vs 34.62%). The VDD-and COVID-19 infection association was mediated by serum hemoglobin, RBC count, total protein, eosinophil, eosinophil ratio, urea nitrogen, and cardiac creatine kinase. The association between VDD and COVID-19 severity was mediated by neutrophil ratio. Among VDD individuals, serum albumin, total protein, hemoglobin were the top predictors of COVID-19 infection (AUC: 0.86-0.97)), and serum albumin, neutrophil ratio, lymphocyte ratio and blood glucose were the top predictors of COVID-19 severity (AUC: 0.91-0.97).
Conclusion: This study suggests that VDD-COVID infection/severity associations may be mediated by concentration of serum protein, hemoglobin, RBC and neutrophil ratio. These biomarkers may play an important role in predicting infections and severity of COVID-19 among VDD individuals.