key: cord-0775941-5uk2q0kl
authors: nan
title: Fasting blood glucose predicts the occurrence of critical illness in COVID-19 patients: a multicenter retrospective cohort study
date: 2020-07-08
journal: J Infect
DOI: 10.1016/j.jinf.2020.07.006
sha: 82935b80412c19269f034b91bcca2558829028b2
doc_id: 775941
cord_uid: 5uk2q0kl

nan

We read the recent published article by Lin and colleagues in journal of infection with great interest, which reported that serum ferritin as an independent risk factor for severity in COVID-19 patients (1) . Previous studies aimed to identification risk factors of critical or mortal condition of patients with COVID-19 from clinical, laboratory, and radiological characteristics at admission (2) . Early warning of patients who are most likely to develop critical disease will enable informed decisions, and facilitate the provision of timely supportive treatment in advance and thus reduce mortality. In this multicenter retrospective cohort study, we aimed to explore the value of admission fasting blood glucose (FBG) in predicting the occurrence of critical illness among patients hospitalized for COVID-19.

We enrolled a total of 123 laboratory-confirmed COVID-19 patients from three designated hospitals of Wuhan and Guangzhou, China. We collected clinical and laboratory data at hospital admission from medical records. We defined the severity of COVID-19 according to the newest COVID-19 guidelines released by the National Health Commission of China (2) and the guidelines of American Thoracic Society for community-acquired pneumonia (3) . We defined critical illness as a composite of admission to the intensive care unit (ICU), respiratory failure requiring mechanical ventilation, septic shock during hospitalization, or death. The optimal cutoff of FBG for discriminating COVID-19 patients with non-critical and critical illness was determined using receiver operating characteristic (ROC) curve and by maximizing the Youden index. To identify predictors for critical illness, baseline variables with p-value <0.10 in univariable analysis were entered into multivariate logistic regression. In addition, Pearson correlation coefficient was used to determine the correlation between FBG and other laboratory parameters. The retrospective study was approved by an ethics committee of our institution, with a waiver of informed consent.

The proportion of critical patients was 31.7% (39/123). The relatively high critically ill rate seen in this study was related to the fact that the First Affiliated Hospital of Guangzhou Our study suggested that elevated FBG at admission is a crucial risk factor for critical illness in COVID-19 patients, although most patients (82.9%) had no previous diabetes, which was consistent with previous studies (5, 6). After adjusting for previous diabetes, the OR of FBG level was not significantly changed. The proportion of hyperglycemia was higher than a previous report of 47.2% (7), which may be due to the higher rate of critically ill patients we included. Except for well-known diabetes, elevation of FBG level at admission could also due to stress hyperglycemia. Stress hyperglycemia has been often found in patients without diabetes, which is more concerning in clinical practice. Stress hyperglycemia may be induced by a decrease of both insulin secretion and the worsening of insulin resistance (8) , it may produce organ damage by inducing endothelial dysfunction and thrombosis through the glycation process and oxidative stress generation (8) . Evidences have showed that critical COVID-19 cases exhibit characteristics of severely impaired immune system, systemic inflammatory reactions and cytokine storm. Our study indicated that admission FBG level was positively correlated with inflammatory biomarkers, such as WBC and neutrophil and negatively correlated with immune state biomarker-lymphocyte.

In conclusion, this present study demonstrated that a high level of admission FBG was an independent risk factor for developing critical illness of COVID-19 patients. Admission FBG was associated with systemic inflammatory reactions and immune state. As a convenient and easy-to-detect marker, blood glucose level can be obtained and monitored in clinical settings.

Continuous glucose monitoring is particularly necessary in COVID-19 patients with elevated admission FBG. Glucose control helps prevent and control infections and their complications (9) . Therefore, well-controlled blood glucose may lead to an improved outcomes of patients with COVID-19.

The authors declare no competing interests. 

Serum ferritin as an independent risk factor for severity in COVID-19 patients

Risk factors of critical & mortal COVID-19 cases: A systematic literature review and meta-analysis

Guidelines for the diagnosis and treatment of novel coronavirus (2019-nCoV) infection (trial version 7) (in Chinese). National Health Commission of the People's Republic of China

Diagnosis and Treatment of Adults with Community-acquired Pneumonia. An Official Clinical Practice Guideline of the

Obesity as a Potential Predictor of Disease Severity in Young COVID-19 Patients: A Retrospective Study

Admission hyperglycemia and radiological findings of SARS-CoV2 in patients with and without diabetes

Elevation of blood glucose level predicts worse outcomes in hospitalized patients with COVID-19: a retrospective cohort study

Why is hyperglycaemia worsening COVID-19 and its prognosis?

Association of Blood Glucose Control and Outcomes in Patients with COVID-19 and Pre-existing Type 2 Diabetes