Elevated fasting blood glucose within the first week of hospitalization was associated with progression to severe illness of COVID-19 in patients with preexisting diabetes: A multicenter observational study.

Highlights Fasting blood glucose < 10 mmol/L was proposed as a target of glycemic control during the first week of hospitalization in patients with preexisting diabetes. Poor HbA1c levels prior to coronavirus disease 2019 (COVID-19) might not be associated with severity among patients with preexisting diabetes. Mean blood glucose seemed not to be associated with poor prognosis of COVID-19.