Glycated haemoglobin (HbA1c) levels among 3,295 hospitalised COVID-19 patients with and without diabetes and risk of severe infection, admission to an intensive care unit, and all-cause mortality

AIMS Diabetes and hyperglycaemia have been associated with a more severe disease course in COVID-19 patients. However, less is known regarding the risk of adverse outcomes across the spectrum of glycated haemoglobin(HbA1c) levels among COVID-19 patients with and without diabetes. MATERIALS AND METHODS Danish nationwide registries were used to study the association between HbA1c levels and 30-day risk of all-cause mortality and the composite of severe COVID-19 infection, intensive care unit(ICU)admission, or all-cause mortality. The study population comprised patients hospitalised with COVID-19(3rd March-31st December 2020)with a positive PCR-test and an available HbA1c≤6 months before the first positive PCR-test. All patients had at least 30 days of follow-up. Among patients with diabetes,HbA1c was categorised as 64mmol/mol. Among patients without diabetes,HbA1c was stratified into 64mmol/mol(15.1%[6.2-24.0%]), compared with HbA1c 59-64mmol/mol(reference). Among patients without diabetes, the standardised absolute risk difference of the composite outcome was greater with HbA1c 64mmol/mol had a higher associated risk of the composite outcome. Similarly, among patients without diabetes, varying HbA1c levels were associated with higher risk of the composite outcome. This article is protected by copyright. All rights reserved.