Researchers conducted a cohort study in which data from people with either type 1 or type 2 diabetes in England was collected from death registrations to analyze potential risk factors for COVID-19-related mortality. It was found that being of male sex and being of older age was linked to a higher risk of COVID-19-related mortality in both type 1 and type 2 diabetic individuals. Preceding hyperglycaemia and impaired renal function were also found to cause a significant increase in risk of COVID-19-related mortality for both type 1 and 2 diabetes. Specifically, for individuals with type 2 diabetes, having an HbA1c of 59 mmol/mol caused a significantly elevated risk for COVID-19-related mortality than those who had HbA1c of 48–53 mmol/mol.