Dear editor,

Cases of newly diagnosed diabetes have been observed in people with the novel coronavirus disease (COVID-19), often with severe hyperglycaemia and diabetic keto-acidosis. An international group of leading diabetes researchers participating in the CoviDIAB Project calls for a global registry of patients with Covid-19–related diabetes (covidiab.e-dendrite.com) ¹. It is indeed difficult to determine whether these are exacerbations of existing diabetes or new-onset diabetes. The glycohaemoglobin A1c test indicates a patient’s average blood sugar levels for the past two to three months. If the newly diagnosed diabetes is indeed of recent onset, the test values should be relatively low. In addition, performing the test every month thereafter and comparing the results with the initial results may provide a clue to the timing of diabetes onset. Therefore, COVID-19 patients should have their glycohaemoglobin A1c measured on admission, and if necessary, every month thereafter.

Rubino F, Amiel SA, Zimmet P, et al. New-Onset Diabetes in Covid-19 [published online ahead of print, 2020 Jun 12]. N Engl J Med . 2020;NEJMc2018688. doi:10.1056/NEJMc2018688