AbstractWhen the corona pandemic commenced more than two years ago, it was quickly
recognized that people with metabolic diseases show an augmented risk of severe
COVID-19 and an increased mortality compared to people without these
comorbidities. Furthermore, an infection with SARS-CoV-2 has been shown to lead
to an aggravation of metabolic diseases and in single cases to new-onset
metabolic disorders. In addition to the increased risk for people with diabetes
in the acute phase of COVID-19, this patient group also seems to be more often
affected by long-COVID and to experience more long-term consequences than people
without diabetes. The mechanisms behind these discrepancies between people with
and without diabetes in relation to COVID-19 are not completely understood yet
and will require further research and follow-up studies during the following
years. In the current review, we discuss why patients with diabetes have this
higher risk of developing severe COVID-19 symptoms not only in the acute phase
of the disease but also in relation to long-COVID, vaccine breakthrough
infections and re-infections. Furthermore, we discuss the effects of lockdown on
glycemic control.