It has been observed that patients with underlying comorbidities, including diabetes, were at higher risk for severe COVID-19 and mortality. A Chinese meta-analysis including 1527 patients showed that patients with diabetes had a 2-fold increase in risk of severe disease or requiring intensive care unit (ICU) admission. 
Diabetes is associated with several macro vascular and micro vascular complications, which finally impact the overall patient’s survival. 
Hyperglycemia and insulin resistance facilitate an increased synthesis of pro-inflammatory cytokines and oxidative stress. This inflammatory process could be the underlying mechanism for the high susceptibility to infection with worse outcome in patients with diabetes. 
Diabetes should be considered as a risk factor for fast progression and bad prognosis of COVID-19, therefore, particular attention should be paid to the treatment of comorbidities. Tight glucose monitoring and careful consideration of drug interactions might reduce worsening of symptoms and adverse outcomes and is, therefore, highly recommended.
- B. Li u. a., „Prevalence and impact of cardiovascular metabolic diseases on COVID-19 in China“, Clin. Res. Cardiol. Off. J. Ger. Card. Soc., März 2020, doi: 10.1007/s00392-020-01626-9.
- R. Williams u. a., „Global and regional estimates and projections of diabetes-related health expenditure: Results from the International Diabetes Federation Diabetes Atlas, 9th edition“, Diabetes Res. Clin. Pract., S. 108072, Feb. 2020, doi: 10.1016/j.diabres.2020.108072.
- S. Knapp, „Diabetes and infection: is there a link?--A mini-review“, Gerontology, Bd. 59, Nr. 2, S. 99–104, 2013, doi: 10.1159/000345107.