Guo et al. indicate diabetes increases the severity and mortality rate of COVID-19, which is similar to the outcomes seen with the SARS and H1N1 epidemics (1). Given that diabetes is highly prevalent and SARS-CoV-2 highly transmissible, diabetes may significantly increase the COVID-19 disease burden.
Diabetics, as well as those with obesity and other metabolic disorders, present with chronic low-grade inflammation, as evidenced by elevated levels of IL-6, fibrinogen, C-reactive protein, and D-dimer. These changes increase risk of the cytokine storm that is the direct cause of death in many COVID-19 patients. Many of the drugs being tested to treat or prevent COVID-19 mortality — including tocilizumab, siltuximab, and others like them — suppress IL-6 activity, emphasizing the significance of the elevated levels seen in diabetics.
The relationship between COVID-19 and diabetes may be bidirectional. The SARS-CoV-2 virus enters cells via ACE2 present in both liver and pancreas cells (2). Viral infection of these cells impairs insulin secretion and glycemic control, thereby worsening the inflammatory state associated with diabetes.
The editorial authors conclude there are closer and more substantial links between diabetes and COVID-19 than are initially apparent.
- Clinical features and short‐term outcomes of 144 patients with SARS in the greater Toronto area; Diabetes and the severity of pandemic influenza a (H1N1) infection
- Receptor recognition by novel coronavirus from Wuhan: An analysis based on decade‐long structural studies of SARS; The sweeter side of ACE2: physiological evidence for a role in diabetes