The COVID-19 pandemic has infected tens of millions worldwide, including over 5 million in the United States alone, resulting in almost 200,000 U.S. deaths. COVID-19, the new version of the coronavirus causing the pandemic, is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 virus (SARS-CoV-2).
The severity of COVID-19 infection varies widely. Some carriers are asymptomatic and others develop a mild form of the disease. On the other end of the spectrum are those who develop a severe form requiring hospitalization or intensive care unit admission, and even death. It is becoming increasingly clear that certain coexisting conditions, especially diabetes, kidney disease and heart disease greatly increase the risk of more severe short-term and long-term complications. The long-term complications can be severe and will need to be dealt with after a successful vaccine is discovered.
For diabetes, it is now known that:
- Diabetes patients with well versus poorly controlled glycemia (blood sugar) have better prospects during COVID-19 infection.
- Diabetes patients with low versus high glycemic variability have better prospects during COVID-19 infection.
- Diabetes patients with low versus high elevated fasting blood glucose have better prospects during COVID-19 infection.
- Diabetes patients are more prone to COVID-19-induced hyper-inflammatory reactions, which in turn cause hyperglycemia (excessively high blood glucose) and organ damage.
- Common diabetes comorbidities, such as obesity, cardiovascular (heart) disease, chronic kidney disease, hypertension (elevated blood pressure), are also risks for critical COVID-19 infection.
A main avenue of viral entry for COVID-19 is through the nasal passage, specifically the nasal epithelium, which allows the virus to directly invade the central nervous system. This is why a number of patients have reported a loss of taste/smell. They have also suffered from stroke, brain inflammation, delirium, and dementia. Regarding long-term complications, the following has been found:
- COVID-19 can invade nerve tissue in patients, leading to neurological diseases.
- If COVID-19 invades peripheral nerves, it can lead to peripheral neuropathy, autonomic neuropathy, and muscle damage.
- COVID-19-induced neurological damage may be permanent.