Ann Thannickal

COVID-19 is continuing to spread worldwide. More than 510 million confirmed cases and more than 6 million deaths occur across almost 200 countries. The pandemic has played a pivotal role in changing the health landscape by challenging chronic disease management. COVID-19 impact was profound on chronic diseases. Researchers are learning how the virus affects people with chronic disease conditions. One of the most common disease conditions is diabetes.

Does COVID-19 accelerate diabetic symptoms?

People with diabetes face a higher chance of experiencing severe complications from COVID-19. People with diabetes are more likely to experience severe symptoms and complications when infected with a virus. When people with diabetes do not manage their diabetes well and experience fluctuating blood sugars, they are generally at risk for several diabetes-related complications. Having heart diseases or other difficulties, in addition to diabetes, could worsen your chance of getting seriously ill from COVID-19, like other viral infections, because your body’s ability to fight off an infection is compromised. Viral infections can also increase inflammation or internal swelling in people with diabetes. Higher blood sugars also cause this, contributing to more severe complications.

Everyone needs to be careful to avoid the coronavirus that causes COVID-19. If you have type 1 or type 2 diabetes, your risk of catching the virus is not higher than anyone else; but you could have worse complications if you do get sick. Studies have shown that about 25% of people who went to hospitals with severe COVID-19 infections had diabetes. Those with diabetes were more likely to have severe complications and die from the virus. Your risk of severe coronavirus infection is even higher, if you also have another condition, like heart or lung disease. One reason is that high blood sugar weakens the immune system and makes it less able to fight off infections.

How does COVID-19 trigger diabetes?

Emerging evidence suggests that COVID-19 may trigger the onset of diabetes in healthy people. It is still unclear how SARS-Cov-2, the virus that causes COVID-19, impacts diabetes. Studies show that ACE-2 (angiotensin-converting enzyme 2), the protein that binds to SARS-Cov-2, is located in the lungs, organs and tissues involved in glucose metabolism such as the pancreas, the small intestine, the fat tissue, the liver, and the kidneys. The virus may cause multiple and complex dysfunctions of glucose metabolism by entering these tissues.

There is a bidirectional relationship between Covid-19 and diabetes. On the one hand, diabetes is associated with an increased risk of severe Covid-19. On the other hand, new-onset diabetes and severe metabolic complications of preexisting diabetes have been observed in patients with Covid-19. These manifestations of diabetes pose challenges in clinical management and suggest complex pathophysiology of Covid-19–related diabetes.

To address these issues, an international group of leading diabetes researchers participating in the CoviDIAB Project has established a global registry of patients with Covid-19-related diabetes. The goal of the registry is to show the extent and phenotype of new-onset diabetes that is defined by hyperglycemia, confirmed Covid-19, negative history of diabetes, and a history of a normal glycated hemoglobin level. Given the very short history of human infection with SARS-CoV-2, an understanding of how Covid-19–related diabetes develops, the natural history of this disease, and appropriate management will be helpful. The study of Covid-19–related diabetes may also uncover novel mechanisms of disease.

Reference
Yan Xie, Ziyad Al-Aly. Risks and burdens of incident diabetes in long COVID: a cohort study.
Lancet Diabetes and Endocrinology, Vol.10: 311-321, 2022.