Covid-19 may trigger the onset of diabetes in healthy people, and also cause severe complications in diabetic patients, according to an international group of 17 leading experts in the chronic condition.Based on clinical observations made so far, the scientists, including Stephanie A. Amiel from King’s College London in the UK, said there is a bi-directional relationship between Covid-19 and diabetes.

In a letter published in the New England Journal of Medicine, they explained that diabetes, on the one hand, is associated with increased risk of Covid-19 severity and mortality with 20 to 30 per cent of patients who died with the infectious disease reported to have diabetes. On the other hand, the researchers said new-onset diabetes and atypical metabolic complications of pre-existing diabetes -- including life-threatening ones -- have been observed in people with Covid-19.

However, they said it is still unclear how SARS-Cov-2, the virus that causes Covid-19, impacts diabetes. Earlier studies had shown that the protein ACE-2 which binds to SARS-Cov-2 and allows the virus to enter human cells is not only located in the lungs, but also in organs and tissues involved in glucose metabolism such as the pancreas, the small intestine, the fat tissue, the liver and the kidney.

According to the researchers, by entering these tissues, the virus may cause multiple and complex dysfunctions of glucose metabolism. The scientists believe it is possible that the novel coronavirus may alter glucose metabolism that could complicate the condition of pre existing diabetes or lead to new mechanisms of disease.

Based on previous research, they said virus infections can also precipitate type 1 diabetes - a chronic condition in which the pancreas produces little or no insulin.

“Diabetes is one of the most prevalent chronic diseases and we are now realising the consequences of the inevitable clash between two pandemics,” said Francesco Rubino, Professor of Metabolic Surgery at King’s College London. However, given the short period of human contact with this new coronavirus, the exact mechanism by which the virus influences glucose metabolism is still unclear, the scientists said.

“We don’t know whether the acute manifestation of diabetes in these patients represent classic type 1, type 2 or possibly a new form of diabetes,” Rubino added. “We don’t yet know the magnitude of the new onset diabetes in Covid-19 and if it will persist or resolve after the infection, and if so, whether or not or Covid-19 increases risk of future diabetes,” said Paul Zimmet, Professor of Diabetes at Monash University in Melbourne.

According to the researchers, assessing routinely collected clinical data can help examine insulin secretory capacity, insulin resistance, and autoimmune antibody status to understand how Covid-19 related diabetes develops, its natural history, and best management. “We are calling on the international medical community to rapidly share relevant clinical observations that can help answer these questions,” Zimmet said.