Diabetes, COVID‐19, and questions unsolved

Abstract

AbstractRecent evidence suggests a role for Diabetes Mellitus in adverse outcomes from COVID‐19 infection; yet the underlying mechanisms are not clear. Moreover, attention has turned to prophylactic vaccination to protect the population from COVID‐19‐related illness and mortality. We performed a comprehensive peer‐reviewed literature search on an array of key terms concerning diabetes and COVID‐19 seeking to address the following questions: 1. What role does diabetes play as an accelerator for adverse outcomes in COVID‐19?; 2. What mechanisms underlie the differences in outcomes seen in people with diabetes?; 3. Are vaccines against COVID‐19 efficacious in people with diabetes? The current literature demonstrates that diabetes is associated with an increased risk of adverse outcomes from COVID‐19 infection, and post‐COVID sequelae. Potential mechanisms include dysregulation of Angiotensin Converting Enzyme 2, Furin, CD147, and impaired immune cell responses. Hyperglycaemia is a key exacerbator of these mechanisms. Limited studies are available on COVID‐19 vaccination in people with diabetes; however, the current literature suggests that vaccination is protective against adverse outcomes for this population. In summary, people with diabetes are a high‐risk group that should be prioritised in vaccination efforts. Glycaemic optimisation is paramount to protecting this group from COVID‐19‐associated risk. Unsolved questions remain as to the molecular mechanisms underlying the adverse outcomes seen in people with diabetes; the functional impact of post‐COVID symptoms on people with diabetes, their persistence, and management; how long‐term vaccine efficacy is affected by diabetes, and the antibody levels that confer protection from adverse outcomes in COVID‐19.