In a recent study published in Communications Biology, a team of scientists investigated how type 2 diabetes and genetic susceptibility to the disease impacted the severity of and mortality risk associated with coronavirus disease 2019 (COVID-19) using data from the United Kingdom (U.K.) Biobank.

Despite widespread vaccination across the globe, the COVID-19 pandemic continues, albeit in a less virulent form, with new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 infections have been found to manifest in a wide range of symptoms, from asymptomatic to severe cases involving acute respiratory distress, pneumonia, and death. A significant number of COVID-19 cases are also known to progress into post-acute COVID-19 syndrome, commonly known as long coronavirus disease (long COVID). Extensive research also indicates that clinical factors such as age, smoking behavior, and the presence of comorbidities such as type 2 diabetes, obesity, cardiovascular disease, hypertension, and respiratory diseases are risk factors for severe COVID-19. Genome-wide association studies have also shown that genetic variants linked to increased risk of cardiovascular disease, type 2 diabetes, lung disease, and those involved in immune mechanisms are associated with a higher risk of severe SARS-CoV-2 infections.

In the present study, the scientists used U.K. Biobank data to investigate whether type 2 diabetes and polygenic risk scores for type 2 diabetes were associated with increased severity of SARS-CoV-2 infections and a higher COVID-19 mortality rate. Additionally, they examined the effect of vaccinations on this association and evaluated the impact of numerous SARS-CoV-2 variants, including the recently emerged Omicron variants. The polygenic risk scores for type 2 diabetes from the genome-wide association study summary statistics obtained from the U.K. Biobank were first used to determine the genetic predisposition for type 2 diabetes. Here, to account for the confounding impact of body mass index (BMI) on type 2 diabetes, the researchers included BMI as a covariate while calculating the type 2 diabetes polygenic risk scores in the genome-wide association study. Subsequently, they used the proportional odds models to determine whether type 2 diabetes and the genetic predisposition to type 2 diabetes were associated with increased severity and mortality of COVID-19. The findings of this study shed light on the significant impact of type 2 diabetes and genetic susceptibility to the disease on COVID-19 outcomes, emphasizing the importance of understanding the interplay between comorbidities, genetic factors, and viral infections.