Diabetes is one of the top ten causes of death in Hong Kong. In addition to maintaining a healthy diet, patients with diabetes should stay extra vigilant over the COVID-19 pandemic, according to researchers from the School of Biomedical Sciences of the Faculty of Medicine at The Chinese University of Hong Kong (CU Medicine). An advanced statistical approach was used to find that diabetes may be a risk factor leading to increased susceptibility to or severity of COVID-19 infection through changes in ACE2 expression. The research findings have raised the alarm about the danger faced by diabetes patients, and set a new direction for drug development.

In Hong Kong, a substantial proportion of COVID-19 death cases were diabetes patients. As diabetes is a chronic disease, understanding its pathophysiology and mechanisms are vitally important to protect high-risk groups and identify effective treatments. Dr. Hon Cheong So, Assistant Professor of the School of Biomedical Sciences at CU Medicine, together with Ms Alexandria Lau, student of the Bachelor of Science in Biomedical Sciences Programme, and research fellow Dr. Shitao Rao applied an advanced statistical approach named “Mendelian Randomisation” to analyse relevant risk factors associated to COVID-19.

There is already sound evidence that the higher ACE2 expression, the higher susceptibility to infection by COVID-19 is. The research team made use of “big data” from genome-wide association studies (GWAS) to explore diseases and blood proteins causally linked to altered ACE2 expression in the lung.

After screening over 500 diseases or traits, there is tentative evidence that diabetes-related traits are associated with increased ACE2 expression. The team has observed significant and positive associations with ACE2 expression across multiple diabetes datasets and analytics methods for type 1 and 2 diabetes as well as related traits, including early start of insulin. The findings suggest that patients with diabetes may be more prone to COVID-19 infection or have more severe symptoms than normal people, through changes in ACE2 expression.

As an exploratory analysis, blood proteins linked to altered ACE2 expression were found and examined by the team, which is helpful in elucidating potential molecular mechanisms. The proteins may also serve as potential biomarkers and shed light on drug development or repurposing in the future. Dr. Hon Cheong So remarked, “There is great potential for using genomic big data to uncover risk factors and treatments for COVID-19. One important aspect of this study is that we employ Mendelian Randomisation, which is better at delineating causal relationships than observational studies.” 

The research team emphasises that the present findings are still preliminary but hope this exploratory study can shed light on new research strategies and lead to more confirmatory studies in this area in the future. The study results were recently published in the international scientific journal Diabetes Care. The full research paper can be viewed here.