Does diabetes increase the risk of COVID-19?
Diabetes appears to be a common comorbidity in patients with COVID-19 although a causal relationship is not clear. For example, a prevalence of diabetes among Chinese cohort, mean age 49.6 years, was reported to be 10.3% which is comparable to the prevalence of diabetes in the general population of China at 10.9% overall and 12.3% among people aged 40-59. 4, 34 Similarly, the prevalence of diabetes among British COVID-19 patients, median age 73 years, of 21% was similar to the reported prevalence of 23.8% among those above the age of 75 years. 35 The US data showed slightly higher prevalence of 33.8% in COVID-19 patients while the prevalence in the general population of a similar age is around 26.8%.36 Therefore, the variable prevalence of diabetes reported in COVID-19 studies may simply reflect the local demographics across different countries. Diabetes may increase the risk of infection due to immunologic defects, such as decreased neutrophilic migration, phagocytosis, intracellular killing, and chemotaxis, however, the evidence remains controversial whether diabetes itself or the associated comorbidities is the main factor involved. 37