SARS-CoV-2 and COVID-19 in diabetes mellitus. Population-based study on ascertained infections, hospital admissions and mortality in an Italian region with ∼5 million inhabitants and ∼250,000 diabetic people

Background and aims: Diabetes conveys an increased risk of infectious diseases and related mortality. We investigated risk of ascertained SARS-CoV-2 infection in diabetes subjects from the Veneto Region, Northeastern Italy, as well as the risk of being admitted to hospital or intensive care unit (ICU), or mortality for COVID-19.

Methods and results: Diabetic subjects were identified by linkage of multiple health archives. The rest of the population served as reference. Information on ascertained infection by SARS-CoV-2, admission to hospital, admission to ICU and mortality in the period from February 21 to July 31, 2020 were retrieved from the regional registry of COVID-19. Subjects with ascertained diabetes were 269,830 (55.2% men; median age 72 years). Reference subjects were 4,681,239 (men 48.6%, median age 46 years). Ratios of age- and gender-standardized rates (RR) [95% CI] for ascertained infection, admission to hospital, admission to ICU and disease-related death in diabetic subjects were 1.31 [1.19-1.45], 2.11 [1.83-2.44], 2.45 [1.96-3.07], 1.87 [1.68-2.09], all p < 0.001. The highest RR of ascertained infection was observed in diabetic men aged 20-39 years: 1.90 [1.04-3.21]. The highest RR of ICU admission and death were observed in diabetic men aged 40-59 years: 3.47 [2.00-5.70] and 5.54 [2.23-12.1], respectively.

Conclusions: These data, observed in a large population of ∼5 million people of whom ∼250,000 with diabetes, show that diabetes not only conveys a poorer outcome in COVID-19 but also confers an increased risk of ascertained infection from SARS-CoV-2. Men of young or mature age have the highest relative risks.