Excess diabetes-related deaths: the role of comorbidities through different phases of the COVID-19 pandemic

BACKGROUND AND AIMS: Diabetes confers an excess risk of death to COVID-19 patients. Causes of death are now available for different phases of the pandemic, encompassing different viral variants and COVID-19 vaccination. The aims of the present study were to update multiple causes of death (MCOD) data on diabetes-related mortality during the pandemic and to estimate the impact of common diabetic comorbidities on excess mortality. METHODS AND RESULTS: Diabetes-related deaths in 2020-2021 were compared with the 2018-2019 average; furthermore, age-standardized rates observed during the pandemic were compared with expected figures obtained from the 2008-2019 time series through Generalized Estimating Equation (GEE) models. Changes in diabetes mortality associated with specific comorbidities were also computed. Excess diabetes-related mortality was +26% in 2020 and +18% in 2021, after the initiation of the vaccination campaign. The presence of diabetes and hypertensive diseases was associated with the highest mortality increase especially in subjects aged 40-79 years, +41% in 2020 and +30% in 2021. CONCLUSION: The increase in diabetes-related deaths exceeded that observed for all-cause mortality and the risk was higher when diabetes was associated with hypertensive diseases. Notably, the excess mortality decreased in 2021, after the implementation of vaccination against COVID-19.