Type 2 diabetes and COVID-19 related mortality in the critical care setting: A national cohort study in England, March-July 2020

Objective: To describe the relationship between type 2 diabetes and all-cause mortality amongst adults with COVID-19 in the critical care setting.

Research Design and Methods: Nationwide retrospective cohort study in people admitted to hospital in England with COVID-19 requiring admission to a high dependency unit (HDU) or intensive care unit (ICU) between March 1, 2020 and July 27, 2020. Cox proportional hazards models were used to estimate 30 day in-hospital all-cause mortality associated with type 2 diabetes, adjusted for age, sex, ethnicity, obesity, and other major comorbidities (chronic respiratory disease, asthma, chronic heart disease, hypertension, immunosuppression, chronic neurological disease, chronic renal disease, and chronic liver disease).

Results: 19,256 COVID-19 related HDU and ICU admissions were included in the primary analysis, including 13,809 HDU (mean age 70), and 5,447 ICU admissions (mean age 58). 3,524 (18.3%) had type 2 diabetes. 5,077 people (26.4%) died during the study period. People with type 2 diabetes were at increased risk of death (adjusted hazard ratio (aHR) 1.23 [95%CI 1.14;1.32]), results were consistent in HDU and ICU subsets. The relative mortality risk associated with type 2 diabetes decreased with increasing age (age 18-49 aHR 1.50 [95%CI 1.05;2.15]; age 50-64 1.29 [1.10;1.51]; age 65 or greater 1.18 [1.09;1.29], p-value for age:type 2 diabetes interaction 0.002).

Conclusions: Type 2 diabetes may be an independent prognostic factor for survival in people with severe COVID-19 requiring critical care treatment, and in this setting the risk increase associated with type 2 diabetes is greatest in younger people.