Severe Covid-19 infection in type 1 and type 2 diabetes mellitus during the first three waves in Sweden

Objective Type 2 diabetes is an established risk factor for hospitalization and death in COVID-19 infection while findings with respect to type 1 diabetes have been diverging. 

Research Design and Methods Using nationwide health registries, we identified all patients aged ≥18 years with type 1 and type 2 diabetes in Sweden. Odds ratios (ORs) describe general- and age specific risk of being hospitalized, in need of intensive care, or dying, adjusted for age, socioeconomic factors and coexisting conditions, compared to individuals without diabetes. Machine learning models were used to find predictors of outcomes among COVID-19-positive individuals with diabetes. 

Results Until June 30, 2021, we identified 365 (0.71%) and 11,684 (2.31%) hospitalizations in 51,402 and 504,337 patients with type 1 and 2 diabetes, respectively, with 67 (0.13%) and 2,848 (0.56%) cases requiring ICU care, while there were 68 (0.13%) and 4,020 (0.80%) deaths, which we compared with 7,824,181 individuals without diabetes (41,810 hospitalizations (0.53%), 8,753 (0.11%) needing ICU care, and 10,160 (0.13%) deaths). Although those with type 1 diabetes had moderately raised odds of being hospitalized, multiple-adjusted OR 1.38(95% CI 1.24-1.53), there was no independent effect on ICU care or death (ORs of 1.21(95% CI 0.94-1.52) and 1.13(95% CI 0.88-1.48)). Age and socioeconomic factors were the dominating features for predicting hospitalization and death in both types of diabetes. 

Conclusions Type 2 diabetes were associated with increased odds for all of the outcomes, whereas patients with type 1 diabetes had moderately increased odds of hospitalization but not ICU care and death.