Incidence of COVID-19 and Risk of Diabetic Ketoacidosis in New-Onset Type 1 Diabetes

Objectives: With this study, our aim was to quantify the relative risk (RR) of diabetic ketoacidosis at diagnosis of type 1 diabetes during the year 2020 and to assess whether it was associated with the regional incidence of coronavirus disease 2019 (COVID-19) cases and deaths.

Methods: Multicenter cohort study based on data from the German Diabetes Prospective Follow-up Registry. The monthly RR for ketoacidosis in 2020 was estimated from observed and expected rates in 3238 children with new-onset type 1 diabetes. Expected rates were derived from data from 2000 to 2019 by using a multivariable logistic trend regression model. The association between the regional incidence of COVID-19 and the rate of ketoacidosis was investigated by applying a log-binomial mixed-effects model to weekly data with Germany divided into 5 regions.

Results: The observed versus expected frequency of diabetic ketoacidosis was significantly higher from April to September and in December (mean adjusted RRs, 1.48-1.96). During the first half of 2020, each increase in the regional weekly incidence of COVID-19 by 50 cases or 1 death per 100 000 population was associated with an increase in the RR of diabetic ketoacidosis of 1.40 (95% confidence interval, 1.10-1.77; = .006) and 1.23 (1.14-1.32; < .001), respectively. This association was no longer evident during the second half of 2020.

Conclusions: These findings suggest that the local severity of the pandemic rather than health policy measures appear to be the main reason for the increase in diabetic ketoacidosis and thus the delayed use of health care during the pandemic.