Treatment Modality-Dependent Risk of Diabetic Ketoacidosis in Patients with Type 1 Diabetes: Danish Adult Diabetes Database Study

Background and Aims: The aim of this study was to evaluate the incidence rates of diabetic ketoacidosis (DKA) according to treatment modality in patients with type 1 diabetes (T1D) in Denmark, either multiple daily injections (MDI) or continuous subcutaneous insulin infusion (CSII). Materials and Methods: A total of 20,902 T1D registered in the Danish Adult Diabetes Database were followed for an average of 5.4 years. Poisson regression analyses with risk time as offset were used to compare differences in rates of DKA between CSII and MDI. Model was adjusted for age, sex, diabetes duration, previous DKA events, and hemoglobin A(1c) (HbA(1c)). A modifying effect of number of CSII patients on the DKA rates was tested. Results: During 113,731 person-years, 3100 DKA events were registered (53 among CSII). CSII patients were younger (42.3 vs. 47.9 years), a larger proportion was female (59% vs. 43%), had a shorter diabetes duration (19 vs. 21 years), and a lower HbA(1c) (61.9 vs. 66.6mmol/mol). There was no significant difference in the incidence rate of DKA between CSII and MDI (rate ratio: 1.30, 95% confidence interval: 0.97-1.76). However, in clinics with at least 250 CSII patients, rates of DKA events were lower among CSII users, while the opposite was true for the smaller clinics (P=0.016). Conclusions: Delivery of CSII in large diabetes clinics with sufficient support and patient education may ensure that CSII treatment does not lead to an increased risk of DKA.