Effects of Two COVID-19 Lockdowns on HbA1c Levels in Patients with Type 1 Diabetes and Associations with Digital Treatment, Health Literacy, and Diabetes Self-Management: A Multicenter, Observational Cohort Study Over 3 Years

Short-term studies reported improved glycemic control and a decrease in eHbA1c (estimated hemoglobin A1c) in patients with type 1 diabetes during COVID-19 lockdown, but long-term changes are unknown. Therefore, the main objectives are to (1) analyze whether laboratory-measured HbA1c changed during and after two lockdowns and (2) investigate potential variables influencing HbA1c change. In this cohort study, 291 adults with type 1 diabetes were followed over 3 years including the prepandemic phase and two lockdowns. The data from medical records and validated questionnaires assessing health literacy (HLS-EU-Q16), diabetes self-management (DSMQ-R27), general self-efficacy (GSE), and social support (F-SOZU-K14) were used to analyze associations with HbA1c levels (N = 2370) by performing multivariable linear regressions. The median age was 54 (38–63) years and 159 (54.6