Characteristics associated with having a hemoglobin A1c ≤ 7 % (≤53 mmol/mol) among adults with type 1 diabetes using an automated insulin delivery system.

Background: We aim to investigate which characteristics are associated with having an HbA1c ≤ 7 % (≤53 mmol/mol) among adult automated insulin delivery (AID) users living with type 1 diabetes (T1D).

Methods: Cross-sectional study using data from the T1D BETTER registry.

Inclusion Criteria: aged ≥ 18 years old, using a commercial AID system, and with a reported HbA1c range value. Participants were divided into two groups (HbA1c ≤ 7 % group, N = 57; and HbA1c > 7 % group, N = 74).

Results: A total of 131 participants were included: 61.8 % females, median age (Q1-Q3) was 43.0 (30.0, 55.0) years, and median duration of T1D was 24.0 (16.0, 36.0) years. Logistic regression analysis suggested that participants with a bachelor's degree or above were more likely (OR 3.04, 95 %CI 1.22, 7.58; P = 0.017) and with a longer duration of pump use were less likely (OR 0.90, 95 %CI 0.84, 0.98; P = 0.009) to report an HbA1c ≤ 7 % when using an AID, after adjusting for age, sex, body mass index, and annual household income.

Conclusions: Our study indicates that among AID users, in order to maximize benefits, additional support is needed for those who do not have a bachelor's degree and/or who have been using an insulin pump for a long time.