P-213: The underside of extended wear infusion sets
J Bjerrekær, A K Berg, M B Christensen, T Suvitaival, K Nørgaard, J SvenssonAbstract
Introduction
Prolonged infusion-set wear time can affect insulin absorption, glycemic outcomes, and morphology of the subcutis.
Objectives
To compare 3-day versus 7-day infusion sets in children and adolescents with type 1 diabetes, focusing on glycemic outcomes, insulin dose, and ultrasound-detected hyperechogenicity as a potential precursor to lipohypertrophy.
Methods
In this randomized crossover study, 63 participants aged 7–17 years used 3-day and 7-day infusion sets for 4 months each with the MiniMed 780G AID system; analyses were per protocol. CGM and insulin outcomes were assessed on final full day of each infusion set wear period. Ultrasound was performed at latest and penultimate infusion-site positions at both study visits. Differences in glycemia and insulin dose were analyzed using adjusted mixed-effects models accounting for repeated measurements within participants, visit, treatment sequence, and insulin type. Hyperechogenicity was analyzed using adjusted Poisson regression with participant-level clustering and reported as relative risk (RR, 95% CI). HbA1c was similar between the two conditions (57 vs 56 mmol/mol; p=0.250). On the final wear day, TIR was similar between the conditions (72% vs 71%; p=0.371), while TITR was slightly lower with the 7-day set (48% vs 50%; p=0.026). TAR (26% vs 27%; p=0.327), TBR (1.8% vs 2.0%; p=0.602), and glucose SD (2.7 vs 2.8 mmol/L; p=0.152) did not differ. Insulin dose was higher with the 7-day set (39 vs 35 U; p<0.001). Hyperechogenicity at the latest site was more frequent with the 7-day set (73% vs 51%; RR 1.44, 95% CI 1.11-1.87; p=0.006), whereas the penultimate site was similar (25% vs 22%; p=0.50).
Conclusions
Compared with 3-day infusion sets, 7-day infusion sets were associated with significant higher insulin requirements, less time in tight range, and more frequent hyperechogenicity at the latest insertion site, while TIR, HbA1c, TAR, TBR, glucose SD, and penultimate-site hyperechogenicity were similar.