ABSTRACT Aims Limited studies have investigated glucose management around swimming in type 1 diabetes (T1D). This observational study of the Omnipod 5 Automated Insulin Delivery (AID) System assessed glycemic patterns and system operation with AID use during swimming. Materials and Methods A total of seven swimmers (aged 11 ± 2 years, 57% female) with T1D recorded their swims using an activity tracker and completed online surveys after swims. Results Participants reported 124 swims lasting 23–146 min. Median (IQR) starting glucose was 133 (93–178) mg/dL, with a change of −17 (−61 to 7) mg/dL during swims. Carbohydrate intake 2‐h before swims was 20 (0–32) grams. Starting glucose ≥ 181 mg/dL showed the largest glucose decreases −86 (−111 to −25) mg/dL during swims. Activity feature was used in 87% of swims with a starting glucose < 90 mg/dL. Automated Mode was maintained for 98% (95%–100%) of swim time with 58% (24%–70%) of this time in Automated Mode: Limited. Conclusions Swimming with AID was associated with generally modest declines in glucose. The Omnipod 5 System largely preserved automation in water (often via Automated Mode: Limited) without reverting to Manual Mode. Starting glucose dominated glycemic trajectory, with larger declines but low hypoglycemia risk at a higher starting glucose, and smaller changes, but more hypoglycemia at a lower starting glucose. Insulin suspension was not enough to reliably prevent hypoglycemia when starting glucose was < 180 mg/dL, highlighting the need for proactive carbohydrate intake with a lower starting glucose, even with AID.
Zaharieva et al. (Mon,) studied this question.