LAUSR

Ultrarapid insulins (Lyumjev, Fiasp) are designed to reduce post-prandial excursions and may be beneficial in automated pumps. There is no published data on ultrarapid insulins in the OP5 system. We evaluated glycemic and behavioral measures after switching to ultrarapid insulin. Data was reviewed retrospectively from people with T1D on OP5 with minimum 3 months rapid insulin prior to switching to ultrarapid. Glycemic measures included A1c, TIR, TBR, TAR, SD, CoV. Surrogates for bolus behavior were override frequency and boluses/day. Linear mixed models were used. Qualitative reports from clinical documents were reviewed. Of 40 youth and young adults (mean age 12.6 yrs, 46% female, mean T1D duration 5.4 yrs, mean A1c 7.0±0.2%), 13 were using Fiasp and 27 were using Lyumjev. No statistical significances were seen in TIR, TBR, TAR, SD, CoV, A1c, and boluses/day. GMI was higher with Lyumjev and overall. Override frequency was less in Lyumjev and overall. Review of 15 clinical reports showed positive experiences after switching, with less perceived postprandial excursions. Clinically significant glycemic differences were not seen with ultrarapid insulin with OP5, suggesting that these insulins are interchangeable in an automated system. However, satisfaction and bolus overrides improved with ultrarapid insulin. A larger sample size and meal-specific measures are needed to connect patient experience with glycemic outcomes. M. Maher: None. C. Sakamoto: None. E.C. Cobry: Advisory Panel; Dexcom, Inc. Other Relationship; Dexcom, Inc.