112-OR: Metabolic Outcomes One Year after Total Pancreatectomy with Islet Autotransplantation after Early Pump Initiation

Background: We previously published that insulin pump initiation immediately after IV insulin therapy was associated with improved post-surgical glycemic outcomes compared to multiple daily injections (MDI) in pediatric patients following total pancreatectomy with islet autotransplantation (TPIAT) . We investigated metabolic outcomes of this population at 1 year post-TPIAT to assess if the improved outcomes in the early pump group were sustained over time.

Methods: We retrospectively reviewed 40 patients post-TPIAT previously studied at days post-surgery (14 used MDI and 26 used pump therapy immediately post-ICU, all discharged on pump therapy) . Data analyzed included: demographics, islet equivalents per kilogram (IEQ/kg) transplanted, exogenous insulin use, and baseline vs. 1 year (via mixed meal testing) HgA1C, fasting glucose, insulinogenic index and area under the curve (AUC) for insulin and c-peptide.

Results: More patients were off insulin at 1 year in the early pump group compared to the MDI group (43% vs. 14%, p=0.08) . Of all patients off insulin, 100% of the early pump users weaned off by 6 months post-TPIAT compared to 30% of the MDI users. Two known variables associated with favorable insulin outcomes, lower age and higher IEQ/kg were not significantly different between groups. Fasting glucose was lower in the early pump group compared to the MDI group (median 97.5 vs. 122 mg/dL, p=0.01) while AUC c-peptide was greater in early pump users at 1 year post-TPIAT but did not reach significance (median 65.3 vs. 49.5 ng/mL x minutes, p=0.07) . Other metabolic outcomes did not differ between groups.

Conclusion: Despite lower median age and higher IEQ/kg in the MDI group, the early pump group had a lower fasting glucose. Though not significant, the early pump group had a higher proportion off insulin and greater AUC c-peptide secretion. This study was limited by sample size. Early pump use may have long term benefits in post-TPIAT endogenous insulin secretion.