Metabolic Outcomes in Pediatric Patients One-Year Post-Total Pancreatectomy with Islet Autotransplantation after Early Pump Initiation

Abstract

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 a total pancreatectomy with islet autotransplantation (TPIAT). We investigated metabolic outcomes of this population at one-year post-TPIAT to assess if the improved outcomes in the early pump group were sustained over time. We retrospectively reviewed 40 patients post-TPIAT previously studied at 10-days post-surgery (15 used MDI and 25 used pump therapy immediately post-ICU, and all were discharged on pump therapy). Data analyzed included: demographics, islet equivalents per kilogram (IEQ/kg) transplanted, exogenous insulin use, and baseline vs. one-year (via mixed meal testing) HbA1c, fasting glucose, insulinogenic index, and the area under the curve (AUC) for insulin and c-peptide. More patients were off insulin at one year in the early pump group compared to the MDI group (45% vs. 13%, p = 0.07). Of all patients off insulin, 100% of the early pump users weaned off by six 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 vs. 122 mg/dL, p = 0.003), while AUC c-peptide was greater in early pump users at one-year post-TPIAT but did not reach significance (median 57.0 vs. 50.3 ng/mL × minutes, p = 0.14). Other metabolic outcomes did not differ between groups. Despite lower median age and higher IEQ/kg in the MDI group, the early pump group had a lower fasting glucose. Younger TPIAT age (p = 0.02) and early pump users (p = 0.04) were significantly associated with insulin independence at one year. This study was limited by sample size. Early pump use may have long-term benefits in post-TPIAT endogenous insulin secretion.