Defining Targets for Continuous Glucose Monitoring After Total Pancreatectomy With Islet Autotransplantation

Abstract

Introduction: Targets for continuous glucose monitoring (CGM) are well established for type 1 and type 2 diabetes. In total pancreatectomy with islet autotransplantation (TPIAT), stricter glycemic targets are needed to avoid metabolic stress on transplanted islets, but no guidelines exist for CGM targets.

Methods: We aimed to determine CGM targets for TPIAT clinical management by associating CGM metrics with goal hemoglobin A1c (HbA1c) ≤ 6.5%. Targets for time in range (TIR) 70-140, TIR 70-180, mean CGM glucose, and time in hyperglycemia (>140, >180, >250 mg/dL) were chosen to give good sensitivity and specificity for identifying HbA1c ≤6.5%.

Results: We included 256 pairs of 14-day CGM metrics with a concurrent HbA1c value (n = 82 patients, age 35 [IQR 19-46] years at surgery, 70% female) who were ≥0.5 years post TPIAT (median 4.1 years) and wearing Dexcom G6. Most patients had more than one HbA1c and corresponding CGM available (median 2 [IQR 1-4] per patient).

Conclusion: We found that TIR 70-140 ≥ 50% and TIR 70-180 mg/dL ≥ 75% may be reasonable minimum targets for patients and providers using CGM data to manage diabetes long-term after TPIAT. Failure to meet these targets should prompt starting or adjusting insulin therapy, especially if hypoglycemia is not a concern.

Keywords: autologous; blood glucose; clinical targets; continuous glucose monitoring (CGM); diabetes; glycated hemoglobin; pancreatectomy; total pancreatectomy with islet autotransplantation (TPIAT); transplantation.