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

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.