Endocrine Abstracts

Introduction: Several formulas are described to calculate the Insulin Dose to start insulin pump therapy. However, there are no data demonstrating their effectiveness in achieving good glycemic control.

Aim: To assess the Total Daily Dose of Insulin (TDDI) at 3 months after beginning an insulin pump, and determine which formula most closely matches the TDDI required in cases where good glycemic control is achieved after that period.

Methods: Retrospective study including individuals with type 1 diabetes who started treatment with an insulin pump between 1^stof January of 2019 and 30^thof September of 2021 at our center. Patients were frequently evaluated until glycemic control was achieved. Glycemic control was assessed at ‘time zero’(T0) and ‘time 3 M’(T3 M) through the HbA1c value, % time in target range(%TIR), % time above(%TAR) and below the target range(%TBR). The TDDI at T3 M months was compared with the insulin dose calculated by the different formulas at T0: F1-mean TDDI of the 7 days preceding the beginning of treatment;F2-TDDI calculated by weight(0.5xweight);F3-obtained by 90% of the mean of F1 and F2 ([F1+F2]/2x0.9).

Results: Of the 62 individuals who started treatment, 52 were included(30[57.7%] women; median age 39 years [minimum-maximum:19–70 years]), with a mean of 22±13.28 years of disease progression. At T3 M, the median %TIR was 63.5%(IQR 24%), the median %TAR 32%(IQR 31), the median %TBR 3%(IQR 6) and the median HbA1c 7.1%(IQR 1.3). The median TDDI at T3 M was 42 UI (IQR 21.5UI) and was similar to TDDI at T0 by F1(40.5UI[IQR 19.2], P=0.723) but with a significantly lower percentage of basal insulin(38%vs.49.3%, P<0.001). The median TDDI at T3 M was significantly superior than TDDI obtained by F2(42UI[IQR 21.5UI]vs.32.5UI[IQR 12.3], P<0.001) and by F3(34.1UI[IQR 13.3], P<0.001). In the 19 patients with %TIR >70% at T3 M, the median TDDI at T3 M was not different from the TDDI at T0 calculated by F1(P=0.268) and F2(P=0.427), but major differences were found comparing with F3(37.0UI[IQR 23.8]vs.29.4[IQR 12.2], P=0.05).

Conclusion: The TDDI in use 3 months after the beginning of an insulin pump in this work was quite similar to the mean TDDI of the 7 days preceding the starting of this treatment. This result was similar in patients with TIR above or below 70% at T3 M. The main difference at T3 M was the percentage of basal insulin which decrease significantly from almost 50% to 40%. These results suggest that the mean TDDI of the 7 days preceding the starting of this treatment can be the best option to begin the insulin pump.