ESPE Abstracts

Introduction: With the development and use of automated insulin delivery (AID) technologies like Advanced Hybrid Closed Loop (AHCL or Minimed 780G) system, it becomes possible to achieve tighter glycemic control. A new parameter called “Time in Tight Range” (TITR, 70-140 mg/dL) has been proposed to evaluate glycemic control in the latest consensus on the use of continuous glucose monitoring (CGM) data in diabetes research. This study aims to assess the effect of the AHCL system use on TITR.

Methods: 2128-day CGM and pump reports of 56 children who used AID-AHCL and had at least 14 days of sensor data available between January 2021 and March 2023 were evaluated retrospectively. The CGM data were analyzed in terms of the rates of TIR >70% and >80% and TITR >50% and >60%. The glycemic parameters were evaluated separately as nighttime (00.00-06.00) and daytime (06.00-00.00).

Results: Of the participants, 59% were female, the mean age was 12.2±3.5 years, the mean duration of diabetes was 5.5±5 years, and the mean duration of AHCL use was 0.9±0.56 years. Both mean TIR and mean TITR were significantly higher at nighttime than at daytime (87.5±8.4% vs 78.8±8% & 68.2±13.4 vs 57.5±8.7% p1 <0.001, p2 <0.001). TITR had a strong positive correlation with TIR (r: 0.902, P<0.001) and a negative correlation with HbA1c (r: -0.755, p: <0.001). The rates of TIR >70% and >80% were 93% and 52%, respectively, while the rates of TITR >50% and >60% were 87% and 52%, respectively. The cut-off level for TITR in estimating an HbA1c value of <6.5% was determined to be 62%, with a sensitivity of 80% and specificity of 81%. There was no statistically significant difference between those with and without the rate of TITR >60% in terms of hypoglycemia (TBR <70mg/dl and TBR <54mg/dl; p1:0.084, p2:0.298). Those with autocorrection rate >30% had higher basal insulin percentage (41.2±3.8% vs 35±5.5%, P<0.001) and lower TIR and TITR (75.6±8.6% vs 82.6±6.1% & 53.8±7.5% vs 62.1±7.5%; p1: 0.008, p2: 0.002).

Conclusion: It is possible to meet the CGM consensus targets and recommended TITR target, as a tighter glycemic control parameter, without an increase in the hypoglycemia rate with the use of AID. A target of >50% for TITR seems realistic. Having better TIR and TITR values during nighttime and in those with an autocorrection rate <30% indicates the effect of postprandial hyperglycemia in diabetes management.