Predictors of glycaemic improvement in children and young adults with type 1 diabetes and very elevated HbA1c using the MiniMed 780G system

Abstract

Aims: This study aimed to identify key factors with the greatest influence on glycaemic outcomes in young individuals with type 1 diabetes (T1D) and very elevated glycaemia after 3 months of automated insulin delivery (AID).

Materials and methods: Data were combined and analysed from two separate and previously published studies with similar inclusion criteria assessing AID (MiniMed 780G) efficacy among young individuals naïve to AID (aged 7-25 years) with glycated haemoglobin A1c (HbA1c) ≥69 mmol/mol (≥8.5%). Univariate and multivariate linear models were performed to explore factors leading to the greatest improvements in HbA1c and time in range 3.9-10.0 mmol/L (70-180 mg/dL; TIR).

Results: A total of 99 young individuals (aged 17.3 ± 4.2 years; baseline HbA1c 92 ± 21 mmol/mol [10.6% ± 1.9%]) were included. After 3 months of AID use, HbA1c improved to 65 ± 16 mmol/mol (8.1% ± 1.5%) (-27 ± 23 mmol/mol; -2.5% ± 2.1% change), and TIR improved from 24.2% ± 13.5% to 58.4% ± 15.4% (p both <0.001). In the multivariate analysis, two key factors for both HbA1c and TIR improvement were identified: high baseline HbA1c (>100 mmol/mol [>11.0%]) and high time in automation mode (>80%), which led to decreased HbA1c by 27.0 mmol/mol (2.4%) and 14.2 mmol/mol (1.3%) and increased TIR by 6.1% and 11.1% (p all <0.05) respectively. Meal announcement frequency >3 times/day and glucose target of 5.5 mmol/L (100 mg/dL) also led to significant increases in TIR. No other factors, including age, prior use of multiple daily injection, ethnicity, gender and optimal active insulin time 2 h, contributed to statistically significant HbA1c or TIR improvement.

Conclusions: In young individuals naive to AID, those with the highest baseline HbA1c and high percentage time in automation experience the greatest benefits after initiation of AID. Sociodemographic background and carbohydrate counting adherence/knowledge should not prevent or delay access to AID technology (ACTRN12621000556842 and ACTRN12622001454763).

Keywords: automated insulin delivery; children and adolescents; type 1 diabetes mellitus.

FIGURE 1

Glycaemic outcomes from baseline and after 3 months of automated insulin delivery (AID) use. Data are mean (SD) and represent the 14‐day average of baseline, 12–13 weeks of AID data. CV, coefficient of variation; HbA1c, glycated haemoglobin A1c; SG, sensor glucose; TAR, Time above range; TBR, time below range; TIR, time in range 3.9–10.0 mmol/L (70–180 mg/dL); TITR, Time in tight range 3.9–7.8 mmol/L (70–140 mg/dL).

FIGURE 2

Point range plots showing the estimated mean change in HbA1c, glycated haemoglobin A1c (HbA1c) (in mmol/mol; left panel), and time in range (TIR) 3.9–10.0 mmol/L (70–180 mg/dL; right panel) after 3 months of automated insulin delivery use. Black dots with grey bands represent estimated mean change with 95% confidence intervals. Within each panel, pairwise comparisons of groups were calculated from multivariate analysis after adjusting for all other covariates in the figure.