Letter to the Editor

Abstract

Continuous glucose monitoring (CGM) measures interstitial glucose levels up to 1440 times per day, providing vastly more information to guide insulin dosing than fingerstick blood glucose levels. Another technological improvement has been the availability of algorithm-driven insulin pumps, which can now automatically deliver insulin to correct high-glucose levels and suspend insulin delivery to prevent hypoglycaemia. These pumps, known as advanced hybrid closed-loop (AHCL) systems, substantially reduce the need for manual intervention, but still require effort from patients to accurately enter the amount of carbohydrates they are consuming. Furthermore, AHCL systems are complex, requiring detailed education by a multidisciplinary team for successful use.¹ Insulin pumps are not publicly funded in Australia. Data on the long-term clinical impact of CGM and AHCL in real-world paediatric settings are limited.^{2, 3}

We compared 2016–2021 CGM data from our metropolitan paediatric type 1 diabetes clinic to our data from 2021–2024, including the proportion meeting International Consensus guidelines⁴ (see Table 1). We also recorded HbA1c, height, weight, body mass index, clinic attendance and median income of postcode (Australian Taxation Office 2019–2020). We calculated CGM measures using Python (Python Software Foundation, Beaverton, OR, USA) and used SPSS (version 27) (IBM, Armonk, NY, USA) to perform descriptive analysis and to determine the relationship between clinical characteristics and glycaemic outcomes.

Overall, 10% of participants met every consensus target in 2021–2024, compared to 4% in 2016–2021. Rates of achieving specific targets improved modestly from 2016–2021 to 2021–2024 irrespective of diabetes therapy. Of note, the median (interquartile range) CGM usage-time improved from 88% (72–95) in 2016–2021 to 95% (82–97) in 2021–2024 (P < 0.001). Multiple linear regression revealed that CGM usage-time (P < 0.001) and clinic attendance percentage (P = 0.008) were significant predictors of time in range (TIR) for the 2016–2021 cohort (adjusted R² for overall model 0.138). For AHCL users in the 2021–2024 cohort, CGM usage-time remained the most significant predictor of TIR (P < 0.001), followed by median yearly income of postcode (P = 0.030, adjusted R² 0.167). An increase in AU$10k in median income was associated with an absolute increase of 3.7% TIR. Sex, body mass index and pump use did not predict TIR.

The proportion of patients meeting International Consensus criteria has improved in recent years but remains low and further improvements are needed. Consistent use of CGM is clinically important. Children living in suburbs with higher median incomes had higher TIR. Ensuring access to these vital technologies remains a high priority, with an important advocacy role for all those involved in the care of children and adolescents with diabetes.

The study was performed in accordance with the principles of the Declaration of Helsinki, the International Council for Harmonisation of Good Clinical Practice guidelines. All individual data have been de-identified and aggregated. The protocol was approved by the Northern Sydney Local Health District Human Research Ethics Committee (2020/ETH01325). The protocol was designed and completed independently by the investigators, without any input from pharmaceutical or medical diagnostic corporations. All authors contributed to the publication and reviewed the manuscript.