The utility of continuous glucose monitoring systems in the management of children with persistent hypoglycaemia

The use of CGM to identify hypoglycemia and glycemic patterns in congenital hyperinsulinism

OBJECTIVES

Unrecognized hypoglycemia, especially in the neonatal population, is a significant cause of morbidity and poor neurologic outcomes. Children with congenital hyperinsulinism (HI) are at risk of hypoglycemia and point of care testing (POCT) is the standard of care. Studies have shown that continuous glucose monitoring (CGM) improves glycemic control and reduces the frequency of hypoglycemia among children with type 1 diabetes. There is limited experience with the use of CGM in children with HI. To assess the glycemic pattern of children with HI on stable therapy and evaluate the frequency of undetected hypoglycemia using Dexcom G6® CGM.

METHODS

A cross-sectional, observational pilot study was done in 10 children, ages 3 months to 17 years. Each child had a clinical or genetic diagnosis of HI on stable medical therapy. Participants were asked to continue their usual POCT blood glucose monitoring, as well as wear a blinded Dexcom G6® CGM during a 20-day study period with the potential of unblinding if there was severe hypoglycemia detected during the study trial.

RESULTS

During the study period, 26 hypoglycemic events were noted by CGM in 60 % of the participants with 45 % occurring between 0600 and 0800.

CONCLUSIONS

CGM can help detect hypoglycemia and blood glucose trends during a time when there is usually no POCT, which can guide medical management. 30 % of our population had a dose adjustment in their medications. This study was limited by population size.

Status of continuous glucose monitoring use and management in tertiary hospitals of China: a cross-sectional study

OBJECTIVE

This study aims to reveal the use and management status of continuous glucose monitoring (CGM) in tertiary hospitals in China and to determine the potential factors affecting the application of CGM, based on which more effective solutions would be produced and implemented.

DESIGN

An online, cross-sectional study was conducted from October 2021 to December 2021.

SETTING

Eighty-three tertiary hospitals in China were involved.

PARTICIPANTS

Eighty-three head nurses and 281 clinical nurses were obtained.

OUTCOME

Current condition of CGM use and management, the factors that hinder the use and management of CGM, scores of current CGM use and management, as well as their influencing factors, were collected.

RESULTS

Among the 83 hospitals surveyed, 57 (68.7%) hospitals used CGM for no more than 10 patients per month. Seventy-three (88.0%) hospitals had developed CGM standard operating procedures, but only 29 (34.9%) hospitals devised emergency plans to deal with adverse effects related to CGM. Comparably, maternal and children's hospitals were more likely to have a dedicated person to assign install CGM than general hospitals (52.2% vs 26.7%). As for the potential causes that hinder the use and management of CGM, head nurses' and nurses' perceptions differed. Head nurses perceived patients' limited knowledge about CGM (60.2%), the high costs of CGM and inaccessibility to medical insurance (59.0%), and imperfect CGM management systems (44.6%) as the top three factors. Different from head nurses, CGM operation nurses considered the age of CGM operators, the type of hospital nurses worked in, the number of patients using CGM per month and the number of CGM training sessions as potential factors (p<0.05).

CONCLUSIONS

The study provides a broad view of the development status of CGM in China. Generally speaking, the use and management of CGM in China are not yet satisfactory, and more efforts are wanted for improvement.

Continuous glucose monitoring for children with hypoglycaemia: Evidence in 2023

In 2023, childhood hypoglycaemia remains a major public health problem and significant risk factor for consequent adverse neurodevelopment. Irrespective of the underlying cause, key elements of clinical management include the detection, prediction and prevention of episodes of hypoglycaemia. These tasks are increasingly served by Continuous Glucose Monitoring (CGM) devices that measure subcutaneous glucose at near-continuous frequency. While the use of CGM in type 1 diabetes is well established, the evidence for widespread use in rare hypoglycaemia disorders is less than convincing. However, in the few years since our last review there have been multiple developments and increased user feedback, requiring a review of clinical application. Despite advances in device technology, point accuracy of CGM remains low for children with non-diabetes hypoglycaemia. Simple provision of CGM devices has not replicated the efficacy seen in those with diabetes and is yet to show benefit. Machine learning techniques for hypoglycaemia prevention have so far failed to demonstrate sufficient prediction accuracy for real world use even in those with diabetes. Furthermore, access to CGM globally is restricted by costs kept high by the commercially-driven speed of technical innovation. Nonetheless, the ability of CGM to digitally phenotype disease groups has led to a better understanding of natural history of disease, facilitated diagnoses and informed changes in clinical management. Large CGM datasets have prompted re-evaluation of hypoglycaemia incidence and facilitated improved trial design. Importantly, an individualised approach and focus on the behavioural determinants of hypoglycaemia has led to real world reduction in hypoglycaemia. In this state of the art review, we critically analyse the updated evidence for use of CGM in non-diabetic childhood hypoglycaemia disorders since 2020 and provide suggestions for qualified use.

Families' Experiences of Continuous Glucose Monitoring in the Management of Congenital Hyperinsulinism: A Thematic Analysis

BACKGROUND AND AIMS

In patients with congenital hyperinsulinism (CHI), recurrent hypoglycaemia can lead to longstanding neurological impairments. At present, glycaemic monitoring is with intermittent fingerprick blood glucose testing but this lacks utility to identify patterns and misses hypoglycaemic episodes between tests. Although continuous glucose monitoring (CGM) is well established in type 1 diabetes, its use has only been described in small studies in patients with CHI. In such studies, medical perspectives have been provided without fully considering the views of families using CGM. In this qualitative study, we aimed to explore families' experiences of using CGM in order to inform future clinical strategies for the management of CHI.

METHODS

Ten patients with CHI in a specialist centre used CGM for twelve weeks. All were invited to participate. Semi-structured interviews were conducted with nine families in whom patient ages ranged between two and seventeen years. Transcripts of the audio-recorded interviews were analysed using an inductive thematic analysis method.

RESULTS

Analysis revealed five core themes: CGM's function as an educational tool; behavioural changes; positive experiences; negative experiences; and design improvements. Close monitoring and retrospective analysis of glucose trends allowed for enhanced understanding of factors that influenced glucose levels at various times of the day. Parents noted more hypoglycaemic episodes than previously encountered through fingerprick tests; this new knowledge prompted modification of daily routines to prevent and improve the management of hypoglycaemia. CGM use was viewed favourably as offering parental reassurance, reduced fingerprick tests and predictive warnings. However, families also reported unfavourable aspects of alarms and questionable accuracy at low glucose levels. Adolescents were frustrated by the short proximity range for data transmission resulting in the need to always carry a separate receiver. Overall, families were positive about the use of CGM but expected application to be tailored to their child's medical condition.

CONCLUSIONS

Patients and families with CHI using CGM noticed trends in glucose levels which motivated behavioural changes to reduce hypoglycaemia with advantages outweighing disadvantages. They expected CHI-specific modifications to enhance utility. Future design of CGM should incorporate end users' opinions and experiences for optimal glycaemic monitoring of CHI.

The hypoglycaemia error grid: A UK-wide consensus on CGM accuracy assessment in hyperinsulinism

OBJECTIVE

Continuous Glucose Monitoring (CGM) is gaining in popularity for patients with paediatric hypoglycaemia disorders such as Congenital Hyperinsulinism (CHI), but no standard measures of accuracy or associated clinical risk are available. The small number of prior assessments of CGM accuracy in CHI have thus been incomplete. We aimed to develop a novel Hypoglycaemia Error Grid (HEG) for CGM assessment for those with CHI based on expert consensus opinion applied to a large paired (CGM/blood glucose) dataset.

DESIGN AND METHODS

Paediatric endocrinology consultants regularly managing CHI in the two UK centres of excellence were asked to complete a questionnaire regarding glucose cutoffs and associated anticipated risks of CGM errors in a hypothetical model. Collated information was utilised to mathematically generate the HEG which was then approved by expert, consensus opinion. Ten patients with CHI underwent 12 weeks of monitoring with a Dexcom G6 CGM and self-monitored blood glucose (SMBG) with a Contour Next One glucometer to test application of the HEG and provide an assessment of accuracy for those with CHI.

RESULTS

CGM performance was suboptimal, based on 1441 paired values of CGM and SMBG showing Mean Absolute Relative Difference (MARD) of 19.3% and hypoglycaemia (glucose <3.5mmol/L (63mg/dL)) sensitivity of only 45%. The HEG provided clinical context to CGM errors with 15% classified as moderate risk by expert consensus when data was restricted to that of practical use. This provides a contrasting risk profile from existing diabetes error grids, reinforcing its utility in the clinical assessment of CGM accuracy in hypoglycaemia.

CONCLUSIONS

The Hypoglycaemia Error Grid, based on UK expert consensus opinion has demonstrated inadequate accuracy of CGM to recommend as a standalone tool for routine clinical use. However, suboptimal accuracy of CGM relative to SMBG does not detract from alternative uses of CGM in this patient group, such as use as a digital phenotyping tool. The HEG is freely available on GitHub for use by other researchers to assess accuracy in their patient populations and validate these findings.