Continuous Glucose Monitoring in the Management of Neonates With Persistent Hypoglycemia and Congenital Hyperinsulinism

Fifteen-minute consultation: Investigation and management of hypoglycaemia in the term-born infant

Hypoglycaemia in term infants is very common. Deciding on appropriate investigations and management is often challenging. The aims of this article are to help with understanding when, how and why to investigate symptoms of hypoglycaemia in full-term infants (born ≥37 weeks' gestational age).

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.

Association between continuous glucose profile during therapeutic hypothermia and unfavorable outcome in neonates with hypoxic-ischemic encephalopathy209 23-32

BACKGROUND

The detection and management of blood glucose abnormalities in high-risk neonates are crucial for clinical care. The objective of the study was to investigate the continuous glucose profile of hypoxic-ischemic encephalopathy (HIE) patients in the whole-process of therapeutic hypothermia (TH) and its association with clinical and neurological outcomes.

METHOD

In this single-center retrospective study, HIE patients who received both TH and continuous glucose monitoring (CGM) were recruited from March 2016 to September 2021.

RESULTS

Of 47 neonates recruited, 24 had unfavorable outcome. Dysglycemia was most prevalent in the first 24 h of TH, among which hyperglycemia occurred more frequently. CGM showed that the duration, episodes and area under curve (AUC) of hypoglycemia were statistically different in neonates with different outcomes. The occurrence, longer duration, greater AUC of hypoglycemia and an early high coefficient of variation (CV%, CV = SD/mean) were associated with unfavorable outcomes (aOR 26.55 [2.02-348.5], aOR 2.11 [1.08-4.14], aOR 1.80 [1.11-2.91] and aOR respectively), while hyperglycemia was not.

CONCLUSION

During the whole process of TH, hypoglycemia and early unstable glycemic variability were strongly associated with unfavorable outcomes. CGM can instantly detect dysglycemia and facilitate precise glucose management in HIE neonates.

Accuracy and impact on quality of life of real-time continuous glucose monitoring in children with hyperinsulinaemic hypoglycaemia

Objective

Continuous glucose monitoring (CGM) is the standard of care for glucose monitoring in children with diabetes, however there are limited data reporting their use in hyperinsulinaemic hypoglycaemia (HH). Here, we evaluate CGM accuracy and its impact on quality of life in children with HH.

Methods

Real-time CGM (Dexcom G5 and G6) was used in children with HH aged 0-16years. Data from self-monitoring capillary blood glucose (CBG) and CGM were collected over a period of up to 28days and analysed. Quality of life was assessed by the PedsQL4.0 general module and PedsQL2.0 family impact module, completed by children and their parents/carers before and after CGM insertion. Analysis of accuracy metrics included mean absolute relative difference (MARD) and proportion of CGM values within 15, 20, and 30% or 15, 20, and 30 mg/dL of reference glucose values >100 mg/dL or ≤100 mg/dL, respectively (% 15/15, % 20/20, % 30/30). Clinical reliability was assessed with Clarke error grid (CEG) analyses.

Results

Prospective longitudinal study with data analysed from 40 children. The overall MARD between reference glucose and paired CGM values (n=4,928) was 13.0% (Dexcom G5 12.8%, Dexcom G6 13.1%). The proportion of readings meeting %15/15 and %20/20 were 77.3% and 86.4%, respectively, with CEG analysis demonstrating 97.4% of all values in zones A and B. Within the hypoglycaemia range (<70 mg/dL), the median ARD was 11.4% with a sensitivity and specificity of 64.2% and 91.3%, respectively. Overall PedsQL child report at baseline and endpoint were 57.6 (50.5 - 75.8) and 87.0 (82.9 - 91.2), and for parents were 60.3 (44.8 - 66.0) and 85.3 (83.7 - 91.3), respectively (both p<0.001).

Conclusion

Use of CGM for children with HH is feasible, with clinically acceptable accuracy, particularly in the hypoglycaemic range. Quality of life measures demonstrate significant improvement after CGM use. These data are important to explore use of CGM in disease indications, including neonatal and paediatric diabetes, cystic fibrosis and glycogen storage disorders.

Glucose variability in 6-12-month-old healthy infants

Background

Metabolic programming of glucose homeostasis in the first 1,000 days of life may impact lifelong metabolic and cardiovascular health. Continuous glucose monitoring (CGM) devices may help measure the impact of dietary intake on glucose rhythms and metabolism in infants during the complementary feeding period.

Objectives

Demonstrate the feasibility of CGM to measure and quantify glucose variability in response to infant feeding and to evaluate associations between macronutrient meal composition and glucose variability.

Methods

The "FreeStyle Libre Pro^®" device interstitial glucose meter was applied to the anterior thigh of 10 healthy 6-12-month-old infants. Parents recorded food intake, time of feeding, and used daily dairies to record sleep time and duration. Descriptive statistics were employed for food intake, sleep and key glycemic parameters over three full days. Mixed linear models were used to assess glycemic changes.

Results

Mid-day, afternoon, and evening feeds contained >30 g carbohydrate and induced higher 2-h iAUC (3.42, 3.41, and 3.50 mmol/L*h respectively) compared to early and mid-morning feedings with ≤25 g carbohydrates (iAUC 2.72 and 2.81 mmol/L*h, p < 0.05). Early morning and evening milk feedings contained approximately 9 g of fat and induced a longer time to reach maximal glucose value (Tmax; 75 and 68 min, respectively) compared to lower fat feedings (2.9-5.9 g; Tmax range: 34-60 min; p < 0.05). Incremental glucose value at time of food intake (C0) increased significantly from 0.24 ± 0.39 mM in early morning to 1.07 ± 0.57 mM in the evening (p < 0.05). Over the day, 70% of glucose values remained within the normal range (3.5-5.5 mmol/L), 10% were between 5.5-10 mmol/L, and 20% were < 3.5 mmol/L.

Conclusion

Our data support the feasibility of using CGM to measure glucose in 6-12-month-old infants. The observation of possible diurnal glucose variability and typical glucose values may have implications for future studies investigating metabolic adaptation to nutritional intake in early life.

High-Resolution and Multidimensional Phenotypes Can Complement Genomics Data to Diagnose Diseases in the Neonatal Population

Advances in genomic medicine have greatly improved our understanding of human diseases. However, phenome is not well understood. High-resolution and multidimensional phenotypes have shed light on the mechanisms underlying neonatal diseases in greater details and have the potential to optimize clinical strategies. In this review, we first highlight the value of analyzing traditional phenotypes using a data science approach in the neonatal population. We then discuss recent research on high-resolution, multidimensional, and structured phenotypes in neonatal critical diseases. Finally, we briefly introduce current technologies available for the analysis of multidimensional data and the value that can be provided by integrating these data into clinical practice. In summary, a time series of multidimensional phenome can improve our understanding of disease mechanisms and diagnostic decision-making, stratify patients, and provide clinicians with optimized strategies for therapeutic intervention; however, the available technologies for collecting multidimensional data and the best platform for connecting multiple modalities should be considered.

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.

Should continuous glucose monitoring be used to manage neonates at risk of hypoglycaemia?

The National Institute for Clinical Excellence (NICE) now recommends that continuous glucose monitoring (CGM) be offered to adults and children with diabetes who are at risk from hypoglycaemia. Hypoglycaemia is common in the neonatal period, and is a preventable cause of poor neurodevelopmental outcome, but is CGM helpful in the management of neonates at risk of hypoglycaemia? Neonatal studies have shown that CGM can detect clinically silent hypoglycaemia, which has been associated with reduced executive and visual function in early childhood. Intervention trials have further shown CGM can support the targeting of glucose levels in high-risk extremely preterm neonates. In spite of significant advances in technology, including smaller sensors, better accuracy and factory calibration, further progress and adoption into clinical practice has been limited as current devices are not designed nor have regulatory approval for the specific needs of the newborn. The use of CGM has the potential to support clinical management, and prevention of hypoglycaemia but must be set within its current limitations. The data CGM provides however also provides an important opportunity to improve our understanding of potential risks of hypoglycaemia and the impact of clinical interventions to prevent it.

Continuous glucose monitoring during therapeutic hypothermia for hypoxic ischaemic encephalopathy: a feasibility study

OBJECTIVES

Glucose dysregulation is common in infants with hypoxic ischaemic encephalopathy (HIE) and is likely to exacerbate cerebral injury. Infrequent measurement of glucose concentrations makes both identification and prevention of this risk challenging. Continuous glucose monitoring (CGM) has the potential to address both these challenges, but has not been explored in these infants. We aimed to evaluate the feasibility and potential impact of real-time CGM in term infants with HIE being treated with therapeutic hypothermia (TH).

DESIGN

Feasibility study.

SETTING

Tertiary-level neonatal unit, UK.

PATIENTS

Term infants with HIE undergoing TH.

INTERVENTION

A CGM sensor was inserted within 48 hours of birth and kept in situ for the first week of life. Clinical staff were blinded to the CGM recordings and clinical decisions were based on blood glucose assays.

MAIN OUTCOME MEASURES

(1) Accuracy of CGM values during and post TH, (2) Per cent of time spent outside the clinical range (2.6-10 mmol/L), (3) Episodes of hypoglycaemia and hyperglycaemia, (4) Adverse effects.

RESULTS

The accuracy of CGM values during TH were comparable to those when infants were normothermic. There was wide variation in per cent time outside the target range (2.6-10 mmol/L) between infants (median 5%, range 0%-34%). CGM identified 44% of infants with ≥1 episode of hypoglycaemia (<2.6 mmol/L) and 50% with ≥1 episode of hyperglycaemia (>10 mmol/L). No adverse events were observed.

CONCLUSIONS

This study demonstrates that CGM could be a useful adjunct for glucose monitoring in babies undergoing TH who are at risk of both hypoglycaemia and hyperglycaemia.

Continuous glucose monitoring in an infant with panhypopituitarism having hypoglycemia on growth hormone therapy

OBJECTIVES

The usefulness of continuous glucose monitoring (CGM) in infants with panhypopituitarism (PH) having hypoglycemia is yet to be explored. The potential adverse effects of growth hormone (GH) replacement therapy, such as hyperglycemia, cannot be comprehensively evaluated using the conventional measurement.

CASE PRESENTATION

A 2-month-old infant with PH, including severe GH deficiency, had hypoglycemia despite frequent feeding. Glucose levels were monitored using CGM before and after GH replacement therapy. The proportion of time for hypoglycemia decreased from 4.9 to 0% (p<0.017). Hyperglycemia did not increase. The CGM method did not contribute to any adverse events requiring intervention. Our patient only experienced minor bleeding and no episode of cellulitis.

CONCLUSIONS

CGM is useful in controlling glucose levels in infants with hypoglycemia and PH.

Continuous Glucose Monitoring in Preterm Infants: The Role of Nutritional Management in Minimizing Glycemic Variability

Glycemic variability (GV) is common in preterm infants. In the premature population, GV is a risk factor for morbidity and mortality. Both hypo- and hyperglycemia can impair neurodevelopment. We investigated the impact of continuous versus intermittent tube enteral feeding on GV. In our prospective observational study, 20 preterm infants with a gestational age ≤ 34 weeks at either continuous or intermittent bolus full enteral feeding. For five days, continuous glucose monitoring (CGM) was utilized, which was achieved through the subcutaneous insertion of a sensor. A total of 27,532 measurements of blood glucose were taken. The mean amplitude of glycemic excursions did not differ between the two cohorts statistically. Continuous feeding resulted in higher positive values, increasing the risk of hypo- and hyperglycemia. Subjects who were small for their gestational age had a higher standard deviation during continuous feeding (p = 0.001). Data suggest that intermittent bolus nutrition is better for glycemic control than continuous nutrition. Nutritional management optimization of preterm infants appears to be critical for long-term health. In the future, CGM may provide a better understanding of the optimal glucose targets for various clinical conditions, allowing for a more personalized approach to management.

Congenital hyperinsulinism in clinical practice: From biochemical pathophysiology to new monitoring techniques

Congenital hyperinsulinism comprises a group of diseases characterized by a persistent hyperinsulinemic hypoglycemia, due to mutation in the genes involved in the regulation of insulin secretion. The severity and the duration of hypoglycemic episodes, primarily in the neonatal period, can lead to neurological impairment. Detecting blood sugar is relatively simple but, unfortunately, symptoms associated with hypoglycemia may be non-specific. Research in this field has led to novel insight in diagnosis, monitoring and treatment, leading to a better neurological outcome. Given the increased availability of continuous glucose monitoring systems that allow glucose level recognition in a minimally invasive way, monitoring the glycemic trend becomes easier and there are more possibilities of a better follow-up of patients. We aim to provide an overview of new available technologies and new discoveries and their potential impact on clinical practice, convinced that only with a better awareness of the disease and available tools we can have a better impact on CHI diagnosis, prevention and clinical sequelae.

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.

Phosphomannomutase 2 hyperinsulinemia: Recent advances of genetic pathogenesis, diagnosis, and management

Congenital hyperinsulinemia (CHI), is a clinically heterogeneous disorder that presents as a major cause of persistent and recurrent hypoglycemia during infancy and childhood. There are 16 subtypes of CHI-related genes. Phosphomannomutase 2 hyperinsulinemia (PMM2-HI) is an extremely rare subtype which is first reported in 2017, with only 18 families reported so far. This review provides a structured description of the genetic pathogenesis, and current diagnostic and therapeutic advances of PMM2-HI to increase clinicians' awareness of PMM2-HI.

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.