A retrospective in-depth analysis of continuous glucose monitoring datasets for patients with hepatic glycogen storage disease: Recommended outcome parameters for glucose management

Continuous glucose monitoring in patients with inherited metabolic disorders at risk for Hypoglycemia and Nutritional implications

Managing Inherited Metabolic Disorders (IMDs) at risk for hypoglycemia, such as Glycogen Storage Diseases (GSDs), Hereditary Fructose Metabolism Disorders (HFMDs) and Congenital Hyperinsulinism (CH), poses challenges in dietary treatments and blood glucose monitoring. The effectiveness of Continuous Glucose Monitoring (CGM) remains a subject of ongoing debate, with IMD guidelines maintaining caution. Therefore, a systematic evaluation is needed to understand the potential benefits of CGM during dietary interventions. A systematic literature review was conducted in PubMed according to the PICOS model and PRISMA recommendations on studies published from January 01, 2003, up to October 15, 2023 (PROSPERO CRD42024497744). The risk of bias was assessed using NIH Quality Assessment Tools. Twenty-four studies in GSDs (n = 13), CH (n = 10), and HFMDs (n = 1) were analyzed. In GSDs, Real-time CGM (Rt-CGM) was associated with metabolic benefits during nutritional interventions, proving to be an accurate system for hypoglycemia detection although with some concerns about reliability. Rt-CGM in CH, primarily involving children, also showed potential benefits for glycemic control and metabolic stability with acceptable accuracy, although its use during dietary changes was limited. Few experiences on Flash Glucose Monitoring (FGM) were reported, with some concerns about reliability. Overall, the studies analyzed presented different designs, and their quality was predominantly fair or poor. Heterogeneity and limited consensus on reliability and glycemic targets underscore the need for prospective studies and future recommendations for the use of CGM in optimizing nutritional status and providing personalized dietary education in individuals with IMDs prone to hypoglycemia.

Continuous glucose monitoring metrics in people with liver glycogen storage disease and idiopathic ketotic hypoglycemia: A single-center, retrospective, observational study

BACKGROUND

Cohort data on continuous glucose monitoring (CGM) metrics are scarce for liver glycogen storage diseases (GSDs) and idiopathic ketotic hypoglycemia (IKH). The aim of this study was to retrospectively describe CGM metrics for people with liver GSDs and IKH.

PATIENTS AND METHODS

CGM metrics (descriptive, glycemic variation and glycemic control parameters) were calculated for 47 liver GSD and 14 IKH patients, categorized in cohorts by disease subtype, age and treatment status, and compared to published age-matched CGM metrics from healthy individuals. Glycemic control was assessed as time-in-range (TIR; ≥3.9 - ≤7.8 and ≥3.9 - ≤10.0 mmol/L), time-below-range (TBR; <3.0 mmol/L and ≥3.0 - ≤3.9 mmol/L), and time-above-range (TAR; >7.8 and >10.0 mmol/L).

RESULTS

Despite all patients receiving dietary treatment, GSD cohorts displayed significantly different CGM metrics compared to healthy individuals. Decreased TIR together with increased TAR were noted in GSD I, GSD III, and GSD XI (Fanconi-Bickel syndrome) cohorts (all p < 0.05). In addition, all GSD I cohorts showed increased TBR (all p < 0.05). In GSD IV an increased TBR (p < 0.05) and decreased TAR were noted (p < 0.05). In GSD IX only increased TAR was observed (p < 0.05). IKH patient cohorts, both with and without treatment, presented CGM metrics similar to healthy individuals.

CONCLUSION

Despite dietary treatment, most liver GSD cohorts do not achieve CGM metrics comparable to healthy individuals. International recommendations on the use of CGM and clinical targets for CGM metrics in liver GSD patients are warranted, both for patient care and clinical trials.

Endocrine involvement in hepatic glycogen storage diseases: pathophysiology and implications for care

Hepatic glycogen storage diseases constitute a group of disorders due to defects in the enzymes and transporters involved in glycogen breakdown and synthesis in the liver. Although hypoglycemia and hepatomegaly are the primary manifestations of (most of) hepatic GSDs, involvement of the endocrine system has been reported at multiple levels in individuals with hepatic GSDs. While some endocrine abnormalities (e.g., hypothalamic‑pituitary axis dysfunction in GSD I) can be direct consequence of the genetic defect itself, others (e.g., osteopenia in GSD Ib, insulin-resistance in GSD I and GSD III) may be triggered by the (dietary/medical) treatment. Being aware of the endocrine abnormalities occurring in hepatic GSDs is essential (1) to provide optimized medical care to this group of individuals and (2) to drive research aiming at understanding the disease pathophysiology. In this review, a thorough description of the endocrine manifestations in individuals with hepatic GSDs is presented, including pathophysiological and clinical implications.

Short and long-term acceptability and efficacy of extended-release cornstarch in the hepatic glycogen storage diseases: results from the Glyde study

BACKGROUND

Hypoglycaemia is the primary manifestation of all the hepatic types of glycogen storage disease (GSD). In 2008, Glycosade®, an extended-release waxy maize cornstarch, was reported as an alternative to uncooked cornstarch (UCCS) which could prolong the duration of fasting in the GSD population. To date, there has been minimal published experience in (a) young children, (b) the ketotic forms of GSD, and (c) with daytime dosing. The Glyde study was created as a prospective, global initiative to test the efficacy and tolerance of Glycosade use across a broader and more diverse population.

METHODS

A randomised double-blind cross-over fasting study assessing the tolerance and efficacy of Glycosade compared with cornstarch was performed across disease types and ages. Participants and clinicians chose the product deemed superior, whilst still blinded. Participants were followed for 2 years to assess long-term metabolic control, growth, and quality of life.

RESULTS

Sixty-one participants (age 2-62 years; 59% female) were enrolled, and 58 participants completed the fasting studies (28 GSD I; 30 GSD III, VI, IX). Glycosade improved duration of fasting in GSD I and duration of fasting without ketosis in the ketotic forms. Chronic Glycosade use was chosen by 69% of participants. Those treated with Glycosade for the 2-year chronic phase used fewer doses of therapy while markers of metabolic control remained stable.

CONCLUSION

The Glyde study is the first multi-centre international trial demonstrating the efficacy and tolerance of Glycosade in a large cohort of hepatic GSD patients across a diverse international population. The ability to use fewer doses of therapy per day and avoidance of overnight therapy may improve compliance, safety, and quality of life without sacrificing metabolic control.

Synergistic detoxification efficiency and mechanism of triclocarban degradation by a bacterial consortium in the liver-gut-microbiota axis of zebrafish (Danio rerio)

Triclocarban (TCC), an emerging organic contaminant, poses a potential threat to human health with long-term exposure. Here, Rhodococcus rhodochrous BX2 and Pseudomonas sp. LY-1 were utilized to degrade TCC at environmental related concentrations for enhancing TCC biodegradation and investigating whether the toxicity of intermediate metabolites is lower than that of the parent compound. The results demonstrated that the bacterial consortium could degrade TCC by 82.0% within 7 days. The calculated 96 h LC50 for TCC, as well as its main degradation product 3,4-Dichloroaniline (DCA) were 0.134 mg/L and 1.318 mg/L respectively. Biodegradation also alleviated histopathological lesions induced by TCC in zebrafish liver and gut tissues. Liver transcriptome analysis revealed that biodegradation weakened differential expression of genes involved in disrupted immune regulation and lipid metabolism caused by TCC, verified through RT-qPCR analysis and measurement of related enzyme activities and protein contents. 16 S rRNA sequencing indicated that exposure to TCC led to gut microbial dysbiosis, which was efficiently improved through TCC biodegradation, resulting in decreased relative abundances of major pathogens. Overall, this study evaluated potential environmental risks associated with biodegradation of TCC and explored possible biodetoxification mechanisms, providing a theoretical foundation for efficient and harmless bioremediation of environmental pollutants.

Dapagliflozin and Empagliflozin in Paediatric Indications: A Systematic Review

INTRODUCTION

In adults, sodium-glucose cotransporter type 2 inhibitors have revolutionised the treatment of type 2 diabetes mellitus, heart failure, and chronic kidney disease.

OBJECTIVE

We aimed to review information on compassionate use, clinical pharmacology, efficacy, and safety of dapagliflozin and empagliflozin in children.

METHODS

We conducted a systematic review of published clinical trials, case reports, and observational studies in Medline, Excerpta Medica, and Web of Science databases from inception to September 2023. For the two randomised controlled trials on type 2 diabetes mellitus (T2DM), we implemented a meta-analysis on the primary outcome (mean difference in glycosylated haemoglobin [HbA1c] between intervention and placebo groups). Review Manager (RevMan), version 5.4.1, was used for this purpose.

RESULTS

Thirty-five articles (nine case reports, ten case series, one prospective non-controlled trial, four controlled randomised trials, two surveys, six pharmacokinetic studies, and three pharmacovigilance studies) were selected, in which 415 children were exposed to either dapagliflozin or empagliflozin: 189 diabetic patients (mean age 14.7 ± 2.9 years), 32 children with glycogen storage disease type Ib (GSD Ib), glucose-6-phosphatase catalytic subunit 3 (G6PC3) deficiency, or severe congenital neutropenia type 4 (8.5 ± 5.1 years), 47 children with kidney disease or heart failure (11.2 ± 6.1 years), 84 patients in pharmacokinetic studies (15.1 ± 2.3 years), and 63 patients in toxicological series. The effect of dapagliflozin and empagliflozin in T2DM was demonstrated by HbA1c reduction in two randomised trials among a total of 177 adolescents, with a mean HbA1c difference of -0.82% (95% confidence interval -1.34 to -0.29) as compared to placebo (no heterogeneity, I2 = 0%). Dosage ranged between 5 and 20 mg (mean 11.4 ± 3.7) once daily for dapagliflozin and between 5 and 25 mg (mean 15.4 ± 7.4) once daily for empagliflozin. Among the paediatric cases of GSD Ib, empagliflozin 0.1-1.3 mg/kg/day improved neutropenia, infections, and gastrointestinal health. Dapagliflozin (mean dosage 6.9 ± 5.2 mg once daily) was well-tolerated in children with chronic kidney disease and heart failure. Side effects were generally mild, the most frequent being hypoglycaemia in children with GSD Ib (33% of patients) or T2DM (14% of patients) on concomitant hypoglycaemic drugs. Diabetic ketoacidosis is rare in children.

CONCLUSION

Early evidence suggests that dapagliflozin and empagliflozin are well tolerated in children. A clinical pharmacology rationale currently exists only for adolescents with diabetes mellitus.

PROSPERO REGISTRATION NUMBER

CRD42023438162.

Endogenous Glucose Production in Patients With Glycogen Storage Disease Type Ia Estimated by Oral D-[6,6-2H2]-glucose

CONTEXT

Glycogen storage disease type Ia (GSDIa) is an inborn metabolic disorder characterized by impaired endogenous glucose production (EGP). Monitoring of patients with GSDIa is prioritized because of ongoing treatment developments. Stable isotope tracers may enable reliable EGP monitoring.

OBJECTIVE

The aim of this study was to prospectively assess the rate of appearance of endogenous glucose into the bloodstream (Ra) in patients with GSDIa after a single oral D-[6,6-2H2]-glucose dose.

METHODS

Ten adult patients with GSDIa and 10 age-, sex-, and body mass index-matched healthy volunteers (HVs) were enrolled. For each participant, 3 oral glucose tracer tests were performed: (1) preprandial/fasted, (2) postprandial, and (3) randomly fed states. Dried blood spots were collected before D-[6,6-2H2]-glucose administration and 10, 20, 30, 40, 50, 60, 75, 90, and 120 minutes thereafter.

RESULTS

Glucose Ra in fasted HVs was consistent with previously reported data. The time-averaged glucose Ra was significantly higher in (1) preprandial/fasted patients with GSDIa than HV and (2) postprandial HV compared with fasted HV(P < .05). A progressive decrease in glucose Ra was observed in preprandial/fasted patients with GSDIa; the change in glucose Ra time-course was directly correlated with the change in capillary glucose (P < .05).

CONCLUSION

This is the first study to quantify glucose Ra in patients with GSDIa using oral D-[6,6-2H2] glucose. The test can reliably estimate EGP under conditions in which fasting tolerance is unaffected but does not discriminate between relative contributions of EGP (eg, liver, kidney) and exogenous sources (eg, dietary cornstarch). Future application is warranted for longitudinal monitoring after novel genome based treatments in patients with GSDIa in whom nocturnal dietary management can be discontinued.

Use of Continuous Glucose Monitors by People Without Diabetes: An Idea Whose Time Has Come?

BACKGROUND

Continuous glucose monitor (CGM) systems were originally intended only for people with diabetes. Recently, there has been interest in monitoring glucose concentrations in a variety of other situations. As data accumulate to support the use of CGM systems in additional states unrelated to diabetes, the use of CGM systems is likely to increase accordingly.

METHODS

PubMed and Google Scholar were searched for articles about the use of CGM in individuals without diabetes. Relevant articles that included sufficient details were queried to identify what cohorts of individuals were adopting CGM use and to define trends of use.

RESULTS

Four clinical user cases were identified: (1) metabolic diseases related to diabetes with a primary dysregulation of the insulin-glucose axis, (2) metabolic diseases without a primary pathophysiologic derangement of the insulin-glucose axis, (3) health and wellness, and (4) elite athletics. Seven trends in the use of CGM systems in people without diabetes were idenfitied which pertained to both FDA-cleared medical grade products as well as anticipated future products, which may be regulated differently based on intended populations and indications for use.

CONCLUSIONS

Wearing a CGM has been used not only for diabetes, but with a goal of improving glucose patterns to avoid diabetes, improving mental or physical performance, and promoting motivate healthy behavioral changes. We expect that clinicians will become increasingly aware of (1) glycemic patterns from CGM tracings that predict an increased risk of diabetes, (2) specific metabolic glucotypes from CGM tracings that predict an increased risk of diabetes, and (3) new genetic and genomic biomarkers in the future.

Glycogen storage diseases

Glycogen storage diseases (GSDs) are a group of rare, monogenic disorders that share a defect in the synthesis or breakdown of glycogen. This Primer describes the multi-organ clinical features of hepatic GSDs and muscle GSDs, in addition to their epidemiology, biochemistry and mechanisms of disease, diagnosis, management, quality of life and future research directions. Some GSDs have available guidelines for diagnosis and management. Diagnostic considerations include phenotypic characterization, biomarkers, imaging, genetic testing, enzyme activity analysis and histology. Management includes surveillance for development of characteristic disease sequelae, avoidance of fasting in several hepatic GSDs, medically prescribed diets, appropriate exercise regimens and emergency letters. Specific therapeutic interventions are available for some diseases, such as enzyme replacement therapy to correct enzyme deficiency in Pompe disease and SGLT2 inhibitors for neutropenia and neutrophil dysfunction in GSD Ib. Progress in diagnosis, management and definitive therapies affects the natural course and hence morbidity and mortality. The natural history of GSDs is still being described. The quality of life of patients with these conditions varies, and standard sets of patient-centred outcomes have not yet been developed. The landscape of novel therapeutics and GSD clinical trials is vast, and emerging research is discussed herein.

Abnormal glucose homeostasis and fasting intolerance in patients with congenital porto-systemic shunts

In physiological glucose homeostasis, the liver plays a crucial role in the extraction of glucose from the portal circulation and storage as glycogen to enable release through glycogenolysis upon fasting. In addition, insulin secreted by the pancreas is partly eliminated from the systemic circulation by hepatic first-pass. Therefore, patients with a congenital porto-systemic shunt present a unique combination of (a) postabsorptive hyperinsulinemic hypoglycaemia (HH) because of decreased insulin elimination and (b) fasting (ketotic) hypoglycaemia because of decreased glycogenolysis. Patients with porto-systemic shunts therefore provide important insight into the role of the portal circulation and hepatic function in different phases of glucose homeostasis.

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.

Towards values-based healthcare for inherited metabolic disorders: An overview of current practices for persons with liver glycogen storage disease and fatty acid oxidation disorders

Value-based healthcare (VBHC) intends to achieve better outcomes for patients, to improve quality of patient care, with reduced costs. Four dimensions define a model of intimately related value-pillars: personal value, allocative value, technical value, and societal value. VBHC is mostly applied in common diseases, and there are fundamental challenges in applying VBHC strategies to low volume, high complex healthcare situations, such as rare diseases, including inherited metabolic disorders. This article summarizes current practices at various academical domains (i.e., research, healthcare, education, and training) that (aim to) increase values at various value-pillars for persons with liver glycogen storage diseases or fatty acid oxidation disorders and their families. Future perspectives may include facilitating virtual networks to function as integrated practice units, improving measurement of outcomes, and creating information technology platforms to overcome the ethical, legal, societal, and technical challenges of data sharing for healthcare and research purposes.

Using CUSUM in real time to signal clinically relevant decreases in estimated glomerular filtration rate

Background

The electronic health record (EHR), utilized to apply statistical methodology, assists provider decision-making, including during the care of chronic kidney disease (CKD) patients. When estimated glomerular filtration (eGFR) decreases, the rate of that change adds meaning to a patient’s single eGFR and may represent severity of renal injury. Since the cumulative sum chart technique (CUSUM), often used in quality control and surveillance, continuously checks for change in a series of measurements, we selected this statistical tool to detect clinically relevant eGFR decreases and developed CUSUM_GFR.

Methods

In a retrospective analysis we applied an age adjusted CUSUM_GFR, to signal identification of eventual ESKD patients prior to diagnosis date. When the patient signaled by reaching a specified threshold value, days from CUSUM signal date to ESKD diagnosis date (earliness days) were measured, along with the corresponding eGFR measurement at the signal.

Results

Signaling occurred by CUSUM_GFR on average 791 days (se = 12 days) prior to ESKD diagnosis date with sensitivity = 0.897, specificity = 0.877, and accuracy = .878. Mean days prior to ESKD diagnosis were significantly greater in Black patients (905 days) and patients with hypertension (852 days), diabetes (940 days), cardiovascular disease (1027 days), and hypercholesterolemia (971 days). Sensitivity and specificity did not vary by sociodemographic and clinical risk factors.

Conclusions

CUSUM_GFR correctly identified 30.6% of CKD patients destined for ESKD when eGFR was > 60 ml/min/1.73 m² and signaled 12.3% of patients that did not go on to ESKD (though almost all went on to later-stage CKD). If utilized in an EHR, signaling patients could focus providers’ efforts to slow or prevent progression to later stage CKD and ESKD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02910-8.

A Prospective Study on Continuous Glucose Monitoring in Glycogen Storage Disease Type Ia: Toward Glycemic Targets

CONTEXT

Although previous research has shown the benefit of continuous glucose monitoring (CGM) for hepatic glycogen storage diseases (GSDs), current lack of prospectively collected CGM metrics and glycemic targets for CGM-derived outcomes in the hepatic GSD population limits its use.

OBJECTIVE

To assess CGM metrics for glycemic variation and glycemic control in adult patients with GSDIa as compared to matched healthy volunteers.

DESIGN

Prospective CGM data were collected during the ENGLUPRO GSDIa trial (NCT04311307) in which a Dexcom G6 device was used. Ten adult patients with GSDIa and 10 age-, sex- and body mass index-matched healthy volunteers were enrolled. Capillary blood glucose was concurrently measured during 2 standardized 2-hour time intervals. Descriptive [eg, glycemic variability (GV), time below range, time in range (TIR), time above range (TAR)] and advanced (ie, first- and second-order derivatives, Fourier analysis) CGM outcomes were calculated. For each descriptive CGM outcome measure, 95% CIs were computed in patients with GSDIa and healthy volunteers, respectively.

RESULTS

CGM overestimation was higher under preprandial and level 1 hypoglycemia (ie, capillary glucose values ≥ 3.0 mmol/L and < 3.9 mmol/L) conditions. GV and TAR were higher while TIR was lower in patients with GSDIa compared to healthy volunteers (P < 0.05). Three patients with GSDIa showed descriptive CGM outcomes outside the calculated 95% CI in GSDIa patients. Advanced CGM analysis revealed a distinct pattern (ie, first- and second-order derivatives and glucose curve amplitude) in each of these 3 patients within the patients group.

CONCLUSIONS

This is the first study to prospectively compare CGM outcomes between adult patients with GSDIa and matched healthy volunteers. The generation of a set of CGM metrics will provide guidance in using and interpreting CGM data in GSDIa and will be useful for the definition of glycemic targets for CGM in patients with GSDIa. Future studies should investigate the prognostic value of CGM outcomes and their major determinants in patients with GSDIa.

Dynamic Methods for Childhood Hypoglycemia Phenotyping: A Narrative Review

Hypoglycemia results from an imbalance between glucose entering the blood compartment and glucose demand, caused by a defect in the mechanisms regulating postprandial glucose homeostasis. Hypoglycemia represents one of the most common metabolic emergencies in childhood, potentially leading to serious neurologic sequelae, including death. Therefore, appropriate investigation of its specific etiology is paramount to provide adequate diagnosis, specific therapy and prevent its recurrence. In the absence of critical samples for biochemical studies, etiological assessment of children with hypoglycemia may include dynamic methods, such as in vivo functional tests, and continuous glucose monitoring. By providing detailed information on actual glucose fluxes in vivo, proof-of-concept studies have illustrated the potential (clinical) application of dynamic stable isotope techniques to define biochemical and clinical phenotypes of inherited metabolic diseases associated with hypoglycemia. According to the textbooks, individuals with glycogen storage disease type I (GSD I) display the most severe hypoglycemia/fasting intolerance. In this review, three dynamic methods are discussed which may be considered during both diagnostic work-up and monitoring of children with hypoglycemia: 1) functional in vivo tests; 2) in vivo metabolic profiling by continuous glucose monitoring (CGM); 3) stable isotope techniques. Future applications and benefits of dynamic methods in children with hypoglycemia are also discussed.

Inborn errors of metabolism and their impact in paediatric dentistry

The management of paediatric patients with inborn errors of metabolism (IEM) presents an unparalleled challenge for paediatric dentists owing to the multiplex of interrelated dental manifestations and metabolic management necessitating modifications to dental care. Inborn errors of metabolism describe a largely heterogenous group of genetic disorders namely attributable to a single gene defect essential for a specific metabolic pathway. Approximately 400 disorders have been described with an overall incidence of 1 in 5000 live births worldwide. Clinical presentation is classically inconspicuous and insidious in the neonatal period with pathophysiology attributable to accumulation of toxic by-products which interfere with normal function, or insufficient synthesis of essential compounds. This paper aims to discuss the primary oral and maxillofacial manifestations across the scope of inborn errors of metabolism, whilst also considering how metabolic treatment has the propensity to complicate dental management.

The Need to Pair Molecular Monitoring Devices with Molecular Imaging to Personalize Health

By enabling the non-invasive monitoring and quantification of biomolecular processes, molecular imaging has dramatically improved our understanding of disease. In recent years, non-invasive access to the molecular drivers of health versus disease has emboldened the goal of precision health, which draws on concepts borrowed from process monitoring in engineering, wherein hundreds of sensors can be employed to develop a model which can be used to preventatively detect and diagnose problems. In translating this monitoring regime from inanimate machines to human beings, precision health posits that continual and on-the-spot monitoring are the next frontiers in molecular medicine. Early biomarker detection and clinical intervention improves individual outcomes and reduces the societal cost of treating chronic and late-stage diseases. However, in current clinical settings, methods of disease diagnoses and monitoring are typically intermittent, based on imprecise risk factors, or self-administered, making optimization of individual patient outcomes an ongoing challenge. Low-cost molecular monitoring devices capable of on-the-spot biomarker analysis at high frequencies, and even continuously, could alter this paradigm of therapy and disease prevention. When these devices are coupled with molecular imaging, they could work together to enable a complete picture of pathogenesis. To meet this need, an active area of research is the development of sensors capable of point-of-care diagnostic monitoring with an emphasis on clinical utility. However, a myriad of challenges must be met, foremost, an integration of the highly specialized molecular tools developed to understand and monitor the molecular causes of disease with clinically accessible techniques. Functioning on the principle of probe-analyte interactions yielding a transducible signal, probes enabling sensing and imaging significantly overlap in design considerations and targeting moieties, however differing in signal interpretation and readout. Integrating molecular sensors with molecular imaging can provide improved data on the personal biomarkers governing disease progression, furthering our understanding of pathogenesis, and providing a positive feedback loop toward identifying additional biomarkers and therapeutics. Coupling molecular imaging with molecular monitoring devices into the clinical paradigm is a key step toward achieving precision health.

Glycogen Storage Disease Type Ia: Current Management Options, Burden and Unmet Needs

Glycogen storage disease type Ia (GSDIa) is caused by defective glucose-6-phosphatase, a key enzyme in carbohydrate metabolism. Affected individuals cannot release glucose during fasting and accumulate excess glycogen and fat in the liver and kidney, putting them at risk of severe hypoglycaemia and secondary metabolic perturbations. Good glycaemic/metabolic control through strict dietary treatment and regular doses of uncooked cornstarch (UCCS) is essential for preventing hypoglycaemia and long-term complications. Dietary treatment has improved the prognosis for patients with GSDIa; however, the disease itself, its management and monitoring have significant physical, psychological and psychosocial burden on individuals and parents/caregivers. Hypoglycaemia risk persists if a single dose of UCCS is delayed/missed or in cases of gastrointestinal intolerance. UCCS therapy is imprecise, does not treat the cause of disease, may trigger secondary metabolic manifestations and may not prevent long-term complications. We review the importance of and challenges associated with achieving good glycaemic/metabolic control in individuals with GSDIa and how this should be balanced with age-specific psychosocial development towards independence, management of anxiety and preservation of quality of life (QoL). The unmet need for treatment strategies that address the cause of disease, restore glucose homeostasis, reduce the risk of hypoglycaemia/secondary metabolic perturbations and improve QoL is also discussed.