Effects of hypoglycemia on developmental outcome in children with congenital hyperinsulinism

Association of Fetal Catecholamines With Neonatal Hypoglycemia

Importance

Perinatal stress and fetal growth restriction increase the risk of neonatal hypoglycemia. The underlying pathomechanism is poorly understood. In a sheep model, elevated catecholamine concentrations were found to suppress intrauterine insulin secretion, followed by hyperresponsive insulin secretion once the adrenergic stimulus subsided.

Objective

To determine whether neonates with risk factors for hypoglycemia have higher catecholamine concentrations in umbilical cord blood (UCB) and/or amniotic fluid (AF) and whether catecholamines are correlated with postnatal glycemia.

Design, Setting, and Participants

In a prospective cohort study of 328 neonates at a tertiary perinatal center from September 2020 through May 2022 in which AF and UCB were collected immediately during and after delivery, catecholamines and metanephrines were analyzed using liquid chromatography with tandem mass spectrometry. Participants received postnatal blood glucose (BG) screenings.

Exposure

Risk factor for neonatal hypoglycemia.

Main Outcomes and Measures

Comparison of catecholamine and metanephrine concentrations between at-risk neonates and control participants, and correlation of concentrations of catecholamines and metanephrines with the number and severity of postnatal hypoglycemic episodes.

Results

In this study of 328 neonates (234 in the risk group: median [IQR] gestational age, 270 [261-277] days; and 94 in the control group: median [IQR] gestational age, 273 [270-278] days), growth-restricted neonates showed increased UCB median (IQR) concentrations of norepinephrine (21.10 [9.15-42.33] vs 10.88 [5.78-18.03] nmol/L; P < .001), metanephrine (0.37 [0.13-1.36] vs 0.12 [0.08-0.28] nmol/L; P < .001), and 3-methoxytyramine (0.149 [0.098-0.208] vs 0.091 [0.063-0.149] nmol/L; P = .001). Neonates with perinatal stress had increased UCB median (IQR) concentrations of norepinephrine (22.55 [8.99-131.66] vs 10.88 [5.78-18.03] nmol/L; P = .001), normetanephrine (1.75 [1.16-4.93] vs 1.25 [0.86-2.56] nmol/L; P = .004), and 3-methoxytyramine (0.120 [0.085-0.228] vs 0.091 [0.063-0.149] nmol/L; P = .008) (P < .0083 was considered statistically significant). Concentrations of UCB norepinephrine, metanephrine, and 3-methoxytyramine were negatively correlated with AF C-peptide concentration (rs = -0.212, P = .005; rs = -0.182, P = .016; and rs = -0.183, P = .016, respectively [P < .017 was considered statistically significant]). Concentrations of UCB norepinephrine, metanephrine, and 3-methoxytyramine were positively correlated with the number of hypoglycemic episodes (BG concentration of 30-45 mg/dL) (rs = 0.146, P = .01; rs = 0.151, P = .009; and rs = 0.180, P = .002, respectively). Concentrations of UCB metanephrine and 3-methoxytyramine were negatively correlated with the lowest measured BG concentration (rs = -0.149, P = .01; and rs = -0.153, P = .008, respectively).

Conclusions and Relevance

Neonates at risk for hypoglycemia displayed increased catecholamine and metanephrine concentrations that were correlated with postnatal hypoglycemic episodes and lower BG levels; these results are consistent with findings in a sheep model that fetal catecholamines are associated with neonatal β-cell physiology and that perinatal stress or growth restriction is associated with subsequent neonatal hyperinsulinemic hypoglycemia. Improving the pathomechanistic understanding of neonatal hypoglycemia may help to guide management of newborns at risk for hypoglycemia.

Proposed Screening for Congenital Hyperinsulinism in Newborns: Perspective from a Neonatal-Perinatal Medicine Group

This perspective work by academic neonatal providers is written specifically for the audience of newborn care providers and neonatologists involved in neonatal hypoglycemia screening. Herein, we propose adding a screen for congenital hyperinsulinism (CHI) by measuring glucose and ketone (i.e., β-hydroxybutyrate (BOHB)) concentrations just prior to newborn hospital discharge and as close to 48 h after birth as possible, at the same time that the mandated state Newborn Dried Blood Spot Screen is obtained. In the proposed protocol, we do not recommend specific metabolite cutoffs, as our primary objective is to simply highlight the concept of screening for CHI in newborns to newborn caregivers. The premise for our proposed screen is based on the known effect of hyperinsulinism in suppressing ketogenesis, thereby limiting ketone production. We will briefly discuss genetic CHI, other forms of neonatal hypoglycemia, and their shared mechanisms; the mechanism of insulin regulation by functional pancreatic islet cell membrane KATP channels; adverse neurodevelopmental sequelae and brain injury due to missing or delaying the CHI diagnosis; the principles of a good screening test; how current neonatal hypoglycemia screening programs do not fulfill the criteria for being effective screening tests; and our proposed algorithm for screening for CHI in newborns.

Treatment of hypoglycemia due to a rare pathogenic variant in AKT2 with waxy maize heat-modified starch

Key Clinical Message

The gain-of-function AKT2 c.49G>A variant causes hypoketotic hypoglycemia with variable associated features. Due to lack of effective medications, treatment is primarily supportive. This report suggests waxy maize heat is a viable treatment option.

Abstract

The serine-threonine kinase AKT2 is a critical mediator of insulin's anabolic effects, particularly cellular glucose uptake. The gain-of-function c.49G>A, p.(Glu17Lys) AKT2 variant results in hypoketotic hypoglycemia with suppressed insulin and free fatty acid levels due to constitutive activation of the insulin signaling cascade. Although biochemical similarities exist among the eight individuals identified to date, the associated phenotype varies considerably. Treatment of these patients remains challenging, consisting primarily of frequent feeds with uncooked cornstarch. We describe a female with hemihypertrophy, developmental delay, and dysmorphic features who presented to our center with hypoglycemic seizures at age 6 months. Critical sample revealed hypoketotic hypoglycemia, undetectable insulin, and suppressed free fatty acids. Molecular testing confirmed a pathogenic c.49G>A, p.(Glu17Lys) AKT2 mutation. Glycemic control was initially difficult to establish, with recurrent hypoglycemia despite high glucose infusion rates. Following in-hospital administration of waxy maize heat-modified starch at age 4-years, she remained euglycemic overnight, despite a previous report showing no benefit compared to uncooked cornstarch in an infant with the same mutation. Our report suggests waxy maize heat-modified starch is a viable treatment option for patients with activating c.49G>A AKT2 mutations and provides further evidence of a broad phenotypic spectrum.

Potassium channels in behavioral brain disorders. Molecular mechanisms and therapeutic potential: A narrative review

Potassium channels (K+-channels) selectively control the passive flow of potassium ions across biological membranes and thereby also regulate membrane excitability. Genetic variants affecting many of the human K+-channels are well known causes of Mendelian disorders within cardiology, neurology, and endocrinology. K+-channels are also primary targets of many natural toxins from poisonous organisms and drugs used within cardiology and metabolism. As genetic tools are improving and larger clinical samples are being investigated, the spectrum of clinical phenotypes implicated in K+-channels dysfunction is rapidly expanding, notably within immunology, neurosciences, and metabolism. K+-channels that previously were considered to be expressed in only a few organs and to have discrete physiological functions, have recently been found in multiple tissues and with new, unexpected functions. The pleiotropic functions and patterns of expression of K+-channels may provide additional therapeutic opportunities, along with new emerging challenges from off-target effects. Here we review the functions and therapeutic potential of K+-channels, with an emphasis on the nervous system, roles in neuropsychiatric disorders and their involvement in other organ systems and diseases.

New approaches to screening and management of neonatal hypoglycemia based on improved understanding of the molecular mechanism of hypoglycemia

For the past 70 years, controversy about hypoglycemia in newborn infants has focused on a numerical "definition of neonatal hypoglycemia", without regard to its mechanism. This ignores the purpose of screening newborns for hypoglycemia, which is to identify those with pathological forms of hypoglycemia and to prevent hypoglycemic brain injury. Recent clinical and basic research indicates that the three major forms of neonatal hypoglycemia are caused by hyperinsulinism (recognizing also that other rare hormonal or metabolic conditions may also present during this time frame). These include transitional hypoglycemia, which affects all normal newborns in the first few days after birth; perinatal stress-induced hypoglycemia in high-risk newborns, which afflicts ∼1 in 1,200 newborns; and genetic forms of congenital hyperinsulinism which afflict ∼1 in 10,000-40,000 newborns. (1) Transitional hyperinsulinism in normal newborns reflects persistence of the low glucose threshold for insulin secretion during fetal life into the first few postnatal days. Recent data indicate that the underlying mechanism is decreased trafficking of ATP-sensitive potassium channels to the beta-cell plasma membrane, likely a result of the hypoxemic state of fetal life. (2) Perinatal stress-induced hyperinsulinism in high-risk infants appears to reflect an exaggeration of this normal low fetal glucose threshold for insulin release due to more severe and prolonged exposure to perinatal hypoxemia. (3) Genetic hyperinsulinism, in contrast, reflects permanent genetic defects in various steps controlling beta-cell insulin release, such as inactivating mutations of the K _ATP-channel genes. The purpose of this report is to review our current knowledge of these three major forms of neonatal hyperinsulinism as a foundation for the diagnosis and management of hypoglycemia in newborn infants. This includes selection of appropriate interventions based on underlying disease mechanism; combined monitoring of both plasma glucose and ketone levels to improve screening for infants with persistent forms of hypoglycemia; and ultimately to ensure that infants at risk of persistent hyperinsulinemic hypoglycemia are recognized prior to discharge from the nursery.

Natural history and neurodevelopmental outcomes in perinatal stress induced hyperinsulinism

OBJECTIVE

To describe perinatal stress induced hyperinsulinism (PSIHI), determine the prevalence of neurodevelopmental differences, and identify risk factors for poor developmental prognosis.

METHODS

Subjects with a history of hyperinsulinism (HI) and perinatal stress and in whom resolution of the HI was demonstrated were included. Medical record review, caregiver interview, and three validated developmental assessments were completed.

RESULTS

Of the 107 subjects (75% male), 36% were born between 32 and 37 weeks. Median age of hypoglycemia presentation was 0 days. Median age at HI diagnosis was 12 days (IQR 13.5). Median length of time for initiation of definitive treatment was 14 days (IQR 14).Caregiver interviews were completed for 53 of 79 eligible subjects. Developmental concerns were reported by 51%. Neurodevelopmental assessments were completed by caregivers of 37 of the 53 enrolled subjects. The proportion of subjects scoring >1 SD and >2 SD away from the mean in the direction of concern on the major composite scores was significantly greater than in the general population (40.5% vs. 15.8%, P ≤ 0.0001 and 18.9% vs. 2.2%, P ≤ 0.0001, respectively).Male sex, small for gestational age status (SGA), and treatment with continuous feeds were associated with assessment scores >1 SD from the mean (P < 0.05). SGA and preeclampsia were associated with assessment scores >2 SD from the mean (P < 0.05).

CONCLUSION

While the majority of infants presented with hypoglycemia in the first day of life, diagnosis and treatment occurred 12-14 days later. Children with PSIHI are at high risk of neurodevelopmental deficits and are more likely to perform below average on developmental assessment.

Ketogenic diet as elective treatment in patients with drug-unresponsive hyperinsulinemic hypoglycemia caused by glucokinase mutations

Background

Hyperinsulinemic hypoglycemia (HI) is the most frequent cause of recurrent hypoglycemia in children. Despite diagnostic and therapeutic advances, it remains an important cause of morbidity, leading to neurological complications, such as psychomotor retardation and epilepsy. Patients with diffuse drug-unresponsive HI manifest neurological impairment and neurobehavioral problems, even though surgically treated with a near-total pancreatectomy. Based on the analogies between HI and GLUT1 deficiency, both presenting with neuroglycopenia and lack of alternative cerebral energy sources, we administered a ketogenic diet (KD) in three drug-unresponsive GCK-HI patients with the aim of preserving neurodevelopment and avoiding the need of a near-total pancreatectomy. They presented recurrent symptomatic hypoglycemia, intellectual disability and refractory epilepsy. Patients were treated with classical KD for 79, 27 and 18 months, respectively.

Results

All patients became asymptomatic in a few days and showed an important improvement of the alert state. Epilepsy disappeared and no appearance of novel hypoglycemic lesions was detected with a brain MRI. Cognitive and adaptive abilities rapidly improved and normalized. IQ rose significantly from 81 to 111 (p = 0.04) in patient 1, from 82 vs 95 (p = 0.04) in patient 2, from 60 to 90 (p = 0.04) in patient 3.

Conclusions

We demonstrated the safety and efficacy of KD in the treatment of drug-unresponsive GCK-HI at a short and long-term. The neuroprotective effects of KD determined the recovery from epilepsy and intellectual disabilities and averted the need of a near-total pancreatectomy. All patients and their families reported an improvement of physical and psychosocial well-being, with a substantial improvement of their quality of life. These results might change the course and the quality of life of these patients and their families, having a relevant impact on human lives. Therefore, KD might be considered the elective treatment in unresponsive forms of GCK-HI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-02045-3.

Challenges in management of transient hyperinsulinism - a retrospective analysis of 36 severely affected children

OBJECTIVES

Transient hyperinsulinism (THI) is a hypoglycemia disorder which resolves spontaneously within the first weeks or months of life. The pathomechanism of THI is not elucidated yet; however, it is known that perinatal stress predisposes for THI. We aimed to characterize the clinical phenotype and treatment of children with THI, and to identify options for improved management.

METHODS

A retrospective analysis of 36 children with THI treated at the University Children's Hospital Düsseldorf between 2007 and 2019 was performed.

RESULTS

All children had risk factors for neonatal hypoglycemia or indicators of perinatal stress. Eighty three percent were diagnosed with hypoglycemia on day of life (DOL)1. None of the six diagnosed later had routine blood glucose screening and showed significantly lower blood glucose levels at the time of first blood glucose measurement compared to the children diagnosed on DOL1. Ninety seven percent of all children received intravenous glucose, 42% received continuous glucagon and 81% were started on diazoxide. Diazoxide withdrawal and subsequent fasting tests lacked standardization and were based on clinical experience. Three patients had a subsequent episode of hypoglycemia, after fasting studies only demonstrated "clinical" remission without proving the ability to ketogenesis.

CONCLUSIONS

Any kind of perinatal stress might pose a risk to develop THI, and postnatal monitoring for hypoglycemia still needs to be improved. Diazoxide is effective in children with THI; however, further studies are needed to guide the development of criteria and procedures for the initiation and discontinuation of treatment. Furthermore, establishing consensus diagnostic criteria/definitions for THI would improve comparability between studies.

The danger of diazoxide in the neonatal intensive care unit

Background

The most common cause of persistent hypoglycemia in infancy is hyperinsulinemic hypoglycemia. When conservative measures fail, providers often use medications to treat persistent hypoglycemia. Diazoxide is first-line therapy for neonatal hypoglycemia and works by inhibiting insulin secretion. Diazoxide is associated with fluid retention, and less commonly with respiratory decompensation and pulmonary hypertension. Case reports documenting these severe adverse events exist in the literature, although the overall incidence, risk factors, and timing for these effects in a newborn are not clearly defined.

Methods

We performed a retrospective chart review of all infants admitted to the neonatal intensive care unit (NICU) at Regional One Health from 1 January 2013 until 15 August 2019, who received diazoxide as a treatment for persistent hypoglycemia secondary to hyperinsulinism. Patients were stratified as either having no adverse event or having an adverse outcome to the medication. A severe adverse outcome was defined as any known major side effect of the medication, which a patient developed within 2 weeks of medication initiation that led to medication discontinuation.

Results

From our pharmacy database, we identified a total of 15 babies who received diazoxide for persistent hypoglycemia. Of these patients, eight (53%) were classified as having a complication requiring discontinuation of the medication. Six out of eight patients required intubation with mechanical ventilation and five out of eight patients developed pulmonary hypertension. All patients returned to their baseline respiratory support after drug discontinuation.

Conclusions

A total of 53% of our study population had an adverse outcome to diazoxide. Previous studies suggest 5% of patients may have respiratory decompensation and require ventilatory support while on diazoxide; however, 40% of our patients deteriorated and then required mechanical ventilation. Based on our data, respiratory deterioration may be more likely to occur when diazoxide is used in preterm infants, those with lower birth weight and intrauterine growth restriction.

Plain language summary

The dangers in diazoxide Newborns could experience a transient period of low blood glucose levels soon after birth. However, some may progress to persistent low blood glucose levels that cannot be controlled with adequate glucose infusion and may require other ways of treatment. Diazoxide is the first-line drug approved by the US Food and Drug Administration (FDA) for this condition. However, certain cases have reported the development of respiratory deterioration, including increased blood pressure in lung circulation after its use. This prompted a black box warning in 2015 by the FDA. The incidence of neonatal low blood glucose levels seems to have increased and so has the use of this drug. Our study identifies 15 newborns who received diazoxide at Regional One Health neonatal intensive care unit in the past 6 years and reports a significantly higher rate of adverse events in our population leading to drug discontinuation in almost 53% of our cases.

Long-Term Outcome and Treatment in Persistent and Transient Congenital Hyperinsulinism: A Finnish Population-Based Study

CONTEXT

The management of congenital hyperinsulinism (CHI) has improved.

OBJECTIVE

To examine the treatment and long-term outcome of Finnish patients with persistent and transient CHI (P-CHI and T-CHI).

DESIGN

A population-based retrospective study of CHI patients treated from 1972 to 2015.

PATIENTS

106 patients with P-CHI and 132 patients with T-CHI (in total, 42 diagnosed before and 196 after year 2000) with median follow-up durations of 12.5 and 6.2 years, respectively.

MAIN OUTCOME MEASURES

Recovery, diabetes, pancreatic exocrine dysfunction, neurodevelopment.

RESULTS

The overall incidence of CHI (n = 238) was 1:11 300 live births (1972-2015). From 2000 to 2015, the incidence of P-CHI (n = 69) was 1:13 500 and of T-CHI (n = 127) 1:7400 live births. In the 21st century P-CHI group, hyperinsulinemic medication was initiated and normoglycemia achieved faster relative to earlier. Of the 74 medically treated P-CHI patients, 68% had discontinued medication. Thirteen (12%) P-CHI patients had partial pancreatic resection and 19 (18%) underwent near-total pancreatectomy. Of these, 0% and 84% developed diabetes and 23% and 58% had clinical pancreatic exocrine dysfunction, respectively. Mild neurological difficulties (21% vs 16%, respectively) and intellectual disability (9% vs 5%, respectively) were as common in the P-CHI and T-CHI groups. However, the 21st century P-CHI patients had significantly more frequent normal neurodevelopment and significantly more infrequent diabetes and pancreatic exocrine dysfunction compared with those diagnosed earlier.

CONCLUSIONS

Our results demonstrated improved treatment and long-term outcome in the 21st century P-CHI patients relative to earlier.

Comparative meta-analysis of Kabuki syndrome with and without hyperinsulinaemic hypoglycaemia

BACKGROUND AND OBJECTIVE

Kabuki syndrome (KS), caused by pathogenic variants in KMT2D or KDM6A, is associated with hyperinsulinaemic hypoglycaemia (HH) in 0.3%-4% of patients. We characterized the clinical, biochemical and molecular data of children with KS and HH compared to children with KS without HH in a multicentre meta-analysis.

METHODS

Data of seven new and 17 already published children with KS and HH were compared to 373 recently published KS patients without HH regarding molecular and clinical characteristics.

RESULTS

Seven new patients were identified with seven different pathogenic variants in KDM6A (n = 4) or KMT2D (n = 3). All presented with HH on the first day of life and were responsive to diazoxide. KS was diagnosed between 9 months and 14 years of age. In the meta-analysis, 24 KS patients with HH had a significantly higher frequency of variants in KDM6A compared to 373 KS patients without HH (50% vs 11.5%, P < .001), and KDM6A-KS was more likely to be associated with HH than KMT2D-KS (21.8% vs. 3.5%, P < .001). Sex distribution and other phenotypic features did not differ between KS with and without HH.

CONCLUSION

The higher incidence of HH in KDM6A-KS compared to KMT2D-KS indicates that KDM6A loss of function variants predispose more specifically to beta cell dysfunction compared to KMT2D variants. As difficulties to assign syndromic characteristics to KS in early infancy often lead to delayed diagnosis, genetic testing for KS should be considered in children with HH, especially in the presence of other extrapancreatic/syndromic features.

The Incidence and Etiology of Previously Undiagnosed Hypoglycemic Disorders in the Emergency Department

OBJECTIVE

The aim of this study was to determine the incidence and etiology of previously undiagnosed hypoglycemia in children (<18 years of age) seen in a hospital emergency department (ED).

METHODS

A retrospective review of all emergency room visits over a 2-year period was conducted to identify patients younger than 18 years who had hypoglycemia (<50 mg/dL) not associated with a previously known cause. Evaluation of hypoglycemia was conducted during a spontaneous hypoglycemic event or during hypoglycemia induced by a fasting study. Insulin and counter-regulatory hormones were measured simultaneously when the blood glucose was less than 50 mg/dL.

RESULTS

Of 224,125 children seen in the ED during the study, 160 (1:1400) were documented to have hypoglycemia not caused by a previously known condition. Eighty-five (53%) of the 160 hypoglycemic subjects underwent a diagnostic evaluation. Seventeen (20%) of the 85 were classified as having a high-risk disorder causing hypoglycemia, whereas 63 (74%) had a low-risk disorder. Seventy-five patients (47%) did not undergo a diagnostic evaluation during the ED visit or hospital admission.

CONCLUSIONS

Hypoglycemia of unknown etiology occurs in 1:1400 (0.07%) children who attended the ED during the study. Assuming that none of the children who failed to undergo a diagnostic evaluation had a high-risk disorder, 10.6% of the subjects with hypoglycemia were found to have a high-risk disorder. Because of the increased incidence of high-risk disorders causing hypoglycemia and the long-term health risk associated with hypoglycemia, we recommend that all children with hypoglycemia of unknown etiology have a critical blood sample drawn at the time of hypoglycemia (blood glucose <50 mg/dL) or be admitted for a diagnostic evaluation.

Risk Factors for Adverse Neurodevelopment in Transient or Persistent Congenital Hyperinsulinism

OBJECTIVE

Aim was to identify hypotheses why adverse neurodevelopment still occurs in children with transient or persistent hyperinsulinism despite improvements in long-term treatment options during the last decades.

MATERIAL AND METHODS

A retrospective review of 87 children with transient (n=37) or persistent congenital hyperinsulinism (CHI) (n=50) was conducted at the University Children's Hospital Duesseldorf, Germany. Possible risk factors for neurodevelopmental sequelae due to hypoglycemia were analyzed with a focus on the first days after onset of disease.

RESULTS

Median age at follow-up was 7 years (IQR 8). Adverse neurodevelopmental outcome was seen in 34.5% (n=30) of all CHI patients. Fifteen had mildly abnormal neurodevelopment and 15 had a severe hypoglycemic brain injury. In univariate analysis, mildly abnormal neurodevelopment was associated with the diagnosis of persistent CHI (odds ratio (OR) 8.3; p=0.004) and higher birth weight (mean difference 1049 g; p<0.001). Severe hypoglycemic brain injury was associated with the diagnosis of persistent CHI (OR 5.1; p=0.013), being born abroad (OR 18.3; p<0.001) or in a lower-level maternity hospital (OR 4.8; p=0.039), and of note history of hypoglycemic seizures (OR 13.0; p=<0.001), and a delay between first symptoms of hypoglycemia and first blood glucose measurement/initiation of treatment (OR 10.7; p<0.001). Children with severe hypoglycemic brain injury had lower recorded blood glucose (mean difference -8.34 mg/dl; p=0.022) and higher birth weight than children with normal development (mean difference 829 g; p=0.012). In multivariate binary logistic regression models, lowest blood glucose <20 mg/dl (OR 134.3; p=0.004), a delay between initial symptoms and first blood glucose measurement/initiation of treatment (OR 71.7; p=0.017) and hypoglycemic seizures (OR 12.9; p=0.008) were positively correlated with severe brain injury. Analysis showed that the odds for brain injury decreased by 15% (OR 0.85; p=0.035) if the blood glucose increased by one unit.

CONCLUSION

While some risk factors for adverse outcome in CHI are not influenceable, others like lowest recorded blood glucose values <20 mg/dl, hypoglycemic seizures, and insufficiently-or even untreated hypoglycemia can be avoided. Future guidelines for management of neonatal hypoglycemia should address this by ensuring early identification and immediate treatment with appropriate escalation steps.

The screening and management of newborns at risk for low blood glucose

Hypoglycemia in the first hours to days after birth remains one of the most common conditions facing practitioners across Canada who care for newborns. Many cases represent normal physiologic transition to extrauterine life, but another group experiences hypoglycemia of longer duration. This statement addresses key issues for providers of neonatal care, including the definition of hypoglycemia, risk factors, screening protocols, blood glucose levels requiring intervention, and managing care for this condition. Screening, monitoring, and intervention protocols have been revised to better identify, manage, and treat infants who are at risk for persistent, recurrent, or severe hypoglycemia. The role of dextrose gels in raising glucose levels or preventing more persistent hypoglycemia, and precautions to reduce risk for recurrence after leaving hospital, are also addressed. This statement differentiates between approaches to care for hypoglycemia during the 'transitional' phase-the first 72 hours post-birth-and persistent hypoglycemia, which occurs or presents for the first time past that point.

Le dépistage et la prise en charge des nouveau-nés à risque d’hypoglycémie

L’hypoglycémie entre les premières heures et les premiers jours suivant la naissance demeure l’une des principales affections qu’observent les praticiens du Canada qui s’occupent de nouveau-nés. Bien des cas vivent une transition physiologique normale à la vie extra-utérine, mais un groupe présente une hypoglycémie pendant une plus longue période. Le présent document de principes expose les principaux enjeux auxquels sont exposés les dispensateurs de soins néonatals, y compris la définition d’hypoglycémie, les facteurs de risque, les protocoles de dépistage, les valeurs de glycémie nécessitant une intervention et la gestion des soins pour cette affection. Les auteurs passent en revue le dépistage, la surveillance et les protocoles d’intervention pour mieux distinguer, prendre en charge et traiter les nouveau-nés à risque d’hypoglycémie persistante, récurrente ou marquée. Ils abordent également le rôle des gels de dextrose pour accroître la glycémie ou prévenir une hypoglycémie plus persistante, de même que les précautions à prendre pour réduire les risques de récurrence après le congé de l’hôpital. Le présent document de principes distingue les approches des soins de l’hypoglycémie pendant la « phase de transition » (les 72 premières heures de vie) de celles de l’hypoglycémie persistante, qui se manifeste ou est constatée pour la première fois après cette période.

Rate of Serious Adverse Events Associated with Diazoxide Treatment of Patients with Hyperinsulinism

INTRODUCTION

Diazoxide is the first line and only Federal Drug Agency approved pharmacological agent for the treatment of hyperinsulinism. Its use has increased over the years to include patients with various genetic forms of hyperinsulinism, perinatal stress hyperinsulinism and infants of diabetic mothers with more babies than ever being exposed to this therapy.

METHODS

We performed a retrospective analysis of 194 patients with hyperinsulinism in our clinic and looked for those who had experienced serious adverse events (SAE) including pulmonary hypertension and neutropenia. We compared the rates of SAE in the different types of hyperinsulinism.

RESULTS

Out of 194 patients with hyperinsulinism, 165 (85.1%) were treated with diazoxide. There were 17 SAEs in 16 patients including 8 cases of pulmonary hypertension and 8 of neutropenia. These data show that overall the frequency of SAE associated with diazoxide use is 9.7%, but that those with perinatal stress hyperinsulinism have a much higher rate than those with genetic forms of hyperinsulinism (16.7 vs. 3.6%; p = 0.01). We also found diazoxide is associated with pulmonary hypertension (4.8% of patients treated). Although more patients with perinatal stress hyperinsulinism (7.6%) were affected than genetic hyperinsulinism (1.2%), the difference was not significant (p = 0.088).

CONCLUSION

The rate of SAEs associated with (not necessarily caused by) diazoxide has been demonstrated. The rate of SAE in newborns with perinatal stress hyperinsulinism is significantly higher than that of otherwise healthy babies with genetic forms of hyperinsulinism, suggesting that caution should be used when prescribing diazoxide to this population. This information should help balance the risk benefit of treatment and provide guidance on screening for these complications in the population of treated patients.

Clinical characteristics and phenotype-genotype review of 25 Omani children with congenital hyperinsulinism in infancy. A one-decade single-center experience

Objectives:

To report the genotype-phenotype characteristics, demographic features and clinical outcome of Omani patients with congenital hyperinsulinism (CHI).

Methods:

We retrospectively analyzed the clinical, biochemical, genotypical, phenotypical characteristics and outcomes of children with CHI who were presented to the pediatric endocrine team in the Royal Hospital, Muscat, Oman between January 2007 and December 2016.

Results:

Analysis of 25 patients with CHI genetically revealed homozygous mutation in ABCC8 in 23 (92%) patients and 2 patients (8%) with compound heterozygous mutation in ABCC8. Fifteen (60%) patients underwent subtotal pancreatectomy as medical therapy failed and 2 (8%) patients showed response to medical therapy. Three patients expired during the neonatal period, 2 had cardiomyopathy and sepsis, and one had sepsis and severe metabolic acidosis. Out of the 15 patients who underwent pancreatectomy, 6 developed diabetes mellitus, 6 continued to have hypoglycemia and required medical therapy and one had pancreatic exocrine dysfunction post-pancreatectomy, following up with gastroenterology clinic and was placed on pancreatic enzyme supplements, while 2 patients continued to have hypoglycemia and both had abdominal MRI and 18-F-fluoro-L-DOPA positron emission tomography scan (PET-scan), that showed persistent of the disease and started on medical therapy.

Conclusion:

Mutation in ABCC8 is the most common cause of CHI and reflects the early age of presentation. There is a need for early diagnosis and appropriate therapeutic strategy.

The effect of hypoglycaemia on neurocognitive outcome in children and adolescents with transient or persistent congenital hyperinsulinism

AIM

To examine the hypoglycaemic effect on neurodevelopmental outcome in patients with transient and persistent congenital hyperinsulinism (CHI) born in the 21^st century.

METHOD

A cohort of 117 patients (66 males, 51 females) with CHI aged 5 to 16 years (mean age 8y 11mo, SD 2y 7mo) were selected from a Finnish nationwide registry to examine all the patients with similar methods. Neurodevelopment was first evaluated retrospectively. The 83 patients with no risk factors for neurological impairment other than hypoglycaemia were recruited and 44 participated (24 males, 20 females; mean age 9y 7mo, SD 3y 1mo) in neuropsychological assessment with the Wechsler Intelligence Scale for Children, Fourth Edition and the Finnish version of the Developmental Neuropsychological Assessment, Second Edition domains of attention, language, memory, sensorimotor, and visual functioning.

RESULTS

In retrospective analysis, transient and persistent CHI groups had similar prevalences of mild (22% and 18% respectively) or severe (5% and 7% respectively) neurodevelopmental difficulties. In clinical assessment, the neurocognitive profile was within the average range in both groups, but children with persistent CHI showed significant but restricted deficits in attention, memory, visual, and sensorimotor functions compared with the general population. The transient CHI group did not differ from the standardization samples.

INTERPRETATION

Besides the more apparent broader neurological deficits, children with persistent CHI have an increased risk for milder specific neurocognitive problems, which should be considered in the follow-up.

WHAT THIS PAPER ADDS

Children with persistent congenital hyperinsulinism showed deficits in attention, memory, visual, and sensorimotor functions. The deficits were potentially of hypoglycaemic origin. Children with transient hyperinsulinism did not differ from the general population.

Therapies and outcomes of congenital hyperinsulinism-induced hypoglycaemia

Congenital hyperinsulinism is a rare disease, but is the most frequent cause of persistent and severe hypoglycaemia in early childhood. Hypoglycaemia caused by excessive and dysregulated insulin secretion (hyperinsulinism) from disordered pancreatic β cells can often lead to irreversible brain damage with lifelong neurodisability. Although congenital hyperinsulinism has a genetic cause in a significant proportion (40%) of children, often being the result of mutations in the genes encoding the KATP channel (ABCC8 and KCNJ11), not all children have severe and persistent forms of the disease. In approximately half of those without a genetic mutation, hyperinsulinism may resolve, although timescales are unpredictable. From a histopathology perspective, congenital hyperinsulinism is broadly grouped into diffuse and focal forms, with surgical lesionectomy being the preferred choice of treatment in the latter. In contrast, in diffuse congenital hyperinsulinism, medical treatment is the best option if conservative management is safe and effective. In such cases, children receiving treatment with drugs, such as diazoxide and octreotide, should be monitored for side effects and for signs of reduction in disease severity. If hypoglycaemia is not safely managed by medical therapy, subtotal pancreatectomy may be required; however, persistent hypoglycaemia may continue after surgery and diabetes is an inevitable consequence in later life. It is important to recognize the negative cognitive impact of early-life hypoglycaemia which affects half of all children with congenital hyperinsulinism. Treatment options should be individualized to the child/young person with congenital hyperinsulinism, with full discussion regarding efficacy, side effects, outcomes and later life impact.

Characterization of diabetes following pancreatic surgery in patients with congenital hyperinsulinism

Background

Congenital hyperinsulinism (CHI) is the most common cause of persistent hypoglycaemia in infancy that leads to unfavourable neurological outcome if not treated adequately. In patients with severe diffuse CHI it remains under discussion whether pancreatic surgery should be performed or intensive medical treatment with the acceptance of recurrent episodes of mild hypoglycaemia is justified. Near-total pancreatectomy is associated with high rates of insulin-dependent diabetes mellitus and exocrine pancreatic insufficiency. Little is known about the management and long-term glycaemic control of CHI patients with diabetes after pancreatic surgery. We searched the German/Austrian DPV database and compared the course of 42 CHI patients with diabetes to that of patients with type 1 diabetes mellitus (T1DM). Study groups were compared at diabetes onset and after a follow-up period of 6.1 [3.3–9.7] (median [interquartile range]) years.

Results

The majority of CHI patients with diabetes were treated with insulin (85.2% [70.9–99.5] at diabetes onset, and 90.5% [81.2–99.7] at follow-up). However, compared to patients with T1DM, significantly more patients in the CHI group with diabetes were treated with conventional insulin therapy (47.8% vs. 24.4%, p = 0.03 at diabetes onset, and 21.1% vs. 6.4% at follow-up, p = 0.003), and only a small number of CHI patients were treated with insulin pumps. Daily insulin dose was significantly lower in CHI patients with diabetes than in patients with T1DM, both at diabetes onset (0.3 [0.2–0.5] vs. 0.6 IE/kg/d [0.4–0.8], p = 0.003) and follow-up (0.8 [0.4–1.0] vs. 0.9 [0.7–1.0] IE/kg/d, p = 0.02), while daily carbohydrate intake was comparable in both groups. Within the first treatment year, HbA1c levels were significantly lower in CHI patients with diabetes (6.2% [5.5–7.9] vs. 7.2% [6.5–8.2], p = 0.003), but increased to a level comparable to that of T1DM patients at follow-up. Interestingly, in CHI patients, the risk of severe hypoglycaemia tends to be higher only at diabetes onset (14.8% vs. 5.8%, p = 0.1).

Conclusions

In surgically treated CHI patients insulin treatment needs to be intensified in order to achieve good glycaemic control. Our data furthermore emphasize the need for improved medical treatment options for patients with diazoxide- and/or octreotide-unresponsive CHI.

Prevalence of Adverse Events in Children With Congenital Hyperinsulinism Treated With Diazoxide

CONTEXT

Diazoxide, the only U.S. Food and Drug Administration-approved drug to treat hyperinsulinemic hypoglycemia, has been associated with several adverse events, which has raised concerns about the safety of this drug. Existing reports are limited to small studies and case reports.

OBJECTIVE

To determine prevalence of and clinical factors associated with adverse events in infants and children treated with diazoxide.

DESIGN

Retrospective cohort study of children with hyperinsulinism (HI) treated with diazoxide between 2003 and 2014.

SETTING

The Congenital Hyperinsulinism Center at the Children's Hospital of Philadelphia.

PATIENTS

Children and infants with laboratory-confirmed diagnosis of HI.

MAIN OUTCOME MEASURES

Prevalence of pulmonary hypertension (PH), edema, neutropenia, thrombocytopenia, and hyperuricemia was determined. Tests of association and logistic regression were used to identify potential risk factors.

RESULTS

A total of 295 patients (129 female) met inclusion criteria. The median age at diazoxide initiation was 29 days (interquartile range, 10 to 142 days; n = 226 available start dates); 2.4% of patients were diagnosed with PH after diazoxide initiation. Children with PH (P = 0.003) or edema (P = 0.002) were born at earlier gestational age and more frequently had potential PH risk factors, including respiratory failure and structural heart disease (P < 0.0001 and P = 0.005). Other adverse events included neutropenia (15.6%), thrombocytopenia (4.7%), and hyperuricemia (5.0%).

CONCLUSION

In this large cohort, PH occurred in infants with underlying risk factors, but no identifiable risk profile emerged for other adverse events. The relatively high prevalence of neutropenia, thrombocytopenia, and hyperuricemia suggests the value in proactively screening for these side effects in children treated with diazoxide.

The Effect of Continuous Intravenous Glucagon on Glucose Requirements in Infants with Congenital Hyperinsulinism

BACKGROUND/AIMS

Continuous intravenous glucagon is frequently used in the management of severe congenital hyperinsulinism (HI), but its efficacy in these patients has not been systematically evaluated. The aim of this study was to describe the use of continuous intravenous glucagon and to evaluate its effect on the glucose infusion rate (GIR) requirement in infants with HI.

METHODS

Retrospective chart review of children with HI who received continuous intravenous glucagon for prevention of hypoglycemia at the Children's Hospital of Philadelphia between 2003 and 2013.

RESULTS

Forty (22 male) infants were included, and median (IQR) age at glucagon treatment was 29 (23, 54) days. Median glucagon dose was 205 (178, 235) mcg/kg/day and duration of treatment was 5 (3, 9) days. GIR reduced from 18.5 (12.9, 22.8) to 11 (6.6, 17.5) mg/kg/min 24 h after starting glucagon (p < 0.001), and hypoglycemia frequency reduced from 1.9 (1.3, 2.9) to 0.7 (0.3, 1.2) episodes per day. Vomiting (n = 11, 13%), rash (n = 2, 2%), and respiratory distress (n = 15, 19%) were seen during glucagon treatment.

CONCLUSION

An intravenous glucagon infusion reduces the required GIR to maintain euglycemia, decreasing the risks associated with the administration of high fluid volume or fluids with high-glucose concentrations.

Diagnosis and management of hyperinsulinaemic hypoglycaemia

Hyperinsulinaemic hypoglycaemia (HH) is a heterogeneous condition with dysregulated insulin secretion which persists in the presence of low blood glucose levels. It is the most common cause of severe and persistent hypoglycaemia in neonates and children. Recent advances in genetics have linked congenital HH to mutations in 14 different genes that play a key role in regulating insulin secretion (ABCC8, KCNJ11, GLUD1, GCK, HADH, SLC16A1, UCP2, HNF4A, HNF1A, HK1, PGM1, PPM2, CACNA1D, FOXA2). Histologically, congenital HH can be divided into 3 types: diffuse, focal and atypical. Due to the biochemical basis of this condition, it is essential to diagnose and treat HH promptly in order to avoid the irreversible hypoglycaemic brain damage. Recent advances in the field of HH include new rapid molecular genetic testing, novel imaging methods (18F-DOPA PET/CT), novel medical therapy (long-acting octreotide formulations, mTOR inhibitors, GLP-1 receptor antagonists) and surgical approach (laparoscopic surgery). The review article summarizes the current diagnostic methods and management strategies for HH in children.

Challenging diagnosis of congenital hyperinsulinism in two infants of diabetic mothers with rare pathogenic KCNJ11 and HNF4A gene variants

Background

Congenital hyperinsulinism (CHI) is the leading cause of persistent hypoglycemia in infants. The infants of diabetic mothers (IDMs) very frequently present with neonatal hypoglycemia associated to transient hyperinsulinism however the incidence of CHI in IDMs is unknown.

Case presentation

Here we report 2 cases of CHI where the diagnoses were challenged and delayed because both patients were infants of diabetic mothers (IDMs) and had concomitant complicated medical conditions. Case 1 was heterozygous for a likely pathogenic variant in KCNJ11(p.Arg206Cys), and Case 2 was heterozygous for a pathogenic HNF4A variant, (p.Arg267Cys). HNF4A-associated CHI is very rare, and this particular case had a clinical phenotype quite different from that of previously described HNF4A-CHI cases.

Conclusions

This case series is one of few reports in the medical literature describing two IDMs with persistent recurrent hypoglycemia secondary to CHI, and a different clinical phenotype for HNF4A-associated CHI. IDMs typically present with transient hyperinsulinism lasting no more than 2–3 days. Since being an IDM does not exclude CHI, this diagnosis should always be considered as the mostly likely etiology if neonatal hypoglycemia persists longer than the described time frame and genetic testing for CHI confirmation is highly suggested.

The burden of congenital hyperinsulinism in the United Kingdom: a cost of illness study

BACKGROUND

Congenital hyperinsulinism (CHI) is a rare, genetic disease which causes persistent hypoglycaemia, typically in new-borns. Patients with the diffuse disease variant often require near-total surgical removal of the pancreas, causing insulin-dependent diabetes mellitus (IDDM). The CHI economic burden is currently unknown. This study aimed to estimate the annual cost of illness (COI) of CHI patients in the UK from a service provider perspective (National Health Service, NHS and Personal Social Services), and to explore cost distribution within the patient population.

METHODS

The model was based on standard practice of two CHI centres of excellence. Model inputs were informed by a pragmatic literature review, NHS Reference Costs (2015-2016) and the British National Formulary (2017). Only direct costs to the NHS and Personal Social Services were considered. A prevalence-based approach was used and annual costs incurred at all ages were calculated. A deterministic sensitivity analysis (DSA; run at 10%) identified major cost drivers.

RESULTS

The COI of CHI patients to the NHS was £3,408,398.59 annually and average cost per patient was £2124.95. Cost distribution was skewed among CHI patients, with 5.9% of patients (95 patients in their first year of life) contributing to 61.8% (£2,105,491.07) of total costs. DSA results identified lack of response to first-line therapy and IDDM development post surgery (and associated healthcare costs) as major cost drivers.

CONCLUSIONS

Despite its rare disease status, estimated annual costs of CHI to the NHS were substantial. Development and management of post-surgical IDDM as a major cost driver highlights the need for effective treatments to mitigate such consequences and costs.

Hyperinsulinemic hypoglycemia: clinical, molecular and therapeutical novelties

Hyperinsulinemic hypoglycemia (HI) is the most common cause of hypoglycemia in children. Impairment of cellular pathways involved in insulin secretion from pancreatic β-cells, broadly classified as channelopathies and metabolopathies, have been discovered in the past two decades. The increasing use of NGS target panels, combined with clinical, biochemical and imaging findings allows differentiating the diagnostic management of children with focal forms, surgically curable, from those with diffuse forms, more conservatively treated with pharmacological and nutritional interventions. Specific approaches according to the subtype of HI have been established and novel therapies are currently under investigation. Despite diagnostic and therapeutic advances, HI remains an important cause of morbidity in children, still accounting for 26-44% of permanent intellectual disabilities, especially in neonatal-onset patients. Initial insult from recurrent hypoglycemia in early life greatly contributes to the poor outcomes. Therefore, patients need to be rapidly identified and treated aggressively, and require at follow-up a complex and regular monitoring, managed by a multidisciplinary HI team. This review gives an overview on the more recent diagnostic and therapeutic tools, on the novel drug and nutritional therapies, and on the long-term neurological outcomes.

Congenital Hypoglycemia Disorders: New Aspects of Etiology, Diagnosis, Treatment and Outcomes: Highlights of the Proceedings of the Congenital Hypoglycemia Disorders Symposium, Philadelphia April 2016

Hypoglycemia continues to be an important cause of morbidity in neonates and children. Prompt diagnosis and management of the underlying hypoglycemia disorder is critical for preventing brain damage and improving outcomes. Congenital hyperinsulinism (HI) is the most common and severe cause of persistent hypoglycemia in neonates and children. Recent discoveries of the genetic causes of HI have improved our understanding of the pathophysiology, but its management is complex and requires the integration of clinical, biochemical, molecular, and imaging findings to establish the appropriate treatment according to the subtype. Here we present a summary of a recent international symposium on congenital hypoglycemia disorders with emphasis on novel molecular mechanisms resulting in HI, genetic diagnosis, overall approach to management, novel therapies under development, and current outcomes.

Both Low Blood Glucose and Insufficient Treatment Confer Risk of Neurodevelopmental Impairment in Congenital Hyperinsulinism: A Multinational Cohort Study

BACKGROUND/AIMS

Congenital hyperinsulinism (CHI) is a heterogeneous disease most frequently caused by KATP-channel (ABCC8 and KCNJ11) mutations, with neonatal or later onset, variable severity, and with focal or diffuse pancreatic involvement as the two major histological types. CHI confers a high risk of neurological impairment; however, sparsely studied in larger patient series. We assessed the neurodevelopmental outcome in children with CHI at follow-up in a mixed international cohort.

METHODS

In two hyperinsulinism expert centers, 75 CHI patients were included (Russian, n = 33, referred non-Scandinavian, treated in Denmark n = 27, Scandinavian, n = 15). Hospital files were reviewed. At follow-up, neurodevelopmental impairment and neurodevelopmental, cognitive and motor function scores were assessed.

RESULTS

Median (range) age at follow-up was 3.7 years (3.3 months-18.2 years). Neurodevelopmental impairment was seen in 35 (47%). Impairment was associated with abnormal brain magnetic resonance imaging (MRI); odds ratio (OR) (95% CI) 15.0 (3.0-74.3), p = 0.001; lowest recorded blood glucose ≤1 mmol/L; OR 3.8 (1.3-11.3), p = 0.015, being non-Scandinavian patient, OR 3.8 (1.2-11.9), p = 0.023; and treatment delay from first symptom to expert center >5 days; OR 4.0 (1.0-16.6), trend p = 0.05. In multivariate analysis (n = 31) for early predictors with exclusion of brain MRI, treatment delay from first symptom to expert center >5 days conferred a significantly increased risk of neurodevelopment impairment, adjusted OR (aOR) 15.6 (1.6-146.7), p = 0.016, while lowest blood glucose ≤1 mmol/L had a trend toward increased risk, aOR 3.5 (1.1-14.3), p = 0.058. No associations for early vs. late disease onset, K_ATP-channel mutations, disease severity, focal vs. diffuse disease, or age at follow-up were seen in uni- or multivariate analysis.

CONCLUSION

Not only very low blood glucose, but also insufficient treatment as expressed by delay until expert center hospitalization, increased the risk of neurodevelopmental impairment. This novel finding calls for improvements in spread of knowledge about CHI among health-care personnel and rapid contact with an expert CHI center on suspicion of CHI.

Genetic characteristics and long-term follow-up of 11 patients with congenital hyperinsulinism followed in a single center

BACKGROUND

Congenital hyperinsulinism (CHI) is a rare disease with an estimated incidence of 1:40,000 live births. Here, we characterize 11 patients treated at Munich Children's Hospital Schwabing.

METHODS

We analyzed data on birth, treatment and laboratory results including genetic testing and evaluated the long-term course with a follow-up visit.

RESULTS

All patients had severe, diazoxide-(DZX)-resistant hypoglycemia, beginning immediately after birth. Two patients were treated by medical therapy, eight underwent subtotal pancreatectomy and one had a partial resection. Both patients who had medical therapy still suffer from occasional hypoglycemia. Six patients with subtotal pancreatectomy were affected by mild hypoglycemia. Seventy-five percent of patients who had surgical treatment developed diabetes mellitus (DM) at a median age of 10.5 (8-13) years. In 89% of patients with available genetic testing, mutations of the ABCC8 gene were detected.

CONCLUSIONS

The majority of CHI-patients not responding to DZX underwent surgery. After subtotal pancreatectomy, patients typically developed diabetes around early puberty.

Perspective on the Genetics and Diagnosis of Congenital Hyperinsulinism Disorders

CONTEXT

Congenital hyperinsulinism (HI) is the most common cause of hypoglycemia in children. The risk of permanent brain injury in infants with HI continues to be as high as 25-50% due to delays in diagnosis and inadequate treatment. Congenital HI has been described since the birth of the JCEM under various terms, including "idiopathic hypoglycemia of infancy," "leucine-sensitive hypoglycemia," or "nesidioblastosis."

EVIDENCE ACQUISITION

In the past 20 years, it has become apparent that HI is caused by genetic defects in the pathways that regulate pancreatic β-cell insulin secretion.

EVIDENCE SYNTHESIS

There are now 11 genes associated with monogenic forms of HI (ABCC8, KCNJ11, GLUD1, GCK, HADH1, UCP2, MCT1, HNF4A, HNF1A, HK1, PGM1), as well as several syndromic genetic forms of HI (eg, Beckwith-Wiedemann, Kabuki, and Turner syndromes). HI is also the cause of hypoglycemia in transitional neonatal hypoglycemia and in persistent hypoglycemia in various groups of high-risk neonates (such as birth asphyxia, small for gestational age birthweight, infant of diabetic mother). Management of HI is one of the most difficult problems faced by pediatric endocrinologists and frequently requires difficult choices, such as near-total pancreatectomy and/or highly intensive care with continuous tube feedings. For 50 years, diazoxide, a KATP channel agonist, has been the primary drug for infants with HI; however, it is ineffective in most cases with mutations of ABCC8 or KCNJ11, which constitute the majority of infants with monogenic HI.

CONCLUSIONS

Genetic mutation testing has become standard of care for infants with HI and has proven to be useful not only in projecting prognosis and family counseling, but also in diagnosing infants with surgically curable focal HI lesions. (18)F-fluoro-L-dihydroxyphenylalanine ((18)F-DOPA) PET scans have been found to be highly accurate for localizing such focal lesions preoperatively. New drugs under investigation provide hope for improving the outcomes of children with HI.

Postoperative Hyperglycemia and 4-Year Neurodevelopmental Outcome in Children Operated for Congenital Heart Disease

OBJECTIVES

To study the long-term neurodevelopmental effects of hyperglycemia in infant bypass surgery for congenital heart disease (CHD).

STUDY DESIGN

Prospective cohort study on neurodevelopmental outcome after infant cardiac bypass surgery.

EXCLUSION CRITERIA

age older than 1 year at first surgery, genetic comorbidity, and birth weight <2000 g. Of 167 eligible infants, follow-up examination at 4 years was completed in 150 children (90%). Intraoperative and postoperative highest and lowest glucose levels within 24 hours after bypass surgery were prospectively collected. Neurodevelopmental outcome at 4 years of age was assessed using standardized IQ tests and the Movement Assessment Battery for Children-second version for motor outcome assessment.

RESULTS

Mean age at surgery was 2.8 months (0.1-10.7 months), 33% of children had an acyanotic CHD and 67% a cyanotic CHD. Glucose levels were elevated (>8 mmol/L) in 21 (14%) children in the first 24 postoperative hours. Glucose levels normalized in all children within 48 hours, 7 children (4%) received insulin infusions. Mean total IQ was within the normal range, but significantly lower than the normal population (92.5 [SD 15.0], P < .001). Higher postoperative glucose levels were related to better cognitive performance in the univariate analysis (P < .03), but not when other risk factors were taken into account. Independent risk factors for adverse outcome were lower socioeconomic status, higher risk adjustment for congenital heart surgery score, and longer duration of intensive care stay.

CONCLUSION

Hyperglycemia is common in the early postoperative course after infant bypass surgery for CHD and normalizes within 48 hours. Hyperglycemia has no adverse effect on long-term neurodevelopmental outcome.

High Risk of Diabetes and Neurobehavioral Deficits in Individuals With Surgically Treated Hyperinsulinism

CONTEXT

Children with the most common and severe type of congenital hyperinsulinism (HI) frequently require pancreatectomy to control the hypoglycemia. Pancreatectomy increases the risk for diabetes, whereas recurrent hypoglycemia places children at risk of neurocognitive dysfunction. The prevalence of these complications is not well defined.

OBJECTIVE

The objective was to determine the prevalence of diabetes and neurobehavioral deficits in surgically treated HI.

DESIGN

This was designed as a cross-sectional study of individuals who underwent pancreatectomy for HI between 1960 and 2008.

OUTCOMES

Diabetes outcomes were assessed through patient interview and medical record review. Neurobehavioral outcomes were assessed through the Adaptive Behavior Assessment System, 2nd edition (ABAS-II), and the Child Behavior Checklist (CBCL).

RESULTS

A total of 121 subjects were enrolled in the study at a median age of 8.9 years (range, 3.5-50.7 y). Thirty-six percent (44 of 121) of subjects had diabetes. Nine subjects developed diabetes immediately after pancreatectomy. Of the remaining 35 subjects who developed diabetes, the median age at diabetes diagnosis was 7.7 years (range, 8 mo to 43 y). In subjects with diabetes, the median hemoglobin A1c was 7.4% (range, 6.5-12.6%), and 38 (86%) subjects required insulin. Subjects with diabetes had a greater percentage of pancreatectomy than subjects without diabetes (95% [range, 65-98] vs 65% [1-98]). Neurobehavioral abnormalities were reported in 58 (48%) subjects. Nineteen (28%) subjects had abnormal ABAS-II scores, and 10 (16%) subjects had abnormal CBCL scores.

CONCLUSIONS

Children, who undergo near-total pancreatectomy are at high risk of developing diabetes. Neurobehavioral deficits are common, and developmental assessment is essential for children with HI.

A compound heterozygous mutation of ABCC8 gene causing a diazoxide-unresponsive congenital hyperinsulinism with an atypical form: Not a focal lesion in the pancreas reported by ¹⁸F-DOPA-PET/CT scan

Congenital hyperinsulinism (CHI) is a severe heterogeneous disorder due to dysregulation of insulin secretion from the pancreatic β-cells leading to severe hypoglycemia in infancy. 18-fluoro-l-3,4-dihydroxyphenylalanine positron emission tomography ((18)F‑DOPA‑PET)/CT is a useful tool in distinguishing between focal and diffuse disease preoperatively. But recent studies have suggested that the scanning may not be accurate as initially estimated. In this study we characterize a case of CHI with a compound heterozygous mutation of ABCC8 gene. The results of clinical investigation, gene mutation analysis, (18)F‑DOPA‑PET/CT scan, and pathological examination showed some new characteristics that have never been reported. The patient was unresponsive to medical therapy with diazoxide and received pancreatectomy twice. Genetic analysis identified a compound heterozygous mutation in ABCC8 genes. Imaging with (18)F‑DOPA‑PET/CT indicated a focal lesion in the head of the pancreas. The pathological diagnosis was an atypical form of CHI. The patient presented with a phenotype of atypical CHI unresponsive to diazoxide. It is considered that a relationship existed between the compound heterozygous mutation and the atypical form. (18)F‑DOPA‑PET/CT is a useful tool in distinguishing between focal and diffuse forms preoperatively but the accuracy is not 100%. The scan result is best combined with genetic analysis and intra-operative biopsy to confirm the histological subtypes. The combination will provide the optimal strategy for the surgical treatment of patients with CHI.

Congenital hyperinsulinism: exclusive human milk and breastfeeding

Congenital hyperinsulinism is a genetic condition causing dysregulation of insulin and results in persistent hypoglycemia. The most common types are sulfonylurea receptor (SUR1), potassium inward rectifying channel (Kir6.2), glutamate dehydrogenase (GDH), and glucokinase (GK), with SUR1 and Kir6.2 being the most prevalent. It is imperative that these infants undergo diagnostic testing, which includes genetic, neonatal fasting study to induce hypoglycemia, glucagon stimulation, and imaging. Once a diagnosis has been made, surgical intervention may be needed to help regulate blood glucose levels. During this diagnostic process and as the infant is undergoing treatment, there may be little concern for the mother's feeding plan. Because human milk is the preferred form of nutrition for all infants, these mothers should receive prenatal counseling regarding the initiation and maintenance of milk supply. Parenteral nutrition may be necessary to maintain blood glucose to support human milk administration and breastfeeding.

Congenital hyperinsulinism: global and Japanese perspectives

Over the past 20 years, there has been remarkable progress in the diagnosis and treatment of congenital hyperinsulinism (CHI). These advances have been supported by the understanding of the molecular mechanism and the development of diagnostic modalities to identify the focal form of ATP-sensitive potassium channel CHI. Many patients with diazoxide-unresponsive focal CHI have been cured by partial pancreatectomy without developing postsurgical diabetes mellitus. Important novel findings on the genetic basis of the other forms of CHI have also been obtained, and several novel medical treatments have been explored. However, the management of patients with CHI is still far from ideal. First, state-of-the-art treatment is not widely available worldwide. Second, it appears that the management strategy needs to be adjusted according to the patient's ethnic group. Third, optimal management of patients with the diazoxide-unresponsive, diffuse form of CHI is still insufficient and requires further improvement. In this review, we describe the current landscape of this disorder, discuss the racial disparity of CHI using Japanese patients as an example, and briefly note unanswered questions and unmet needs that should be addressed in the near future.

Management strategies for neonatal hypoglycemia

While hypoglycemia occurs commonly among neonates, treatment can be challenging if hypoglycemia persists beyond the first few days of life. This review discusses the available treatment options for both transient and persistent neonatal hypoglycemia. These treatment options include dextrose infusions, glucagon, glucocorticoids, diazoxide, octreotide, and nifedipine. A stepwise, practical approach to the management of these patients is offered.

Congenital hyperinsulinism: current status and future perspectives

The diagnosis and treatment of congenital hyperinsulinism (CHI) have made a remarkable progress over the past 20 years and, currently, it is relatively rare to see patients who are left with severe psychomotor delay. The improvement was made possible by the recent developments in the understanding of the molecular and pathological basis of CHI. Known etiologies include inactivating mutations of the KATP channel genes (ABCC8 and KCNJ11) and HNF4A, HNF1A, HADH, and UCP2 or activating mutations of GLUD1, GCK, and SLC16A1. The understanding of the focal form of KATP channel CHI and its detection by (18)F-fluoro-L-DOPA positron emission tomography have revolutionized the management of CHI, and many patients can be cured without postoperative diabetes mellitus. The incidence of the focal form appears to be higher in Asian countries; therefore, the establishment of treatment systems is even more important in this population. In addition to diazoxide or long-term subcutaneous infusion of octreotide or glucagon, long-acting octreotide or lanreotide have also been used successfully until spontaneous remission. Because of these medications, near-total pancreatectomy is less often performed even for the diazoxide-unresponsive diffuse form of CHI. Other promising medications include pasireotide, small-molecule correctors such as sulfonylurea or carbamazepine, GLP1 receptor antagonists, or mammalian target of rapamycin inhibitors. Unsolved questions in this field include the identification of the remaining genes responsible for CHI, the mechanisms leading to transient CHI, and the mechanisms responsible for the spontaneous remission of CHI. This article reviews recent developments and hypothesis regarding these questions.

Investigation and management of congenital hyperinsulinism

Insulin is a powerful hormone produced by the beta-cells in the pancreas. Its major function is to regulate blood glucose levels, facilitating the transport of glucose into the body's cells. Congenital hyperinsulinism is characterized by the presence of insulin that is inappropriately high for the concentration of blood glucose. Because high levels of insulin also switch off all alternative fuels for the brain to use, this condition can cause brain injury if not detected quickly. Nurses are in a unique position by the bedside to identify the symptoms and treat the hypoglycaemia through very simple nursing interventions, such as safe administration of glucose and frequent blood glucose monitoring. Congenital hyperinsulinism can be transient or persistent. Persistent congenital hyperinsulinism can be further divided into focal or diffuse disease. Focal congenital hyperinsulinism can now be cured, and the management of congenital hyperinsulinism has radically changed with the help of genetics and research. Now pancreatectomy surgery is only used as the last resort.

Persistent hyperinsulinemic hypoglycemia with left ventricular hypertrophy and dysrhythmia: a case report

Persistent hyperinsulinemic hypoglycemia in neonatal period is characterized by insulin hypersecretion. The major feature is severe hypoglycemia, generally unresponsive to routine medical treatment. Subtotal or total pancreatectomy is performed in unresponsive cases. In this case report, we present a newborn with persistent hypoglycemia unresponsive to medical treatment with dysrhythmic left ventricular hypertrophy. The insulin/C-peptide ratio was 58 as a confirmation of diagnosis. Since hypoglycemia persisted after the initial medical treatment, a subtotal pancreatectomy was performed followed by near-total pancreatectomy. A histologic examination revealed diffuse insulin islets. At the 70th post-natal day, death occurred due to heart failure and ventricular dysrhythmia. To our knowledge, severe dysrhythmia and left ventricular hypertrophy in persistent hyperinsulinemic hypoglycemia (PPH) is identified in the patient.

Fluorine-18 DOPA-PET and PET/CT Imaging in Congenital Hyperinsulinism

Congenital hyperinsulinism is the principle cause of hypoglycemia during infancy but successful treatment is difficult and persistent hypoglycemia carries the risk of neurologic damage. Focal and diffuse abnormalities are the common forms of hyperinsulinism. Identification and localization of focal hyperinsulinism can be cured by partial pancreatectomy. It has been shown that affected pancreatic areas utilize LDOPA in a higher rate than normal pancreatic tissue and, thus, labeling L-DOPA with fluorine-18 (FDOPA) allows functional mapping of hyperinsulinism using PET. This article presents a fundamental overview of the genetics background, pathology, management, and the role of FDOPA-PET imaging in hyperinsulinism.

Neurologic sequelae of neonatal hypoglycemia in Kayseri, Turkey

Contrary to belief, neonatal hypoglycemia is relatively common and can cause more severe neurological sequelae than is currently believed. Prevention of hypoglycemic brain damage by hindering prolonged and profound neonatal hypoglycemia might contribute to psychomotor development. At Erciyes University, between December 1996 and 2005, of the patients who applied to Paediatric Neurology Department, 60 cases with a history of neonatal hypoglycemia were included in the study. The magnetic resonance imaging (MRI) scans and clinical records of all patients were reviewed retrospectively. It was noted that the sequelae with glucose levels of 0 0 to 40 were more serious and intense. The same results were also observed in cranial MRI evaluation. In conclusion, intractable epilepsy, mental motor retardation, cerebral palsy, and visual disturbance were found to be the most common and severe conditions affecting sufferers of neonatal hypoglycemia. In the first 3 days of life, the close monitoring of patients at risk is critical, and hospitalization of severe cases should be considered.

Glycemic profile in infants who have undergone the arterial switch operation: hyperglycemia is not associated with adverse events

OBJECTIVE

Tight glycemic control improves outcomes in critically ill adults. There are limited data regarding the effect of glycemic profiles in infants after cardiac operations. The aim of this study was to evaluate the association of hyperglycemia and hypoglycemia on adverse events in infants undergoing the arterial switch operation.

METHODS

From 2000 through 2005, 93 infants underwent the arterial switch operation (mean age, 2.5 +/- 5.9 weeks; mean weight, 3.4 +/- 0.8 kg). All serum glucose values during the first 24 postoperative hours were documented. The effect of time spent in specific glycemic bands on adverse events was determined.

RESULTS

Twenty-three (25%; group 1) infants spent more than 50% of the time with glucose values between 80 and 110 mg/dL, and 13 (14%; group 2) spent more than 50% of the time with glucose values of greater than 200 mg/dL. A total of 71 adverse events was documented in 45 (48%) of 93 infants. Group 1 infants were more likely to have any adverse event (P = .001) and renal insufficiency (P < .001). Group 2 infants were not more likely to have adverse events. When controlling for preoperative and operative factors, being in group 1 was an independent predictor of postoperative adverse events (P = .004).

CONCLUSION

Hyperglycemia does not appear to be detrimental in postoperative infants with congenital heart disease. Infants who spent the majority of the time with glucose values between 80 and 110 mg/dL were at increased risk for adverse events. The ideal glycemic profile in the postoperative cardiac infant has yet to be defined.

Hyperinsulinism in Infancy and Childhood: When an Insulin Level Is Not Always Enough

Background: Hypoglycemia in infants and children can lead to seizures, developmental delay, and permanent brain damage. Hyperinsulinism (HI) is the most common cause of both transient and permanent disorders of hypoglycemia. HI is characterized by dysregulated insulin secretion, which results in persistent mild to severe hypoglycemia. The various forms of HI represent a group of clinically, genetically, and morphologically heterogeneous disorders.

Content: Congenital hyperinsulinism is associated with mutations of SUR-1 and Kir6.2, glucokinase, glutamate dehydrogenase, short-chain 3-hydroxyacyl-CoA dehydrogenase, and ectopic expression on β-cell plasma membrane of SLC16A1. Hyperinsulinism can be associated with perinatal stress such as birth asphyxia, maternal toxemia, prematurity, or intrauterine growth retardation, resulting in prolonged neonatal hypoglycemia. Mimickers of hyperinsulinism include neonatal panhypopituitarism, drug-induced hypoglycemia, insulinoma, antiinsulin and insulin-receptor stimulating antibodies, Beckwith-Wiedemann Syndrome, and congenital disorders of glycosylation. Laboratory testing for hyperinsulinism may include quantification of blood glucose, plasma insulin, plasma β-hydroxybutyrate, plasma fatty acids, plasma ammonia, plasma acylcarnitine profile, and urine organic acids. Genetic testing is available through commercial laboratories for genes known to be associated with hyperinsulinism. Acute insulin response (AIR) tests are useful in phenotypic characterization. Imaging and histologic tools are also available for diagnosing and classifying hyperinsulinism. The goal of treatment in infants with hyperinsulinism is to prevent brain damage from hypoglycemia by maintaining plasma glucose levels above 700 mg/L (70 mg/dL) through pharmacologic or surgical therapy.

Summary: The management of hyperinsulinism requires a multidisciplinary approach that includes pediatric endocrinologists, radiologists, surgeons, and pathologists who are trained in diagnosing, identifying, and treating hyperinsulinism.

Congenital hyperinsulinism in an infant caused by a macroscopic insulin-producing lesion

Congenital hyperinsulinism is the most common cause of persistent neonatal hypoglycemia. Severe congenital hyperinsulinism is most often due to inactivating mutations in either the ABCC8 or KCNJ11 genes, which encode the SUR1 and Kir6.2 proteins, respectively--the two components of the ATP-sensitive K+ (KATP) channel; neonatal hypoglycemia due to macroscopic insulin-producing pancreatic lesions or adenomas are extremely rare. KATP channel hyperinsulinism is classified as diffuse or focal, the latter being associated with paternally-derived mutations of ABCC8 or KCNJ11 and somatic loss of heterozygosity of the maternal alleles. KATP channelopathies usually produce microscopic intra-pancreatic lesions and are typically unresponsive to drug therapy, requiring > 95% pancreatectomy for diffuse disease and occasionally more limited pancreatic resection for focal disease; macroscopic pancreatic lesions and adenomas are focally excised. We describe a 1 month-old infant with severe congenital hyperinsulinism who had a macroscopic insulin-producing pancreatic lesion successfully treated with focal lesion enucleation.