Idiopathic pathological ketotic hypoglycemia: finding the needle in a haystack.

Sick children often have a decreased appetite and experience vomiting and diarrhea; however, hypoglycemia (plasma glucose concentration ≤50 mg/dL or 2.8 mmol/L) is rare. Ketotic hypoglycemia (KH) is the most common cause of hypoglycemia presenting to an Emergency Department in a previously healthy child between 6 months and 6 years of age. Ketosis and hypoglycemia are now well understood to be normal physiologic responses of young children to prolonged fasting. There is now substantial evidence that the term KH describes a variety of conditions including both the lower end of the normal distribution of fasting tolerance in young children as well as numerous rare disorders that impair fasting adaptation. Recent advances in molecular genetic testing have led to the discovery of these rare disorders. Idiopathic pathological KH is a diagnosis of exclusion that describes rare children who have abnormally limited fasting tolerance, experience recurrent episodes of KH, or develop symptoms of hypoglycemia despite elevated ketone levels, and in whom an explanation cannot be found despite extensive investigation. This review provides an approach to distinguishing between physiological KH and pathological KH and includes recommendations for management.

Approach to the Patient: Investigation of pediatric hypoglycemia in the emergency department - a practical algorithm.

Hypoglycemia in the pediatric population tends to present in the newborn period or during metabolic crisis triggered by prolonged fasting and intercurrent illness. Current recommendations to investigate all children presenting with hypoglycemia for the first time are cumbersome and costly, but necessary to identify those with serious conditions that predispose to hypoglycemia. We describe a practical and cost-effective method of evaluating children who present to the emergency department with previously undiagnosed hypoglycemia. Glucose and point-of-care (POC) beta-hydroxybutyrate (G-BOHB) levels should be measured on all children with a low screening POC glucose levels, and a full history and physical examination will identify those requiring further investigation. This approach is suggested to identify patients with serious and life-threatening disease with the same fidelity as the currently recommended approach of performing a critical sample on all children with hypoglycemia. Our streamlined approach will reduce the cost to approximately 10% of the current approach per patient diagnosed with a serious underlying disease. Further, children without underlying hypoglycemia-predisposing disorders will be identified and discharged without unnecessary intervention.

Dasiglucagon for the Treatment of Congenital Hyperinsulinism: A Randomized Phase 3 Trial in Infants and Children.

CONTEXT: Congenital hyperinsulinism (CHI) is characterized by dysregulated insulin secretion causing hypoglycemia and consequent brain damage. Dasiglucagon is a glucagon analogue under investigation to treat CHI. OBJECTIVE: To evaluate the efficacy and safety of dasiglucagon delivered via continuous subcutaneous infusion to children with CHI and persistent hypoglycemia as add-on to standard of care (SoC). METHODS: In this open-label trial, patients were randomized 1:1 to SoC or SoC + dasiglucagon (10-70 µg/h) for 4 weeks. In the following 4 weeks, all patients received dasiglucagon + SoC. Hypoglycemia was assessed by self-monitored plasma glucose (SMPG) and blinded continuous glucose monitoring (CGM). Primary endpoint was average number of SMPG-detected hypoglycemia episodes/week (SMPG <3.9 mmol/L) during Weeks 2 to 4. RESULTS: Thirty-two patients (0.6-10.9 years) were randomly assigned to dasiglucagon + SoC (n = 16) or SoC (n = 16). The rate of SMPG-detected hypoglycemia decreased from baseline in both groups, but with no statistically significant difference during Weeks 2 to 4 (event rate ratio: 0.85 [0.54; 1.36], P = .5028). However, dasiglucagon administration resulted in a 43% reduction in CGM-detected hypoglycemia (<3.9 mmol/L) vs SoC alone during Weeks 2 to 4 (post hoc analysis; event rate ratio: 0.57 [0.39; 0.83], P = .0029). Dasiglucagon enabled reductions (of 37% to 61%) in all other measures of hypoglycemia assessed by CGM vs SoC alone including extent and percent time in hypoglycemia (post hoc analyses). Dasiglucagon appeared safe and well tolerated. Skin and gastrointestinal events were more frequent with dasiglucagon + SoC than SoC only. CONCLUSION: Clinically meaningful reductions in all CGM-recorded measures of hypoglycemia support using dasiglucagon as a potential treatment for CHI.

International Guidelines for the Diagnosis and Management of Hyperinsulinism.

Hyperinsulinism (HI) due to dysregulation of pancreatic beta-cell insulin secretion is the most common and most severe cause of persistent hypoglycemia in infants and children. In the 65 years since HI in children was first described, there has been a dramatic advancement in the diagnostic tools available, including new genetic techniques and novel radiologic imaging for focal HI, however; there have been almost no new therapeutic modalities since the development of diazoxide. Recent advances in neonatal research and genetics have improved our understanding of the pathophysiology of both transient and persistent forms of neonatal hyperinsulinism. Rapid turnaround of genetic test results combined with advanced radiologic imaging can permit identification and localization of surgically-curable focal lesions in a large proportion of children with congenital forms of HI, but are only available in certain centers in 'developed' countries. Diazoxide, the only drug currently approved for treating HI, was recently designated as an "essential medicine" by the World Health Organization but has been approved in only 16% of Latin American countries and remains unavailable in many under-developed areas of the world. Novel treatments for HI are emerging, but they await completion of safety and efficacy trials before being considered for clinical use. This international consensus statement on diagnosis and management of HI was developed in order to assist specialists, general pediatricians, and neonatologists in early recognition and treatment of HI with the ultimate aim of reducing the prevalence of brain injury caused by hypoglycemia. A previous statement on diagnosis and management of HI in Japan was published in 2017. The current document provides an updated guideline for management of infants and children with HI and includes potential accommodations for less-developed regions of the world where resources may be limited.

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.

Congenital Hyperinsulinism: An Historical Perspective.

Congenital hyperinsulinism is the most common cause of persistent hypoglycemia in neonates, infants, and children. Since the first case descriptions in the 1950s, the field has advanced significantly. It was the development of the insulin radioimmunoassay by Yalow and Berson a decade later that made it possible to demonstrate that this form of persistent hypoglycemia was caused by insulin, and a few years later, Drash described the successful treatment of children with hyperinsulinism with the antihypertensive diazoxide, which until today remains the only approved treatment for hyperinsulinism. In the mid 1970s, Baker and Stanley described that hyperinsulinism can be recognized by inappropriate responses of metabolic fuels and hormones during the course of a provocative fasting challenge. Later, advances in molecular genetics led to the discovery of the different genetic subtypes of hyperinsulinism. One of the most impactful discoveries in the field was the recognition of the focal form of hyperinsulinism and the development of 18F-DOPA PET for the localization of focal lesions before surgery which has resulted in the possibility of cure for children with focal disease. However, treatment options for children with nonfocal diazoxide-unresponsive hyperinsulinism have continued to be limited. New drug development programs for hyperinsulinism promise to change this in the next few years. Unfortunately, despite all these advances, children with hyperinsulinism around the world continue to experience neurological sequelae at high rates, highlighting the importance of early diagnosis and effective treatment.

Hyperinsulinemic Hypoglycemia Associated with a CaV1.2 Variant with Mixed Gain- and Loss-of-Function Effects.

The voltage-dependent L-type calcium channel isoform CaV1.2 is critically involved in many physiological processes, e.g., in cardiac action potential formation, electromechanical coupling and regulation of insulin secretion by beta cells. Gain-of-function mutations in the calcium voltage-gated channel subunit alpha 1 C (CACNA1C) gene, encoding the CaV1.2 α1-subunit, cause Timothy syndrome (TS), a multisystemic disorder that includes autism spectrum disorders and long QT (LQT) syndrome. Strikingly, TS patients frequently suffer from hypoglycemia of yet unproven origin. Using next-generation sequencing, we identified a novel heterozygous CACNA1C mutation in a patient with congenital hyperinsulinism (CHI) and associated hypoglycemic episodes. We characterized the electrophysiological phenotype of the mutated channel using voltage-clamp recordings and in silico action potential modeling experiments. The identified CaV1.2L566P mutation causes a mixed electrophysiological phenotype of gain- and loss-of-function effects. In silico action potential modeling supports that this mixed electrophysiological phenotype leads to a tissue-specific impact on beta cells compared to cardiomyocytes. Thus, CACNA1C variants may be associated with non-syndromic hyperinsulinemic hypoglycemia without long-QT syndrome, explained by very specific electrophysiological properties of the mutated channel. We discuss different biochemical characteristics and clinical impacts of hypoglycemia in the context of CACNA1C variants and show that these may be associated with significant morbidity for Timothy Syndrome patients. Our findings underline that the potential of hypoglycemia warrants careful attention in patients with CACNA1C variants, and such variants should be included in the differential diagnosis of non-syndromic congenital hyperinsulinism.

Safety and Efficacy of Lonapegsomatropin in Children With Growth Hormone Deficiency: enliGHten Trial 2-Year Results.

PURPOSE: The objectives of the ongoing, Phase 3, open-label extension trial enliGHten are to assess the long-term safety and efficacy of weekly administered long-acting growth hormone lonapegsomatropin in children with growth hormone deficiency. METHODS: Eligible subjects completing a prior Phase 3 lonapegsomatropin parent trial (heiGHt or fliGHt) were invited to participate. All subjects were treated with lonapegsomatropin. Subjects in the United States switched to the TransCon hGH Auto-Injector when available. Endpoints were long-term safety, annualized height velocity, pharmacodynamics [insulin-like growth factor-1 SD score (SDS) values], and patient- and caregiver-reported assessments of convenience and tolerability. RESULTS: Lonapegsomatropin treatment during enliGHten was associated with continued improvements in height SDS through week 104 in treatment-naïve subjects from the heiGHt trial (-2.89 to -1.37 for the lonapegsomatropin group; -3.0 to -1.52 for the daily somatropin group). Height SDS also continued to improve among switch subjects from the fliGHt trial (-1.42 at fliGHt baseline to -0.69 at week 78). After 104 weeks, the average bone age/chronological age ratio for each treatment group was 0.8 (0.1), showing only minimal advancement of bone age relative to chronological age with continued lonapegsomatropin treatment among heiGHt subjects. Fewer local tolerability reactions were reported with the TransCon hGH Auto-Injector compared with syringe/needle. CONCLUSIONS: Treatment with lonapegsomatropin continued to be safe and well-tolerated, with no new safety signals identified. Children treated with once-weekly lonapegsomatropin showed continued improvement of height SDS through the second year of therapy without excess advancement of bone age.

Switching to Weekly Lonapegsomatropin from Daily Somatropin in Children with Growth Hormone Deficiency: The fliGHt Trial.

INTRODUCTION: The phase 3 fliGHt Trial evaluated the safety and tolerability of once-weekly lonapegsomatropin, a long-acting prodrug, in children with growth hormone deficiency (GHD) who switched from daily somatropin therapy to lonapegsomatropin. METHODS: This multicenter, open-label, 26-week phase 3 trial took place at 28 sites across 4 countries (Australia, Canada, New Zealand, and the USA). The trial enrolled 146 children with GHD, 143 of which were previously treated with daily somatropin. All subjects received once-weekly lonapegsomatropin 0.24 mg human growth hormone/kg/week. The primary outcome measure was safety and tolerability of lonapegsomatropin over 26 weeks. Secondary outcome measures assessed annualized height velocity (AHV), height standard deviation score (SDS), and IGF-1 SDS at 26 weeks. RESULTS: Subjects had a mean prior daily somatropin dose of 0.29 mg/kg/week. Treatment-emergent adverse events (AEs) reported were similar to the published AE profile of daily somatropin therapies. After switching to lonapegsomatropin, the least-squares mean (LSM) AHV was 8.7 cm/year (95% CI: 8.2, 9.2) at Week 26 and LSM height SDS changed from baseline to Week 26 of +0.25 (95% CI: 0.21, 0.29). Among switch subjects, the LSM for average IGF-1 SDS was sustained at Weeks 13 and 26, representing an approximate 0.7 increase from baseline (prior to switching from daily somatropin therapy). Patient-reported outcomes indicated a preference for weekly lonapegsomatropin among both children and their parents. CONCLUSIONS: Lonapegsomatropin treatment outcomes were as expected across a range of ages and treatment experiences. Switching to lonapegsomatropin resulted in a similar AE profile to daily somatropin therapy.

Congenital hyperinsulinism in infancy and childhood: challenges, unmet needs and the perspective of patients and families.

BACKGROUND: Congenital hyperinsulinism (CHI) is the most common cause of persistent hypoglycemia in infants and children, and carries a considerable risk of neurological damage and developmental delays if diagnosis and treatment are delayed. Despite rapid advances in diagnosis and management, long-term developmental outcomes have not significantly improved in the past years. CHI remains a disease that is associated with significant morbidity, and psychosocial and financial burden for affected families, especially concerning the need for constant blood glucose monitoring throughout patients' lives. RESULTS: In this review, we discuss the key clinical challenges and unmet needs, and present insights on patients' and families' perspective on their daily life with CHI. Prevention of neurocognitive impairment and successful management of patients with CHI largely depend on early diagnosis and effective treatment by a multidisciplinary team of specialists with experience in the disease. CONCLUSIONS: To ensure the best outcomes for patients and their families, improvements in effective screening and treatment, and accelerated referral to specialized centers need to be implemented. There is a need to develop a wider range of centers of excellence and networks of specialized care to optimize the best outcomes both for patients and for clinicians. Awareness of the presentation and the risks of CHI has to be raised across all professions involved in the care of newborns and infants. For many patients, the limited treatment options currently available are insufficient to manage the disease effectively, and they are associated with a range of adverse events. New therapies would benefit all patients, even those that are relatively stable on current treatments, by reducing the need for constant blood glucose monitoring and facilitating a personalized approach to treatment.

Congenital hyperinsulinism (CHI) is a rare disease that causes newborn babies and children to have low blood sugar because of the abnormal release of insulin. Insulin is a hormone produced by the pancreas that promotes the transfer of sugar from the blood into the body's cells. In a healthy person, insulin is released only after a meal when the level of blood sugar is high, but infants and children with CHI make insulin even if the blood sugar is low. This can lead to dangerously low blood sugar levels, which can cause brain damage if left untreated. Unfortunately, diagnosis and treatment are often delayed, resulting in avoidable brain damage and developmental delays in these children. CHI is associated with substantial stress and anxiety for the families, especially due to the need for frequent feeding and the fear of low blood sugars added to the constant need to measure blood sugar levels. This article discusses the most important challenges and unmet needs in this rare disease, including the limited treatment options, the side effects of available treatment options and the heavy psychological, social and financial burden on affected families. Effective screening of newborns for CHI needs to be improved, and quick referral to specialized treatment centers is necessary to ensure the best outcomes for patients and families. In addition, awareness of CHI has to be raised in all medical professions caring for newborns and infants, and new medications are urgently needed to ensure the best possible treatment for all patients with CHI.

Weekly Lonapegsomatropin in Treatment-Naïve Children With Growth Hormone Deficiency: The Phase 3 heiGHt Trial.

CONTEXT: For children with growth hormone deficiency (GHD), treatment burden with daily somatropin injections [human growth hormone (hGH)] is high, which may lead to poor adherence and suboptimal overall treatment outcomes. Lonapegsomatropin (TransCon hGH) is an investigational long-acting, once-weekly prodrug for the treatment of GHD. OBJECTIVE: The objective of this study was to evaluate the efficacy and safety of once-weekly lonapegsomatropin vs daily somatropin. DESIGN: The heiGHt trial was a randomized, open-label, active-controlled, 52-week Phase 3 trial (NCT02781727). SETTING: This trial took place at 73 sites across 15 countries. PATIENTS: This trial enrolled and dosed 161 treatment-naïve, prepubertal patients with GHD. INTERVENTIONS: Patients were randomized 2:1 to receive lonapegsomatropin 0.24 mg hGH/kg/week or an equivalent weekly dose of somatropin delivered daily. MAIN OUTCOME MEASURE: The primary end point was annualized height velocity (AHV) at week 52. Secondary efficacy end points included change from baseline in height SD scores (SDS). RESULTS: Least squares (LS) mean (SE) AHV at 52 weeks was 11.2 (0.2) cm/year for lonapegsomatropin vs 10.3 (0.3) cm/year for daily somatropin (P = 0.009), with lonapegsomatropin demonstrating both noninferiority and superiority over daily somatropin. LS mean (SE) height SDS increased from baseline to week 52 by 1.10 (0.04) vs 0.96 (0.05) in the weekly lonapegsomatropin vs daily somatropin groups (P = 0.01). Bone age/chronological age ratio, adverse events, tolerability, and immunogenicity were similar between groups. CONCLUSIONS: The trial met its primary objective of noninferiority in AHV and further showed superiority of lonapegsomatropin compared to daily somatropin, with similar safety, in treatment-naïve children with GHD.

Recent updates in the management of infants and children with hyperinsulinism.

PURPOSE OF REVIEW: To highlight recent advances in early diagnosis and the changing treatment paradigm for hyperinsulinism (HI) which can result in shorter hospitalizations, higher rates of cure and improved neurological outcome. RECENT FINDINGS: Recent literature has shown that following publication of the pediatric endocrinology society guidelines for diagnosing hypoglycemia there have been higher rates of diagnosis of acquired and genetic HI. Studies of neurological outcome have found that poor outcomes are associated with delay between initial hypoglycemia and instigation of treatment for HI, hypoglycemic seizures and frequency of glucose <20 mg/dL. Rapid genetic testing can decrease the time from the discovery of diazoxide unresponsiveness to referral to multidisciplinary centers with the availability of 18-F-L 3,4-Dihydroxyphenylalanine positron emission tomography (18F-DOPA PET). Proper selection of patients for 18F-DOPA PET and careful interpretation of the images can result in greater than 90% cure for patients with focal HI. SUMMARY: Recent advances in the early diagnosis of HI and rapid turnaround genetic testing can lead to prompt transfer to centers with multidisciplinary care teams where proper selection of patients for 18F-DOPA PET scan gives the best opportunity for cure for patients with focal disease. Minimizing severe hypoglycemia maximizes the opportunity for improved neurological outcome.

Visual interpretation, not SUV ratios, is the ideal method to interpret 18F-DOPA PET scans to aid in the cure of patients with focal congenital hyperinsulinism.

INTRODUCTION: Congenital hyperinsulinism is characterized by abnormal regulation of insulin secretion from the pancreas causing profound hypoketotic hypoglycemia and is the leading cause of persistent hypoglycemia in infants and children. The main objective of this study is to highlight the different mechanisms to interpret the 18F-DOPA PET scans and how this can influence outcomes. MATERIALS AND METHODS: After 18F-Fluoro-L-DOPA was injected intravenously into 50 subjects' arm at a dose of 2.96-5.92 MBq/kg, three to four single-bed position PET scans were acquired at 20, 30, 40 and 50-minute post injection. The radiologist interpreted the scans for focal and diffuse hyperinsulinism using a visual interpretation method, as well as determining the Standard Uptake Value ratios with varying cut-offs. RESULTS: Visual interpretation had the combination of the best sensitivity and positive prediction values. CONCLUSIONS: In patients with focal disease, SUV ratios are not as accurate in identifying the focal lesion as visual inspection, and cases of focal disease may be missed by those relying on SUV ratios, thereby denying the patients a chance of cure. We recommend treating patients with diazoxide-resistant hyperinsulinism in centers with dedicated multidisciplinary team comprising of at least a pediatric endocrinologist with a special interest in hyperinsulinism, a radiologist experienced in interpretation of 18F-Fluoro-L-DOPA PET/CT scans, a histopathologist with experience in frozen section analysis of the pancreas and a pancreatic surgeon experienced in partial pancreatectomies in patients with hyperinsulinism.

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.

PRACTICE VARIATION IN THE MANAGEMENT OF GIRLS AND BOYS WITH DELAYED PUBERTY.

Objective: Delayed puberty is a common condition, and typical management includes "watchful waiting" and/or sex-steroid therapy. We sought to characterize treatment practices and to assess provider comfort with the management of delayed puberty in girls and boys. Methods: A national survey of pediatric endocrine providers assessed definitions of delayed puberty, practices around sex-steroid therapy, reasons for treatment, and comfort in managing delayed puberty in girls and boys. Results: Of 184 respondents (12% participation rate), 64% and 71% used the traditional age cutoffs for defining delayed puberty of 13 years for girls and 14 years for boys, respectively. Nearly half (45%) of providers would treat boys relatively earlier than girls, compared to 18% who would treat girls relatively earlier (P<.0001). Providers were more likely to cite bone density as a reason to treat girls and alleviating patient and parental distress, accelerating growth, and "jump starting" puberty as reasons to treat boys. Greater experience in endocrine practice was associated with greater comfort managing delayed puberty in both boys and girls. Approximately 80% of providers agreed that clinical guidelines are needed for the management of delayed puberty. Conclusion: There is a high degree of variability in the clinical management of delayed puberty, and our results suggest that providers are more hesitant to treat girls compared to boys and have different reasons for treating each. It remains to be determined if these discrepancies in treatment are justified by biologic differences between girls and boys or represent nonevidence-based disparities in care. Abbreviation: U.S. = United States.