Hyperinsulinemic Hypoglycemia

Effective and safe use of sirolimus in hyperinsulinemic hypoglycaemia refractory to medical and surgical therapy: a case series and review of literature

OBJECTIVES

Hyperinsulinemic hypoglycaemia (HH) presents significant management challenges, especially in cases refractory to standard therapies. This case series aims to report the efficacy and safety of sirolimus, an mTOR inhibitor, as an adjunctive therapy in persistent HH, noting that current clinical guidelines caution its use outside of research.

CASE PRESENTATION

We report a case series from two paediatric endocrinology centres across Australia, describing use of sirolimus in four infants with persistent HH refractory to conventional treatments or post near-total pancreatectomy. Retrospective chart reviews provided clinical and biochemical data, documenting each patient's sirolimus dosing, treatment responses, and adverse events.

CONCLUSIONS

Sirolimus emerged as a useful and safe adjunct, enabling hospital discharge, and demonstrating efficacy even at lower serum trough levels. Despite safety concerns, including recurrent viral infections in one patient, sirolimus was generally well-tolerated. We advocate for implementing risk mitigation strategies, including a multidisciplinary approach, and maintaining lower sirolimus trough levels than previously recommended. Careful consideration of sirolimus is warranted in select cases of severe diffuse HH, emphasising ongoing monitoring for adverse effects and further research to refine treatment guidelines.

Mind the Decimal Point: A Case of Diazoxide Overdose-Induced Ileus

Diazoxide is the only medication approved by the United States Food and Drug Administration for the treatment of hyperinsulinism-induced hypoglycemia. Overdose is infrequently reported. This case describes a preterm four-week-old male who was prescribed diazoxide and chlorothiazide for perinatal stress-induced hyperinsulinism. The patient presented to the emergency department with feeding intolerance and abdominal distension following an accidental 10-fold diazoxide overdose. On presentation, vital signs were remarkable for tachycardia and intermittent tachypnea. Physical exam revealed a grossly distended abdomen. Laboratory abnormalities included a glucose of 216 mg/dL, sodium of 132 mmol/L, and chloride of 98 mmol/L. Abdominal X-ray interpretation found moderate gaseous distension suggestive of generalized ileus. The patient was admitted to the neonatal intensive care unit (NICU), and a nasogastric tube was placed. He received intravenous dextrose fluids, and enteral feeds were resumed as serial X-rays showed interval improvement. The patient remained in the NICU for several days to monitor bowel movements and resolution of ileus and he was discharged after improvement. While diazoxide overdose is rarely reported, and ileus due to such is documented even less frequently, 10-fold medication dose errors are common among infants. The source of the 10-fold mistake is often decimal points, leading zeros, or trailing zeros. Utilizing the smallest possible syringe for the prescribed dose may reduce the incidence of medication errors.

Low-dose diazoxide is safe and effective in infants with transient hyperinsulinism

OBJECTIVE

Transient hyperinsulinism (THI) is the most common form of recurrent hypoglycaemia in neonates beyond the first week of life. Although self-resolving, treatment can be required. Consensus guidelines recommend the lower end of the diazoxide 5-15 mg/kg/day range in THI to reduce the risk of adverse events. We sought to determine if doses <5 mg/kg/day of diazoxide can be effective in THI.

DESIGN, PATIENTS, MEASURMENTS

Infants with THI (duration <6 months) were treated with low-dose diazoxide from October 2015 to February 2021. Dosing was based on weight at diazoxide start: 2 mg/kg/day in infants 1000-2000 g (cohort 1), 3 mg/kg/day in those 2000-3500 g (cohort 2) and 5 mg/kg/day in those >3500 g.

RESULTS

A total of 73 infants with THI (77% male, 33% preterm, 52% small-for-gestational age) were commenced on diazoxide at a median age of 11 days (range 3-43) for a median duration of 4 months (0.3-6.8), with no difference between cohorts. The mean effective diazoxide dose was 3 mg/kg/day (range 1.5-10); 35% (26/73) required an increase from their starting dose, including 60% (9/15) of cohort 1. There was no association between perinatal stress risk factors or treatment-related characteristics and dose increase. Adverse events occurred in 13 patients (18%); oedema (12%) and hyponatraemia (5%) were the most common. Two infants developed suspected necrotising enterocolitis (NEC); none had pulmonary hypertension.

CONCLUSION

Diazoxide doses <5 mg/kg/day are effective in THI. While the nature of the association between diazoxide and NEC was unclear, other adverse events were mild. We suggest considering starting doses as low as 2-3 mg/kg/day in THI to balance the side effect risk while maintaining euglycaemia.

Umbilical artery cord blood glucose predicted hypoglycemia in gestational diabetes mellitus and other at-risk newborns

BACKGROUND

To explore the value of umbilical artery cord blood glucose (UACBG) in predicting hypoglycemia in gestational diabetes mellitus (GDM) and other at-risk newborns, and to provide a cut-off UACBG value for predicting hypoglycemia occurrence.

METHODS

In this prospective study, we enrolled at-risk infants delivered vaginally, including neonates born to mothers with GDM, premature, macrosomic, and low birth weight. We separated the infants into GDM group and other at-risk group. All subjects underwent UACBG measurement during delivery. Neonatal peripheral blood glucose measurement was performed at 0.5 and 2 h after birth. The predictive performance of UACBG for neonatal hypoglycemia was assessed using receiver operating characteristic curve (ROC), area under curve (AUC), sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV).

RESULTS

916 newborns were included, with 538 in GDM group and 378 in other at-risk group. 85 neonates were diagnosed hypoglycemia within 2 h after birth, including 36 belonging to GDM group and 49 to other at-risk group. For hypoglycemia prediction within 2 h, the best cut-off of UACBG was 4.150 mmol/L, yielding an AUC of 0.688 (95% CI 0.625-0.751) and a NPV of 0.933. In detail, the AUC was 0.680 in GDM group (95% CI 0.589-0.771), with the optimal cut-off of 4.150 mmol/L and a NPV of 0.950. In other at-risk group, the AUC was 0.678(95% CI 0.586-0.771), the best threshold was 3.950 mmol/L and the NPV was 0.908. No significant differences were observed between GDM group and other at-risk group in AUC at 0.5 h, 2 h and within 2 h.

CONCLUSIONS

UACBG has a high NPV for predicting neonatal hypoglycemia within 2 h after birth. It was implied that individuals with cord blood glucose levels above the threshold were at lower risk for hypoglycemia. UACBG monitoring provides evidence for subsequent classified management of hypoglycemia.

Hyperinsulinism-hyperammonemia syndrome in two Peruvian children with refractory epilepsy

OBJECTIVES

Congenital hyperinsulinism (HI) is a heterogeneous clinical disorder with great variability in its clinical phenotype, and to date, pathogenic variants in 23 genes have been recognized.  Hyperinsulinism-hyperammonemia syndrome (HI/HA) is the second most frequent cause of this disease that shows an autosomal dominant pattern and is caused by an activating mutation of the GLUD1 gene, which responds favorably to the use of diazoxide. HI/HA syndrome presents with fasting hypoglycemia; postprandial hypoglycemia, especially in those with a high protein content (leucine); and persistent mild hyperammonemia. Neurological abnormalities, in the form of epilepsy or neurodevelopmental delay, are observed in a high percentage of patients; therefore, timely diagnosis is crucial for proper management.

CASE PRESENTATION

We report the clinical presentation of two Peruvian children that presented with epilepsy whose genetic analysis revealed a missense mutation in the GLUD1 gene, one within exon 11, at 22% mosaicism; and another within exon 7, as well as their response to diazoxide therapy. To the best of our knowledge, these are the first two cases of HI/HA syndrome reported in Peru.

CONCLUSIONS

HI/HA syndrome went unnoticed, because hypoglycemia was missed and were considered partially controlled epilepsies. A failure to recognize hypoglycemic seizures will delay diagnosis and adequate treatment, so a proper investigation could avoid irreversible neurological damage.

Energy Crisis Links to Autophagy and Ferroptosis in Alzheimer's Disease: Current Evidence and Future Avenues

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases worldwide. The occult nature of the onset and the uncertainty of the etiology largely impede the development of therapeutic strategies for AD. Previous studies revealed that the disorder of energy metabolism in the brains of AD patients appears far earlier than the typical pathological features of AD, suggesting a tight association between energy crisis and the onset of AD. Energy crisis in the brain is known to be induced by the reductions in glucose uptake and utilization, which may be ascribed to the diminished expressions of cerebral glucose transporters (GLUTs), insulin resistance, mitochondrial dysfunctions, and lactate dysmetabolism. Notably, the energy sensors such as peroxisome proliferators-activated receptor (PPAR), transcription factor EB (TFEB), and AMP-activated protein kinase (AMPK) were shown to be the critical regulators of autophagy, which play important roles in regulating beta-amyloid (Aβ) metabolism, tau phosphorylation, neuroinflammation, iron dynamics, as well as ferroptosis. In this study, we summarized the current knowledge on the molecular mechanisms involved in the energy dysmetabolism of AD and discussed the interplays existing between energy crisis, autophagy, and ferroptosis. In addition, we highlighted the potential network in which autophagy may serve as a bridge between energy crisis and ferroptosis in the progression of AD. A deeper understanding of the relationship between energy dysmetabolism and AD may provide new insight into developing strategies for treating AD; meanwhile, the energy crisis in the progression of AD should gain more attention.

Establishing the Optimal Time for Induction of Labor in Women with Diet-Controlled Gestational Diabetes Mellitus: A Single-Center Observational Study

To determine the optimal week for labor induction in women with diet-controlled gestational diabetes mellitus by comparing differences in perinatal and neonatal outcomes of labor induction to expectant management at different gestational weeks. Methods: This was a retrospective analysis of a prospectively recruited cohort of 797 singleton pregnancies complicated by diet-controlled gestational diabetes mellitus that were diagnosed, treated, and delivered after 37 weeks in a tertiary, university-affiliated perinatal center between January 2016 and December 2021. Results: The incidence of neonatal complications was highest when delivery occurred at 37 weeks, whereas fetal macrosomia occurred mostly at 41 weeks (20.7%); the frequency of large for gestational age infants did not differ between the groups. Conversely, the best neonatal outcomes were observed at 40 weeks due to the lowest number of neonates requiring phototherapy for neonatal jaundice (1.7%) and the smallest proportion of neonates experiencing composite adverse neonatal outcomes defined as neonatal hypoglycemia, phototherapy, clavicle fracture, or umbilical artery pH < 7.15 (10.4%). Compared with expectant management, the risk for neonatal hypoglycemia was increased for induction at 39 weeks (adjusted odds ratio 12.29, 95% confidence interval 1.35−111.75, p = 0.026) and that for fetal macrosomia was decreased for induction at 40 weeks (adjusted odds ratio 0.11, 95% confidence interval 0.01−0.92, p = 0.041), after adjusting for maternal pre-pregnancy body mass index, nulliparity, and mean pregnancy A1c. Conclusions: The lowest rate of neonatal complications was observed at 40 weeks. Labor induction at 40 weeks prevented fetal macrosomia.

Incidence and Risk Factors for Glucose Disturbances in Premature Infants

Background and Objectives: There are limited data regarding the incidence and risk factors for hypoglycemia, hyperglycemia, and unstable glycemia in preterm infants. The aim of the present study was to determine the incidence and risk factors associated with neonatal hypoglycemia, hyperglycemia, and unstable glycemia in preterm infants during the first seven days of life. Materials and Methods: This prospective study included preterm infants <37 weeks of gestation, admitted to the Neonatal Intensive Care Unit between January 2018 and December 2020. Based on blood glucose levels in the first week of life, infants were divided into the following four groups: normoglycemic, hypoglycemic, hyperglycemic, and unstable. Blood glucose levels were measured from capillary blood at the 1st, 3rd, 6th, and 12th hour of life during the first 24 h, and at least once a day from days 2 to 7, prefeed. Results: Of 445 enrolled infants, 20.7% (92/445) were categorized as hypoglycemic, 9.9% (44/445) as hyperglycemic, and 2.9% (13/445) as unstable, respectively. Hypoglycemia was most commonly observed among infants ≥34 weeks (27.9%), and hyperglycemia was most common among preterm infants <28 weeks (50%). Female gender increased the chances of developing hypoglycemia by three times. The decrease in gestational age by one week increased the chance of developing hyperglycemia by 1.9 times. Sepsis increased the chance of developing hyperglycemia seven times, respiratory distress syndrome five times, and mechanical ventilation three times, respectively. Conclusions: Glucose disturbances in the early neonatal period in preterm infants are common and mostly asymptomatic. Therefore, careful blood glucose level monitoring is required in those infants, especially in late preterm infants, in order to prevent possible neurological complications.

Therapeutic RNA-silencing oligonucleotides in metabolic diseases

Recent years have seen unprecedented activity in the development of RNA-silencing oligonucleotide therapeutics for metabolic diseases. Improved oligonucleotide design and optimization of synthetic nucleic acid chemistry, in combination with the development of highly selective and efficient conjugate delivery technology platforms, have established and validated oligonucleotides as a new class of drugs. To date, there are five marketed oligonucleotide therapies, with many more in clinical studies, for both rare and common liver-driven metabolic diseases. Here, we provide an overview of recent developments in the field of oligonucleotide therapeutics in metabolism, review past and current clinical trials, and discuss ongoing challenges and possible future developments.

Anxiety, depression, and quality of life in parents of children with congenital hyperinsulinism

This study aimed to assess mental health, family burden, and quality of life (PQoL) in parents of children with persistent congenital hyperinsulinism (CHI). Forty-eight individual CHI parents (75% female) completed self-reported questionnaires and screening tools for anxiety (GAD-7), depression (PHQ-8), PQoL (ULQIE), and family burden (FaBeL). Additional data on sociodemographics, social support, and child- and disease-related data were recorded. 29.8% of parents showed major depressive symptoms and 38.3% had a probable general anxiety disorder, including 20.8% who had both. The family burden was moderate and assessment of PQoL yielded average scores. Neurological impairment in an affected child (p = .002 and p < .001, respectively) and lower working hours (p = .001 and p = .012, respectively) were the strongest predictors of worse GAD-7 and PHQ-8 scores. Furthermore, lower working hours (p = .012) and comorbidities in the affected child (p = .007) were significantly associated with lower PQoL. Mothers had worse GAD-7 scores (p = .006) and lower PQoL (p = .035) than fathers. Indication of sleep disturbance was associated with worse PHQ-8 scores (p = .003), higher family burden (p = .039), and reduced PQoL (p = .003). A higher number of caretakers besides parents was associated with decreased family burden (p = .019), improved PQoL (p < .001), and lower scores for anxiety (p = .016) and depressive (p = .021) symptoms.    Conclusion: Symptoms of depression and anxiety are alarmingly prevalent in parents of children with CHI. Psychological screening of parents should be initiated to ensure early identification of psychological strains and psychosocial support should be offered as needed. A good support network and regular work activities can improve parental mental health and well-being. What is Known: • Psychosocial strains and reduced quality of life are common in parents of chronically ill children. What is New: • In this first study evaluating mental health, family burden, and quality of life in parents of children with congenital hyperinsulinism (CHI), symptoms of depression and anxiety were alarmingly prevalent. • Parents of children with CHI should receive regular psychological screening and psychosocial support should be offered as needed. A good support network and regular work activities can improve parental mental health and well-being.

Hyperinsulinemic Hypoglycemia in Three Generations of a Family with Glucokinase Activating Mutation, c.295T>C (p.Trp99Arg)

Familial Hyperinsulinemic Hypoglycemia (FHH) is a very rare disease with heterogeneous clinical manifestations. There are only a few reports of heterozygous activating mutations of glucokinase (GCK) attributable to FHH, with no reports describing effects in the course in pregnancy with affected mother/affected child. A large kindred with FHH and GCK:c.295T>C (p.Trp99Arg) pathogenic variant was identified in which four family members from three generations were affected. The clinical follow up in one clinical center lasted up to 30 years, with different times of diagnosis ranging from neonate period to adulthood. The severity of hypoglycemia was mild/severe and fasting was the trigger for hypoglycemia. Response to diazoxide varied from good, in the neonate, to moderate/poor, in childhood/adulthood; however, this was biased by poor compliance. Treatment with somatostatin analogues was discontinued due to side effects. Over time, patients developed clinical adaptation to very low glucose levels. During pregnancy, episodes of severe hypoglycemia in the first trimester were observed, which responded very well to steroids. The clinical course of the GCK:c.295T>C (p.Trp99Arg) mutation varied in the same family, with the development of clinical adaptation to very low glucose levels over time. Treatment with steroids might prevent hypoglycemia during pregnancy in an affected mother.

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.

Necrotising enterocolitis in newborns receiving diazoxide

BACKGROUND

Frequent and severe gastrointestinal disturbances have been reported with the use of diazoxide in adults and older children. However, no studies have investigated the incidence of necrotising enterocolitis (NEC) in diazoxide-exposed newborns.

OBJECTIVE

To evaluate a possible association between diazoxide treatment for neonatal hypoglycaemia and the occurrence of NEC.

DESIGN

Multicentre retrospective cohort study.

SETTING

Three tertiary neonatal intensive care units in Toronto, Canada.

PATIENTS

All patients treated with diazoxide for persistent hypoglycaemia between July 2012 and June 2017 were included. Overall incidence of NEC during those years on the participating units was obtained for comparison from the Canadian Neonatal Network database.

MAIN OUTCOME

Incidence of NEC after diazoxide exposure.

RESULTS

Fifty-five neonates were exposed to diazoxide during the study period. Eighteen patients (33%) showed signs of feeding intolerance, and 7 developed NEC (13%). A diagnosis of NEC was more prevalent in the diazoxide-exposed, as compared with non-exposed infants of similar gestational age (OR 5.07, 95% CI 2.27 to 11.27; p<0.001), and greatest among infants born at 33-36 weeks' gestation (OR 13.76, 95% CI 3.77 to 50.23; p<0.001). All but one of the neonates diagnosed with NEC developed the disease within 7 days from initiation of diazoxide treatment.

CONCLUSION

The present data suggest a possible association between diazoxide exposure and the development of NEC in neonates. Further evaluation of the diazoxide-associated risk of NEC in neonates treated for persistent hypoglycaemia is warranted.

Experience with Real-Time Continuous Glucose Monitoring in Newborns with Congenital Hyperinsulinemic Hypoglycemia

BACKGROUND

Effective treatment and close monitoring of hypoglycemia in children with congenital hyperinsulinemic hypoglycemia (CHH) is vital to prevent brain damage. The current use of capillary sampling schedules does not provide a comprehensive assessment of glycemic status and fails to detect asymptomatic hypoglycemia episodes.

AIM

To investigate the efficacy and accuracy of a real-time continuous glucose monitoring system (RT-CGMS) in neonates with CHH.

METHODS

A sensor connected to RT-CGMS was inserted into the newborn patients and maintained for at least 6 days during their stay in the hospital. We compared the readings of CGMS with capillary blood glucose values using Bland-Altman analysis.

RESULTS

A total of 110 blood glucose values were compared to readings from the CGMS. All results were calculated and plotted for CGMS values at 0-4, 5-9, 10-14, 15-19, 20-24, and 25-29 min after capillary blood glucose sampling. CGMS readings were highly correlated with blood glucose values, especially during normoglycemia. In case of hypoglycemia, the mean difference between the CGMS and capillary glucose values was higher. Although the false positive rate for hypoglycemia was relatively high in CGMS, RT-CGMS may show some episodes of hypoglycemia earlier than blood measurement.

CONCLUSION

RT-CGMS is accurate during normoglycemia, and it can reduce the number of capillary blood samples in children with CHH.

Activation of Protein Kinase A (PKA) signaling mitigates congenital hyperinsulinism associated hypoglycemia in the Sur1-/- mouse model

There is a significant unmet need for a safe and effective therapy for the treatment of children with congenital hyperinsulinism. We hypothesized that amplification of the glucagon signaling pathway could ameliorate hyperinsulinism associated hypoglycemia. In order to test this we evaluated the effects of loss of Prkar1a, a negative regulator of Protein Kinase A in the context of hyperinsulinemic conditions. With reduction of Prkar1a expression, we observed a significant upregulation of hepatic gluconeogenic genes. In wild type mice receiving a continuous infusion of insulin by mini-osmotic pump, we observed a 2-fold increase in the level of circulating ketones and a more than 40-fold increase in Kiss1 expression with reduction of Prkar1a. Loss of Prkar1a in the Sur1^-/- mouse model of K_ATP hyperinsulinism significantly attenuated fasting induced hypoglycemia, decreased the insulin/glucose ratio, and also increased the hepatic expression of Kiss1 by more than 10-fold. Together these data demonstrate that amplification of the hepatic glucagon signaling pathway is able to rescue hypoglycemia caused by hyperinsulinism.

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.

Incidence and Risk Factors for Hypoglycemia During Fetal-to-Neonatal Transition in Premature Infants

Objective: To determine the incidence and risk factors associated with neonatal hypoglycemia in the premature population <33 weeks' gestation. Methods: This was a secondary retrospective analysis from previous infants enrolled in randomized controlled trials. A total of 255 infants <33 weeks' gestation were born during the study period. Eight infants were excluded due to missing glucose or maternal data and 175 infants were analyzed. Main outcome measures: Primary outcome was hypoglycemia (blood glucose <2.6mmol/L) determined via glucose oxidase method on arterial or venous blood gas. Birth weight subgroups: small for gestational age (SGA, birth weight <10%ile for gestational age) and large for gestational age (LGA, birth weight >90%ile for gestational age). Maternal hypertension was systolic blood pressure >140mmHg. Results: 175 infants <33 weeks' gestational age (89 male, 84 female) were analyzed. Hypoglycemia occurred in 59 infants (33.7%). Maternal hypertension (OR 3.07, 95% CI 1.51-6.30, p = 0.002) was the sole risk factor for neonatal hypoglycemia. Protective factors for hypoglycemia included labor at time of delivery (OR 4.51, 95% CI 2.29-9.18, p <0.0001) and antenatal magnesium sulfate (OR 2.53, 95% CI 1.23-5.50, p = 0.01). There were no significant differences between hypoglycemic and euglycemic infants in sex, gestational age, LGA infants, antenatal steroids, vaginal birth, or maternal diabetes. SGA infants were excluded from analysis due to sample size. Conclusions: Premature infants <33 weeks' gestation have increased risk of hypoglycemia. Maternal hypertension increases hypoglycemia risk. Antenatal magnesium sulfate administration or labor at time of delivery decrease hypoglycemia risk.

The Genetic and Molecular Mechanisms of Congenital Hyperinsulinism

Congenital hyperinsulinism (CHI) is a heterogenous and complex disorder in which the unregulated insulin secretion from pancreatic beta-cells leads to hyperinsulinaemic hypoglycaemia. The severity of hypoglycaemia varies depending on the underlying molecular mechanism and genetic defects. The genetic and molecular causes of CHI include defects in pivotal pathways regulating the secretion of insulin from the beta-cell. Broadly these genetic defects leading to unregulated insulin secretion can be grouped into four main categories. The first group consists of defects in the pancreatic KATP channel genes (ABCC8 and KCNJ11). The second and third categories of conditions are enzymatic defects (such as GDH, GCK, HADH) and defects in transcription factors (for example HNF1α, HNF4α) leading to changes in nutrient flux into metabolic pathways which converge on insulin secretion. Lastly, a large number of genetic syndromes are now linked to hyperinsulinaemic hypoglycaemia. As the molecular and genetic basis of CHI has expanded over the last few years, this review aims to provide an up-to-date knowledge on the genetic causes of CHI.

Genotype and phenotype analysis of a cohort of patients with congenital hyperinsulinism based on DOPA-PET CT scanning

Congenital hyperinsulinism (CHI) is a clinically, genetically, and morphologically heterogeneous disorder. ¹⁸F DOPA-PET CT scanning greatly improves its clinical outcome. Here, we presented the first Chinese ¹⁸F DOPA-PET CT scanning-based CHI cohort highlighting the variable ethic clinical phenotypes and genotypes. Fifty CHI patients were recruited. Median age at presentation was 2 days. Median fasting time was 2 h. Mean insulin level was 25.6 μIU/ml. Fifty-two percent of patients were diazoxide-unresponsive with significantly shorter fasting tolerance time and higher serum insulin level compared with the responsive patients. Seventy-four percent of patients experienced at least one adverse drug reaction. Tremendously increased focal lesions (32%) were detected and 75% of them were cured through surgery. Thirty-one nucleotide sequence changes were identified in 48% patients. Four novel variants (Q608X, Q1347X, Q289X, F1489S) in ABCC8 gene and 2 novel variants (G132A, V138E) in KCNJ11 gene were detected. Of the variants, 87.1% harbored in ABCC and KCNJ11 genes. T1042Qfs*75 in ABCC8 gene was the most common mutation.Conclusion: Highly increased portion of focal lesion was presented in Chinese CHI patients compared with that of the previous reports. Intolerance to diazoxide was much more evident in Chinese or East Asian than other populations. Certain hotspot mutations harbored in Chinese CHI patients. What is Known: • ¹⁸F DOPA-PET CT scanning can provide informative guidance for surgical procedure when medical therapy is not well responded in CHI patients. What is New: • Intolerance to diazoxide is much more evident in Chinese and East Asian CHI patients compared with the other ethnic populations. • Novel mutations were detected in ABCC8 and KCNJ11 gene. Hotspot mutations such as T1042Qfs*75, I1511K, E501K, G111R in ABCC8 gene, and R34H in KCNJ11 gene are predominantly responsible for Chinese CHI patients.

Transient neonatal hyperinsulinaemic hypoglycaemia: perinatal predictors of length and cost of stay

Admission to neonatal care causes separation of infants from their parents, can adversely affect breast-feeding and is associated with painful procedures. Our aim was to identify perinatal factors and cost of care associated with transient neonatal hyperinsulinaemic hypoglycaemia (HH). Infants born after 35 weeks of gestation admitted because of hypoglycaemia were studied. The neonates were divided into two groups (HH and non-HH), and their length and cost of care were compared and perinatal factors predicting those outcomes explored. Forty of the 474 infants admitted with hypoglycaemia were diagnosed with HH. The HH group had a lower median (IQR) glucose level on admission compared to the non-HH group (p < 0.001). The median (IQR) cost of stay was higher in the HH group (p < 0.001). In the HH group, the GIRmax was significantly correlated with cost of stay (p < 0.001). GIRmax predicted a cost of stay > £9140 with an area under the ROC curve of 0.956. GIRmax > 13.9 mg/kg/min predicted admission cost > £9140 with 86% sensitivity and 93% specificity.Conclusion: Transient neonatal HH was associated with a higher length and cost of stay in infants admitted for hypoglycaemia. The GIRmax can predict the length and cost of stay. What is Known: • Neonatal hypoglycaemia is the leading cause of term and late preterm neonatal admissions. • Hyperinsulinism (HH) is the commonest cause of persistent hypoglycaemia, and delay in the diagnosis and management can have a detrimental impact on long-term development. What is New: • We have demonstrated prior to NICU admission that blood glucose concentrations were lower in infants with HH compared to those without. • The maximum GIR had a stronger correlation with total length and cost of hospital stay compared to insulin levels in HH infants.

Prevalence and safety of diazoxide in the neonatal intensive care unit

OBJECTIVE

Diazoxide is used to treat infants with persistent hypoglycemia, but the prevalence of its use and adverse effects are not well described. We report demographic and clinical characteristics of infants treated with diazoxide in neonatal intensive care units (NICUs).

STUDY DESIGN

Retrospective cohort study of infants 24-41 weeks' gestation admitted to 392 NICUs from 1997-2016, comparing characteristics between hypoglycemic infants exposed/not exposed to diazoxide. For diazoxide courses > 1 day, we report percentages of infants starting diuretics and/or developing new ventilator/oxygen requirement during therapy.

RESULTS

Among 1,249,466 infants, 185,832 had hypoglycemia; 1066/185,832 (0.57%) received diazoxide. Diazoxide use increased over time (P = 0.001). Infants receiving diazoxide varied from 0-14.9% among centers. New diuretic courses were associated with 91/664 (14%), and new oxygen or ventilator requirement during therapy was associated with 64/556 (12%) and 34/647 (5%), respectively.

CONCLUSIONS

Diazoxide use in NICU settings has increased over time. Infants receiving diazoxide commonly received diuretics.

Sirolimus-Induced Hepatitis in Two Patients with Hyperinsulinemic Hypoglycemia

Sirolimus has been reported to be effective in the treatment of the diffuse form of congenital hyperinsulinism (CHI), unresponsive to diazoxide and octreotide, without causing severe side effects. Two newborns with CHI due to homozygous ABCC8 gene mutations were started on sirolimus aged 21 and 17 days, due to lack of response to medical treatment. A good response to sirolimus was observed. At follow-up after ten and two months of treatment, liver enzymes were found to be increased [serum sirolimus level 1.4 ng/mL (normal range: 5-15), aspartate aminotransferase (AST): 298U/L, alanine aminotransferase (ALT): 302U/L and serum sirolimus level: 9.9 ng/mL, AST: 261U/L, ALT: 275U/L, respectively]. In Case 1, discontinuation of the drug resulted in normalization of liver enzymes within three days. Two days after normalization, sirolimus was restarted at a lower dose, which resulted in a repeated increase in transferases. In Case 2, a reduction of sirolimus dose caused normalization of liver enzymes within ten days. When the dose was increased, enzymes increased within three days. Sirolimus was discontinued in both cases. The rapid normalization of liver enzyme levels after sirolimus withdrawal or dose reduction; elevation of transaminases after restart or dose increase and rapid normalization after sirolimus withdrawal were findings strongly suggestive of sirolimus-induced hepatitis. To the best of our knowledge, this is the first report of sirolimus-induced hepatitis in CHI. Sirolimus is a promising drug for CHI patients who are unresponsive to medical treatment, but physicians should be vigilant for adverse effects on liver function.

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.

Gut microbiome response to short-term dietary interventions in reactive hypoglycemia subjects

BACKGROUND

Reactive hypoglycemia is a metabolic disorder that provokes severe hypoglycemic episodes after meals. Over recent years, the gut microbiota has been recognized as potential target for the control of metabolic diseases, and the possibility to correct gut microbiota dysbioses through diet, favouring the recovery of metabolic homeostasis, has been considered.

METHODS

We investigate the impact of 2 short-term (3-day) nutritional interventions, based on the macrobiotic Ma-Pi 2 diet and a control Mediterranean diet, on the structure and functionality of the gut microbiota in 12 patients affected by reactive hypoglycemia. The gut microbiota composition was characterized by next-generation sequencing of the V3 to V4 region of the 16S rRNA gene, and the ecosystem functionality was addressed by measuring the faecal concentration of short-chain fatty acids (SCFAs). In order to measure the short-term physiological gut microbiota fluctuation, the microbiomes of 7 healthy people were characterized before and after 3 days of constant diet.

RESULTS

While no convergence of the gut microbiota compositional profiles was observed, a significant increase in SCFA faecal levels was induced only in the Ma-Pi 2 diet group, suggesting the potential of this diet to support a short-term functional convergence of the gut microbiota, regardless of the individual compositional layout.

CONCLUSIONS

The Ma-Pi 2 diet, with its high fibre load, was effective in increasing the production of SCFAs by the gut microbiota. Because these metabolites are known for their ability to counterbalance the metabolic deregulation in persons with glucose impairment disorders, their increased bioavailability could be of some relevance in reactive hypoglycemia.

Attenuation of Insulin Action by an Allosteric Insulin Receptor Antibody in Healthy Volunteers

BACKGROUND

XOMA 358 (X358) is a fully human monoclonal antibody to the insulin receptor that acts as a negative allosteric modulator of insulin signaling. It is being developed as a novel treatment of hyperinsulinemic hypoglycemia. This report describes pharmacokinetic (PK) and pharmacodynamic (PD) data from a first-in-human clinical trial.

METHODS

A double-blind, placebo-controlled, single-ascending-dose study was performed with 29 healthy adult males randomized to intravenous infusion of placebo or X358 at 0.1-, 0.3-, 1-, 3-, 6-, or 9-mg/kg dose levels. The primary objective was to assess safety and tolerability, and secondary objectives included PK and PD analyses. A short insulin tolerance test (ITT) was implemented in the 3- to 9-mg/kg dose cohorts at baseline and postinfusion.

RESULTS

There were no deaths, serious adverse events (AEs), or subject discontinuations due to AEs. There were no clinically meaningful safety findings. X358 exhibited dose-proportional PK with a half-life of 21 days. Dose-dependent elevations of circulating insulin levels, likely related to reduced insulin clearance via monoclonal antibody action at receptors, represented a sensitive biomarker of X358 exposure. X358-dependent increases in postprandial glucose levels and fasting homeostatic model assessment of insulin resistance values were observed and persisted for at least 1 week at the higher dose levels. In all the ITT cohorts, the slope for glucose lowering was substantially attenuated after X358 infusion of a similar magnitude, but with increasing duration with rising dose level.

CONCLUSION

Single X358 infusions were well tolerated and resulted in a dose-dependent reduction in insulin sensitivity. Clinical development of X358 in hyperinsulinemic, hypoglycemic conditions is proceeding.

Clinical practice guidelines for congenital hyperinsulinism

Congenital hyperinsulinism is a rare condition, and following recent advances in diagnosis and treatment, it was considered necessary to formulate evidence-based clinical practice guidelines reflecting the most recent progress, to guide the practice of neonatologists, pediatric endocrinologists, general pediatricians, and pediatric surgeons. These guidelines cover a range of aspects, including general features of congenital hyperinsulinism, diagnostic criteria and tools for diagnosis, first- and second-line medical treatment, criteria for and details of surgical treatment, and future perspectives. These guidelines were generated as a collaborative effort between The Japanese Society for Pediatric Endocrinology and The Japanese Society of Pediatric Surgeons, and followed the official procedures of guideline generation to identify important clinical questions, perform a systematic literature review (April 2016), assess the evidence level of each paper, formulate the guidelines, and obtain public comments.

A Novel Homozygous Mutation in the KCNJ11 Gene of a Neonate with Congenital Hyperinsulinism and Successful Management with Sirolimus

Congenital hyperinsulinism (CHI) is the most common cause of neonatal persistent hypoglycemia caused by mutations in nine known genes. Early diagnosis and treatment are important to prevent brain injury. The clinical presentation and response to pharmacological therapy may vary depending on the underlying pathology. Genetic analysis is important in the diagnosis, treatment, patient follow-up, and prediction of recurrence risk within families. Our patient had severe hypoglycemia and seizure following birth. His diagnostic evaluations including genetic testing confirmed CHI. He was treated with a high-glucose infusion, high-dose diazoxide, nifedipine, and glucagon infusion. A novel homozygous mutation (p.F315I) in the KCNJ11 gene, leading to diazoxide-unresponsive CHI, was identified. Both parents were heterozygous for this mutation. Our patient's clinical course was complicated by severe refractory hypoglycemia; he was successfully managed with sirolimus and surgical intervention was not required. Diazoxide, nifedipine, and glucagon were discontinued gradually following sirolimus therapy. The patient was discharged at 2 months of age on low-dose octreotide and sirolimus. His outpatient clinical follow-up continues with no episodes of hypoglycemia. We present a novel homozygous p.F315I mutation in the KCNJ11 gene leading to diazoxide-unresponsive CHI in a neonate. This case illustrates the challenges associated with the diagnosis and management of CHI, as well as the successful therapy with sirolimus.