Persistent hyperinsulinemic hypoglycemia of infancy: long-term results

[Electroencephalogram features in children with congenital hyperinsulinism treated according to the international protocol in Russian Federation]

BACKGROUND

Congenital hyperinsulinism (CHI) is a rare life-threatening disease characterised by persistent hypoglycaemia as a result of inappropriate insulin secretion, which can lead to irreversible neurological defects in infants.

AIM

To evaluate neurophysiological characteristics of central nervous system in children with congenital hyperinsulinism treated according to the international protocol in Russian Federation.

MATERIALS AND METHODS

Our retrospective, prospective cohort study included 73 patients who received treatment for CHI according to the current international protocol at different departments of the Almazov National Medical Research Centre from 2017 to 2022. All patients underwent a comprehensive examination, including electroencephalography (EEG).

RESULTS

Among 73 patients with CHI, 35% (23) had focal form of the disease, 65% had non-focal form (49% (39) - diffuse form, 16% (11) - atypical form). All patients with focal form of CHI had a recovery as an outcome.Analysing the EEG data we found that paroxysmal activity was recorded in 23 patients (32%), 50 patients did not have paroxysmal activity (68%). Diffuse changes were observed in 47 patients (64%), whereas 26 patients (36%) were absent of it. By constructing Kaplan-Meier curves we found that the alpha rhythm is formed significantly (p=0.026) earlier in patients with a focal form of CHI.

CONCLUSION

CHI patients treated according to the international guidelines in Russian Federation show rather positive neurological outcome. We established that alpha rhythm earliest formation is associated with focal form of CHI.

Hyperinsulinemic hypoglycemia in adolescents: case report and systematic review

BACKGROUND

Hyperinsulinemic hypoglycemia is the most common cause of severe and persistent hypoglycemia in neonates and children. It is a heterogeneous condition with dysregulated insulin secretion, which persists in the presence of low blood glucose levels.

CASE PRESENTATION

We report a case of a 15 year-old male with hyperinsulinemic hypoglycemia, who underwent a subtotal pancreatectomy after inadequate response to medical therapy. Pathological examination was positive for nesidioblastosis (diffuse β-cell hyperplasia by H-E and immunohistochemical techniques). The patient's blood glucose levels normalized after surgery and he remains asymptomatic after 1 year of follow-up. The systematic review allowed us to identify 41 adolescents from a total of 205 cases reported in 22 manuscripts, from a total of 454 found in the original search done in PubMed and Lilacs.

CONCLUSIONS

Although very well reported in children, hyperinsulinemic hypoglycemia can occur in adolescents or young adults, as it happens in our reported case. These patients can be seen, treated and reported by pediatricians or adult teams either way due to the wide age range used to define adolescence. Most of them do not respond to medical treatment, and subtotal distal pancreatectomy has become the elected procedure with excellent long-term response in the vast majority.

Somatostatin analogues for the treatment of hyperinsulinaemic hypoglycaemia

Hyperinsulinaemic hypoglycaemia (HH) is a biochemical finding of low blood glucose levels due to the dysregulation of insulin secretion from pancreatic β-cells. Under normal physiological conditions, glucose metabolism is coupled to β-cell insulin secretion so that blood glucose levels are maintained within the physiological range of 3.5-5.5 mmol/L. However, in HH this coupling of glucose metabolism to insulin secretion is perturbed so that insulin secretion becomes unregulated. HH typically occurs in the neonatal, infancy and childhood periods and can be due to many different causes. Adults can also present with HH but the causes in adults tend to be different. Somatostatin (SST) is a peptide hormone that is released by the delta cells (δ-cells) in the pancreas. It binds to G protein-coupled SST receptors to regulate a variety of location-specific and selective functions such as hormone inhibition, neurotransmission and cell proliferation. SST plays a potent role in the regulation of both insulin and glucagon secretion in response to changes in glucose levels by negative feedback mechanism. The half-life of SST is only 1-3 min due to quick degradation by peptidases in plasma and tissues. Thus, a direct continuous intravenous or subcutaneous infusion is required to achieve the therapeutic effect. These limitations prompted the discovery of SST analogues such as octreotide and lanreotide, which have longer half-lives and therefore can be administered as injections. SST analogues are used to treat different forms of HH in children and adults and therapeutic effect is achieved by suppressing insulin secretion from pancreatic β-cells by complex mechanisms. These treatments are associated with several side effects, especially in the newborn period, with necrotizing enterocolitis being the most serious side effect and hence SS analogues should be used with extreme caution in this age group.

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.

Genotype and phenotype correlations in Iranian patients with hyperinsulinaemic hypoglycaemia

Background

Hyperinsulinaemic hypoglycaemia (HH) is a group of clinically and genetically heterogeneous disorders characterized by unregulated insulin secretion. Abnormalities in nine different genes (ABCC8, KCNJ11, GLUD1, GCK, HADH, SLC16A1, HNF4A, UCP2 and HNF1A) have been reported in HH, the most common being ABCC8 and KCNJ11. We describe the genetic aetiology and phenotype of Iranian patients with HH.

Methods

Retrospective clinical, biochemical and genetic information was collected on 23 patients with biochemically confirmed HH. Mutation analysis was carried out for the ATP-sensitive potassium (K_ATP) channel genes (ABCC8 and KCNJ11), GLUD1, GCK, HADH and HNF4A.

Results

78 % of the patients were identified to have a genetic cause for HH. 48 % of patients had mutation in HADH, whilst ABCC8/KCNJ11 mutations were identified in 30 % of patients. Among the diazoxide-responsive patients (18/23), mutations were identified in 72 %. These include two novel homozygous ABCC8 mutations. Of the five patients with diazoxide-unresponsive HH, three had homozygous ABCC8 mutation, one had heterozygous ABCC8 mutation inherited from an unaffected father and one had homozygous KCNJ11 mutation. 52 % of children in our cohort were born to consanguineous parents. Patients with ABCC8/KCNJ11 mutations were noted to be significantly heavier than those with HADH mutation (p = 0.002). Our results revealed neurodevelopmental deficits in 30 % and epilepsy in 52 % of all patients.

Conclusions

To the best of our knowledge, this is the first study of its kind in Iran. We found disease-causing mutations in 78 % of HH patients. The predominance of HADH mutation might be due to a high incidence of consanguineous marriage in this population. Further research involving a larger cohort of HH patients is required in Iranian population.

Glucose metabolism and neurological outcome in congenital hyperinsulinism

Advances in imaging and surgical techniques allow a complete cure for children with focal-type congenital hyperinsulinism (CHI). In contrast, management of diffuse-type CHI remains a matter of controversy. To prevent hypoglycemic brain damage, extensive surgery has been recommended in the past, resulting in diabetes. On the basis of 2 data sets of patients with congenital hyperinsulinism, the German registry for CHI with 235 patients (ages 1 day to 19 years) and the diabetes treatment register (Diabetes Patienten-Verlaufsdokumentationssystem initiative), a follow-up study was initiated for diabetes mellitus and the intellectual and physical development as well as motor function. In our ongoing study, we investigated 20 patients with CHI (12 male, mean ages 9.9 years). Six of 20 patients had undergone subtotal pancreatectomy. In early infantile development (0-3 years) we observed a trend to motor and speech delay. In early childhood (2.5-7 years) there appeared a trend to an advantage of results of nonverbal tasks compared with verbal tasks. Before 1990 most patients (∼75%) were treated by subtotal pancreatectomy; since 2000, a more conservative approach is obvious (4/68). All patients with diabetes (n = 25) developed the condition after undergoing subtotal pancreatectomy. No spontaneous manifestation of diabetes was noted before adulthood. There was a wide range of age (0-17.7 years) at manifestation indicating a long period during which glucose tolerance is compensated. Compared with >40.000 children with type 1 diabetes mellitus from the Diabetes Patienten-Verlaufsdokumentationssystem registry, we found significant differences with a tendency for being overweight as well as small stature. Mean daily insulin dose and HbA1c was comparable in both groups.

Congenital hyperinsulinism and glucose hypersensitivity in homozygous and heterozygous carriers of Kir6.2 (KCNJ11) mutation V290M mutation: K(ATP) channel inactivation mechanism and clinical management

OBJECTIVE

The ATP-sensitive K(+) channel (K(ATP)) controls insulin secretion from the islet. Gain- or loss-of-function mutations in channel subunits underlie human neonatal diabetes and congenital hyperinsulinism (HI), respectively. In this study, we sought to identify the mechanistic basis of K(ATP)-induced HI in two probands and to characterize the clinical course.

RESEARCH DESIGN AND METHODS

We analyzed HI in two probands and characterized the course of clinical treatment in each, as well as properties of mutant K(ATP) channels expressed in COSm6 cells using Rb efflux and patch-clamp methods.

RESULTS

We identified mutation V290M in the pore-forming Kir6.2 subunit in each proband. In vitro expression in COSm6 cells supports the mutation resulting in an inactivating phenotype, which leads to significantly reduced activity in intact cells when expressed homomerically, and to a lesser extent when expressed heteromerically with wild-type subunits. In one heterozygous proband, a fluoro-DOPA scan revealed a causal focal lesion, indicating uniparental disomy with loss of heterozygosity. In a second family, the proband, homozygous for the mutation, was diagnosed with severe diazoxide-unresponsive hypersinsulinism at 2 weeks of age. The patient continues to be treated successfully with octreotide and amlodipine. The parents and a male sibling are heterozygous carriers without overt clinical HI. Interestingly, both the mother and the sibling exhibit evidence of abnormally enhanced glucose tolerance.

CONCLUSIONS

V290M results in inactivating K(ATP) channels that underlie HI. Homozygous individuals may be managed medically, without pancreatectomy. Heterozygous carriers also show evidence of enhanced glucose sensitivity, consistent with incomplete loss of K(ATP) channel activity.

Laparoscopic vs open pancreatectomy for persistent hyperinsulinemic hypoglycemia of infancy

BACKGROUND

Persistent hyperinsulinemic hypoglycemia of infancy (PHHI) is considered the most common cause of persistent neonatal hypoglycemia. The aim of this study is to compare laparoscopic pancreatectomy with open pancreatectomy for PHHI in one center regarding feasibility, safety, and effectiveness.

METHODS

A retrospective chart review was conducted for patients managed for PHHI with either laparoscopic or open pancreatectomy for the period from 2001 to 2007 at King Faisal Specialist Hospital and Research Center (Riyadh, Saudi Arabia). Demographic and clinical data were retrieved. Continuous variables were reported as means, and categorical variables were reported as proportions for each group. Means were compared using Student's t test, and proportions were compared using chi(2) test or Fisher's Exact test where appropriate. A P value less than .05 was considered statistically significant. The study proposal was approved by the Clinical Research Committee and the Research Ethics Committee at our institution.

RESULTS

Eighteen patients were managed with pancreatectomy for PHHI for that period: 10 laparoscopic and 8 open. The 2 groups were comparable regarding age and weight at surgery, sex, procedure duration, hospital stay postoperatively, need for reoperation, and development of diabetes mellitus and mental delay. Extent of resection was significantly higher in the open group (P value = .02), and the laparoscopic group was fed significantly earlier (P value = .001). The mean follow-up for the laparoscopic and the open groups were 20.4 months and 46 months, respectively (P value = .004).

CONCLUSIONS

Laparoscopic pancreatectomy for PHHI is safe and feasible. Our data suggest its effectiveness compared to the open approach.

Laparoscopic pancreatectomy for persistent hyperinsulinemic hypoglycemia of infancy

BACKGROUND

Persistent hyperinsulinemic hypoglycemia of infancy (PHHI) is considered the most common cause of persistent neonatal hypoglycemia. Management of PHHI involves use of medical agents and its failure is an indication of surgical intervention. Traditionally, an open pancreatectomy was the standard of care but recently laparoscopic pancreatectomy was described. We report our experience with laparoscopic pancreatectomy for PHHI for the period from March 2004 to February 2008.

METHODS

A retrospective chart review was conducted for patients managed for PHHI with laparoscopic pancreatectomy for that period. Demographic and clinical data were retrieved. Descriptive data were generated, and SPSS version 10 statistical package (SPSS, Chicago, Ill) was used.

RESULTS

Twelve patients diagnosed with PHHI were managed with laparoscopic pancreatectomy for that period. Median age at procedure was 11.5 months (range, 0.5-89 months). Median extent of pancreatectomy was 90% (range, 85%-95%). There were 2 (16%) conversions to open technique. One patient (8%) required reoperation 3 months after the procedure. Patients were followed up for a median of 23.5 months (range, 3-48 months). Four (33%) were euglycemic with no medications. Three patients remained on octreotide postoperatively to be euglycemic, and 3 patients needed a combination of octreotide and diazoxide. One patient remained euglycemic for 10 months then started on octreotide because of recurrence of hypoglycemia. One patient remained hypoglycemic postoperatively and required reoperation 3 months later to control symptoms. He became diabetic 4 months after reoperation on insulin.

CONCLUSIONS

Our data suggest that laparoscopic pancreatectomy for medically unresponsive PHHI is feasible and safe. Longer follow-up is needed to ascertain effectiveness.

Persistent Hyperinsulinaemic Hypoglycaemia of Infancy in 43 Children: Long-term Clinical and Surgical Follow-up

OBJECTIVE

To describe the clinical, surgical, biochemical, radiological and electrophysiological features of 43 Saudi children with persistent hyperinsulinaemic hypoglycaemia of infancy (PHHI) who have been followed since 1983.

METHODS

Data from 43 patients were retrospectively analysed. PHHI was diagnosed on the basis of high intravenous glucose requirement, high insulin to glucose ratio, negative urinary ketones and normal tandem mass spectrometry. The patients were assessed radiologically by brain magnetic resonance imaging and/or computed tomography and electrophysiologically by brain stem auditory evoked potential, visual evoked response and electroencephalogram. Patients who failed medical therapy received near total pancreatectomy.

RESULTS

The patients were severely hypoglycaemic and intolerant to fast. Hypoglycaemic convulsion was the most commonly presenting complaint. Eighteen patients were developmentally delayed and 14 of them had brain atrophy. All patients, except nine, did not respond to medical treatment and underwent surgery. Four pancreatectomized patients developed diabetes and two had malabsorption. One baby had 180 cm resection of gangrenous bowel most likely secondary to octreotide. No common bile duct injury was encountered. One patient was treated medically during childhood and developed diabetes and gained weight during adolescence.

CONCLUSION

PHHI is a relatively common and serious disease among Saudi children. Early intervention is necessary to avoid neurological damage in patients who are severely hypoglycaemic and unresponsive to medical therapy. Surgically and probably medically treated patients are at a high risk of developing diabetes, which could be the natural outcome of this disease. Care and spending time during surgery to visualize the common bile duct help in avoiding its injury.

Hiperinsulinismo congénito. Revisión de 22 casos

INTRODUCTION

Congenital hyperinsulinism (CHI) is the most common cause of recurrent episodes of hypoglycemia in early childhood and consists of a group of distinct genetic disorders causing dysregulation of insulin secretion.

OBJECTIVE

To review the presentation, management and outcome of patients with CHI attended at our hospital.

MATERIAL AND METHODS

A retrospective review of all patients diagnosed with CHI between 1982 and 2004 was performed. Data were collected on age, gender, clinical presentation, medical and surgical management, and complications.

RESULTS

Twenty-two patients were identified. Notable features were early symptom onset in 80 %, pancreatectomy in 72 %, and neurological sequels in 28 % (abnormal neurodevelopment in 22 % and epilepsy in 13 %).

CONCLUSIONS

The presentation, management and outcome in our patients were similar to those in other series, indicating the need for early diagnosis and treatment to avoid neurological sequels.

Neurodevelopment after neonatal hypoglycemia: a systematic review and design of an optimal future study

OBJECTIVE

Our goal was to assess the effect of episodes of neonatal hypoglycemia on subsequent neurodevelopment.

METHODS

We searched Medline and Embase for cohort studies on subsequent neurodevelopment after episodes of hypoglycemia in the first week of life. Reference lists of available studies were reviewed, and content experts were contacted for additional studies. Included studies were selected and appraised for methodologic quality by 2 reviewers. Methodologic quality was assessed according to well-accepted criteria for prognostic studies. Eventually, all studies were given an overall quality score: poor, moderate, or high quality. Studies in the latter 2 categories were considered for quantitative data analysis.

RESULTS

Eighteen eligible studies were identified. The overall methodologic quality of the included studies was considered poor in 16 studies and high in 2 studies. Pooling of results of the 2 high-quality studies was deemed inappropriate because of major clinical and methodologic heterogeneity. None of the studies provided a valid estimate of the effect of neonatal hypoglycemia on neurodevelopment. Building on the strengths and weaknesses of existing studies, we developed a proposal for an "optimal" future study design.

CONCLUSIONS

Recommendations for clinical practice cannot be based on valid scientific evidence in this field. To assess the effect of neonatal hypoglycemia on subsequent neurodevelopment, a well-designed prospective study should be undertaken. We submit a design for a study that may answer the still-open questions.

Effects of hypoglycemia on developmental outcome in children with congenital hyperinsulinism

Children with congenital hyperinsulinism are at risk for recurring, severe episodes of hypoglycemia that can cause seizures, brain damage, and developmental delay. To assess the frequency of permanent brain damage in this disorder, we carried out a telephone survey of 68 children who presented to The Children's Hospital of Philadelphia between 1980 and 2000. One third of the group had some degree of developmental delay. Those presenting in the first week of life and those with medically unresponsive hyperinsulinism were more likely to have delays. Early recognition and control of hypoglycemia are essential for preventing developmental delay in these children.

Hyperinsulinisme persistant du nouveau-né et du nourrisson : traitement chirurgical des lésions pancréatiques focales dans 60 cas

Congenital hyperinsulinism of infancy is a severe disease that leads to important brain damage. Two different forms of the disease have been identified by pathologists: a diffuse and a focal form. A specific genetic anomaly identified in focal forms has never been described in diffuse ones. However, for most of authors, failure of medical treatment results in near-total pancreatectomy in all cases, which ends in diabetus. The aim of this retrospective study was to assess the results of elective partial pancreatectomy performed in 60 cases of focal form of hyperinsulinism over the last 18 years. Fifty-eight patients were cured with euglycemia at both fasting and hyperglycaemic tests without insulin-dependent diabetes mellitus. One patient is still in hypoglycaemia from unrecognized lesion; insulin-dependent diabetes mellitus occurred in one case nine years after surgery (a near-total pancreatectomy has been performed because of unknown focal form, in 1985).

Central nervous system hyperexcitability associated with glutamate dehydrogenase gain of function mutations

OBJECTIVE

To describe seizure phenotypes associated with the hyperinsulinism/hyperammonemia syndrome (HI/HA), which is caused by gain of function mutations in the enzyme glutamate dehydrogenase (GDH).

STUDY DESIGN

A retrospective review of records of 14 patients with HI/HA.

RESULTS

Nine patients had seizures as the first symptom of HI/HA, and six had seizures in the absence of hypoglycemia. No electroencephalogram (EEG) background abnormalities were identified. In four patients, EEG recordings during seizures in the setting of normal blood glucose contained generalized epileptiform discharges. EEGs of three of these patients showed 0.5- to 2-second generalized irregular spike-and-wave discharge at 3 to 6 Hz corresponding to eye blinks, eye rolling, or staring. The EEG of the fourth patient consisted of 20 seconds of generalized regular spike-and-wave discharge at 3 Hz in the clinical context of staring and unresponsiveness. In two patients, seizure control worsened with carbamezapine or oxcarbezapine treatment.

CONCLUSIONS

In patients with HI/HA, generalized seizures are common and can occur in the absence of hypoglycemia. The drugs carbamazepine and oxcarbazepine should be used with caution for treatment. Pathogenesis of epilepsy in these patients may be related to effects of GDH mutations in the brain, perhaps in combination with effects of recurrent hypoglycemia and chronic hyperammonemia.

Persistent hyperinsulinemic hypoglycemia of infancy: long-term outcome following subtotal pancreatectomy

BACKGROUND

Persistent hyperinsulinemic hypoglycemia of infancy (PHHI) is the most common cause of persistent hypoglycemia in infants. The current standard treatment is subtotal pancreatectomy (Px). However, the long-term outcome following surgery needs further attention.

METHODS

We analyzed 10 children (7 M, 3 F) with PHHI who underwent partial (65-80%) and subtotal (81-95%) Px. Follow-up ranged from 2 to 9.4 yr (mean = 4.2 yr). We divided them into 2 groups based upon the age at onset of hypoglycemia: early (< 1 mo) and late (> or = 1 mo).

RESULTS

The seven patients in the early-onset group underwent 85-95% Px between ages of 18 d and 3 mo. Three of them initially treated by 85-90% Px had persistent hypoglycemia postoperatively. Two out of three required a 2nd operation with 95% Px for controlling hypoglycemia, though both still had persistent hypoglycemia and required medication to control blood glucose. The remaining four had 95% Px and had maintained euglycemia postoperatively. One patient developed diabetes 6 yr after surgery. Six of seven patients had delayed development and subnormal IQ. Three patients of the late-onset group (3 mo, 6 mo and 4 yr) underwent partial Px (80%, 65% and 65%, respectively) and maintained euglycemia postoperatively. Despite 65% Px, one developed diabetes 3 yr after surgery.

CONCLUSIONS

These results suggest that children with early-onset hypoglycemia have more severe hyperinsulinism than those with late-onset hypoglycemia. The former require 95% Px for maintaining euglycemia, but long-term complications with diabetes may be common. In contrast, the latter require lower percentage Px which may reduce the incidence of diabetes in the future.