Susann Empting

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.

Clinical and Genetic Evaluation of Patients with KATP Channel Mutations from the German Registry for Congenital Hyperinsulinism

Congenital hyperinsulinism (CHI) causes hypoglycemia due to irregular insulin secretion. In infants, a rapid diagnosis and appropriate management to avoid severe hypoglycemia is mandatory. CHI is a heterogeneous condition at the clinical and genetic level, and disease-causing genes have been identified in about half of the patients. The majority of mutations have been identified in the ABCC8 and KCNJ11 genes encoding subunits of the KATP channel responsible for two distinct histological forms. The diffuse form is caused by autosomal recessive or dominant inherited mutations, whereas the focal form is caused by a paternally transmitted recessive mutation and a second somatic event. We report on an unselected cohort of 136 unrelated patients from the German CHI registry. Mutations in either the ABCC8 or KCNJ11 gene were identified in 61 of these patients (45%). In total, 64 different mutations including 38 novel ones were detected in this cohort. We observed biparental (recessive) inheritance in 34% of mutation-positive patients, dominant inheritance in 11% and paternal transmission of a mutation associated with a focal CHI type in 38%. In addition, we observed inheritance patterns that do not exactly follow the classical recessive or dominant mode, further adding to the genetic complexity of this disease.

Visualization of the focus in congenital hyperinsulinism by intraoperative sonography

In surgery for focal congenital hyperinsulinism (CHI), the identification and complete resection of the focus without collateral damage is of utmost importance. In a pilot study we applied intra-abdominal high-frequency sonography during surgery for focal CHI in 2 infants. The focus could be identified, its relation to the pancreatic and common bile duct could be shown, and the typical octopus-like tentacles could be demonstrated. In one case the resection was successful; in the other it was not. These preliminary results suggest that intraoperative sonography could be a valuable tool in the surgical therapy of focal CHI and warrants further evaluation in a clinical study.

A Multicenter Experience with Long-Acting Somatostatin Analogues in Patients with Congenital Hyperinsulinism

Background/Aims: Congenital hyperinsulinism (CHI) is a rare disease characterized by recurrent severe hypoglycemia. In the diffuse form of CHI, pharmacotherapy is the preferred choice of treatment. Long-acting somatostatin analogues have been used in children as off-label medication. However, the efficacy, outcomes, and adverse effect profiles of long-acting somatostatin analogues have not been described in multicentered studies. The aim of this retrospective study is to summarize the experience with long-acting somatostatin analogues in a large group of children with CHI. Methods: Data were obtained retrospectively from 27 patients with CHI who received long-acting somatostatin analogues in 6 different centers in Europe. These included information on glycemic stability, auxology, and adverse effect profile in clinical follow-up assessments. Results: Blood glucose control improved in most patients (89%). No life-threatening side effects occurred. Thirteen patients (48%) experienced side effects; in 3 patients (11%), the side effects were the main reason for discontinuation of the treatment. The most frequent side effect was elevated liver enzymes (n = 10, 37%). Conclusion: Long-acting somatostatin analogues are effective in glycemic control of patients with CHI. However, in 37% of all patients increased liver enzymes were observed. It is important to monitor liver function in all patients receiving long-acting somatostatin analogue therapy.

Formal Neurocognitive Testing in 60 Patients with Congenital Hyperinsulinism

Background: Congenital hyperinsulinism (CHI) is hallmarked by persistent hypoketotic hypoglycemia in infancy. In the majority of all patients, CHI is caused by mutations in the KATP channel genes ABCC8 and KCNJ11, but other genes in the insulin-regulatory pathway have also been described. Repeated episodes of hypoglycemia include an increased risk of seizures and intellectual disability. So far, controlled psychometric studies on cognitive, motor, speech, and social-emotional outcome of CHI patients are missing. Until now, neurodevelopmental long-term outcome in CHI patients has only been measured by questionnaires, self-, parental-, or caregiver-administered instruments. Methods: This is a prospective study of 60 patients (median age 3.3 years, range 3 months to 57 years): 48 with a diffuse, 9 with a focal, and 3 with an atypical histology. Neurodevelopmental outcome was assessed using standardized psychological tests and questionnaires. Results: 28 of 60 patients showed developmental delay (46.7%). 9 of 57 patients had cognitive deficits (15.8%), 7 of 26 patients had speech problems (26.9%), and 17 of 44 patients had motor problems (38.6%). In 5 of 53 patients, social-emotional problems were reported. Outcome and the underlying genetic defect were not correlated. Conclusions: Motor problems seem to be prominent in CHI patients. Despite a high incidence of developmental delay, a permanent cognitive defect was only detectable in 9 of 58 patients.

Therapy monitoring in congenital adrenal hyperplasia by dried blood samples.

Abstract Careful monitoring of the therapy is crucial for patients with congenital adrenal hyperplasia (CAH) in order to prevent the effects of increased androgen production as well as life-threatening salt-wasting crisis. The key metabolite, 17α-hydroxyprogesterone (17-OHP) can be detected in serum, saliva or dried blood. In clinical practice there are challenges due to discomfort of venous blood sampling and complicated retrieval of saliva during infancy. Furthermore, the immunoassay method is limited in its specificity due to cross-reactions. In this observational study we prospectively examined over a period of 5 years, 20 patients with CAH due to 21-hydroxylase deficiency using standard immunoassays for serum samples (radioimmunoassay and enzyme immunoassay) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) in dried blood spots. Bland-Altman plots show goodness of agreement between both the methods for the desirable therapeutic concentration range of 17-OHP. LC-MS/MS is characterized by a high accuracy in the therapeutic concentration range of 17-OHP <100 nmol/L (r=0.91). Dried blood samples are convenient and reliable specimen for 17-OHP measured by LC-MS/MS. This method could be used for home monitoring of hydrocortisone replacement therapy both in salt-waster and simple virilizer CAH.

Planungsunterstützung für Pankreasoperationen bei Hyperinsulinismus von Kindern

Auf Basis von sechs PET/CT-Datensatzen des Pankreas wird eine Computerunterstutzung fur die Teilresektion der Bauchspeicheldr use (Pankreas) bei fokalem Hyperinsulinismus von Kindern entwickelt. Ziel ist es, die Lokalisation des krankhaften Fokus im Pankreasgewebe praoperativ dreidimensional zu visualisieren, um so die Sicherheit des Eingriffs zu erhohen. Die relevanten anatomischen Strukturen werden im CT segmentiert und anschliesend dreidimensional visualisiert. Der im PET erkennbare Fokus wird in diese anatomische 3D-Visualisierung eingeblendet. Es zeigt sich eine klare Erkennbarkeit des Fokus in allen sechs Fallen.