Search

Objective Genetic aetiology remains unknown in up to 50% of patients with persistent hyperinsulinaemic hypoglycaemia (HH). Several syndromes are associated with HH. We report Rubinstein–Taybi syndrome (RSTS) as one of the possible causes of persistent HH. Early diagnosis and treatment of HH is crucial to prevent hypoglycaemic brain injury. Design Four RSTS patients with HH were retrospectively analysed. Methods Genetic investigations included next-generation sequencing-based gene panels and exome sequencing. Clinical characteristics, metabolic profile during hypoglycaemia and treatment were reviewed. Results Disease-related EP300 or CREBBP variants were found in all patients, no pathogenic variants were found in a panel of genes associated with non-syndromic HH. Two patients had classic manifestations of RSTS, three had choanal atresia or stenosis. Diagnosis of HH varied from 1 day to 18 months of age. One patient was unresponsive to treatment with diazoxide, octreotide and nifedipine, but responded to sirolimus. All required gastrostomy feeding. Conclusions Given the rarity of RSTS (1:125 000) and HH (1:50 000), our observations indicate an association between these two conditions. We therefore recommend that clinicians should be vigilant in screening for HH in symptomatic infants with RSTS. In children with an apparent syndromic form of HH, RSTS should be considered in the differential diagnosis.

Aims To analyse time-trends in BMI, obesity and cardiometabolic risk in adults with type 1 diabetes (T1DM) from the Diabetes Prospective Follow-up registry DPV. Methods Data from 62,519 individuals with T1DM (age ≥ 18 years, BMI ≥ 18.5 kg/m2) were analysed. Multivariable regression models were used to determine time-trends in BMI, obesity and cardiometabolic risk and to identify predictors for increasing BMI. Results were compared to the NCD Risk Factor Collaboration (NCD-RisC) data for Germany. Results Between 1999 and 2018 mean BMI increased from 25.0 kg/m2 to 26.2 kg/m2 in individuals with T1DM. This trend was most pronounced in young and middle-aged individuals (>21–55 years of age) and in those with higher baseline BMI. Insulin dose and diabetes duration were associated with increasing BMI. Between 1999 and 2016, the prevalence of obesity increased 1.8-fold in individuals with T1DM and 1.4-fold among the German population, respectively (NCD-RisC). Approximately 50–70% of individuals with obesity were insufficiently treated for hypertension and/or dyslipidaemia. Conclusion In adults with T1DM the prevalence of obesity is increasing at a faster pace than in the German population. BMI needs to be closely monitored, particularly during young adulthood, and cardiovascular risk factors need to be controlled better to prevent CVD and premature death.

BACKGROUND AND OBJECTIVE: Kabuki syndrome (KS), caused by pathogenic variants in KMT2D or KDM6A, is associated with hyperinsulinaemic hypoglycaemia (HH) in 0.3%-4% of patients. We characterized the clinical, biochemical and molecular data of children with KS and HH compared to children with KS without HH in a multicentre meta-analysis.METHODS: Data of seven new and 17 already published children with KS and HH were compared to 373 recently published KS patients without HH regarding molecular and clinical characteristics.RESULTS: Seven new patients were identified with seven different pathogenic variants in KDM6A (n = 4) or KMT2D (n = 3). All presented with HH on the first day of life and were responsive to diazoxide. KS was diagnosed between 9 months and 14 years of age. In the meta-analysis, 24 KS patients with HH had a significantly higher frequency of variants in KDM6A compared to 373 KS patients without HH (50% vs 11.5%, P < .001), and KDM6A-KS was more likely to be associated with HH than KMT2D-KS (21.8% vs. 3.5%, P < .001). Sex distribution and other phenotypic features did not differ between KS with and without HH.CONCLUSION: The higher incidence of HH in KDM6A-KS compared to KMT2D-KS indicates that KDM6A loss of function variants predispose more specifically to beta cell dysfunction compared to KMT2D variants. As difficulties to assign syndromic characteristics to KS in early infancy often lead to delayed diagnosis, genetic testing for KS should be considered in children with HH, especially in the presence of other extrapancreatic/syndromic features.

In this clinical trial, we investigated the blood glucose (BG)‐lowering effects of 30, 60 and 90 mg dextromethorphan (DXM) as well as 100 mg sitagliptin alone versus combinations of DXM and sitagliptin during an oral glucose tolerance test (OGTT) in 20 men with T2DM. The combination of 60 mg DXM plus 100 mg sitagliptin was observed to have the strongest effect in the OGTT. It lowered maximum BG concentrations and increased the baseline‐adjusted area under the curve for serum insulin concentrations in the first 30 min of the OGTT (mean ± standard deviation 240 ± 47 mg/dl and 8.1 ± 6.1 mU/l/h, respectively) to a significantly larger extent than did 100 mg sitagliptin alone (254 ± 50 mg/dl and 5.8 ± 2.5 mU/l/h, respectively; p < 0.05) and placebo (272 ± 49 mg/dl and 3.9 ± 3.0 mU/l/h, respectively; p < 0.001). All study drugs were well tolerated, alone and in combination, without serious adverse events or hypoglycaemia. Long‐term clinical trials are now warranted to investigate the potential of the combination of 30 or 60 mg DXM and dipeptidyl peptidase‐4 inhibitors in the treatment of individuals with T2DM, in particular as preclinical studies have identified the β‐cell protective properties of DXM.

Background Treatment of severe diffuse congenital hyperinsulinism (CHI) without sufficient response to diazoxide is complicated by the lack of approved drugs. Therefore, patients are often hospitalized long-term or have to undergo pancreatic surgery if episodes of severe hypoglycaemia cannot be prevented. A long-acting somatostatin analogue, octreotide, has been reported to be an effective treatment option that prevents severe hypoglycaemia in children with CHI, and its off-label use is common in CHI. However, octreotide requires continuous i.v. or s.c. infusion or multiple daily injections. Here, we report our experiences with the use of a monthly application of a long-acting somatostatin analogue, lanreotide autogel® (LAN-ATG), in early infancy. Results The mean blood glucose concentration within 7 days before the first LAN-ATG administration were compared to 7 days after the first LAN-ATG administration and increased by 0.75 mmol/L (range 0.39–1.19 mmol/L). In the following weeks intravenous glucose infusions, octreotide, and glucagon treatment could be successfully stopped in all patients 3–20 days after the first LAN-ATG injection without substantial worsening of the hypoglycaemia rate. Increased carbohydrate requirements could be normalized with an average reduction in the carbohydrate-intake of 7 g/kg body weight/d (range 1.75–12.8 g/kg body weight/d). Over a total of 52 treatment months, no serious adverse effects occurred. Conclusion Long-term LAN-ATG treatment improved blood glucose concentrations, lowered the frequency of hypoglycaemia or allowed for normalization of oral carbohydrate intake in infants with CHI younger than 6 months of age. No severe side effects were observed. LAN-ATG might be an alternative treatment option in infants with severe CHI who lack risk factors for necrotizing enterocolitis and are not responding to current treatment regimens as an alternative to surgery after careful individual evaluation.

BACKGROUND During conservative treatment, congenital hyperinsulinism (CHI) can resolve spontaneously. This study describes the hormonal and metabolic profiles in three patients with ABCC8/KCNJ11 mutations in clinical remission. METHODS An age-adapted fasting and oral glucose tolerance test (OGTT) were performed. RESULTS All patients (aged 6-9 years) tolerated age-adapted fasting durations (20, respectively 24 h), without reaching glucose concentrations ≤2.5 mmol/L, nor developing hypoglycemia-related symptoms. Nevertheless, insulin concentrations from all patients exceeded the 90th reference percentile at the end of the fasting test (range: 4.2-15.8 mU/L). During the OGTT, one patient (patient 2; BMI: 23.4 kg/m2; age: 7 years) reached a glucose concentration of 11.4 mmol/L after 2 h (concomitant insulin concentration: 148.3 mU/L). CONCLUSIONS The insulin concentration profiles in CHI patients in apparent clinical remission range from almost complete normalization to persistent, yet attenuated, hypersecretion. The hyperglycemia, detected during the OGTT, must be further monitored.

Background Up to now, only limited data on long-term medical treatment in congenital hyperinsulinism (CHI) is available. Moreover, most of the drugs used in CHI are therefore not approved. We aimed to assemble more objective information on medical treatment in CHI with regard to type and duration, dosage as well as side effects. Methods We searched MEDLINE (from 1947) and EMBASE (from 1988) using the OVID interface for relevant data to evaluate medical treatment in a large cohort of patients with CHI from different clinical centers. Randomized, controlled trials were not available. We evaluated case reports and case series. No language restrictions were made. Results A total number of 619 patients were medically treated and information regarding conservative treatment was available. Drugs used were diazoxide (in 84 % of patients), somatostatin analogues (16 %), calcium channel antagonists (4 %) and glucagon (1 %). Mean dose of diazoxide was 12.5 (±4.3) mg/kg ⋅ d (range 2–60 mg/kg ⋅ d), mean duration of diazoxide treatment until remission was 57 months. Side effects of diazoxide were usually not severe. The causal relation between diazoxide and severe side effects, e.g. heart failure (3.7 %) remains doubtful. Mean dose of octreotide was 14.9 (±7.5) μg/kg ⋅ d (range 2.3–50 μg/kg ⋅ d), of lanreotide 67.3 (±39.8) mg ⋅ month (range 10–120 mg ⋅ month). Mean duration of treatment with somatostatin analogues until remission was 49 months. Frequent side effects included tachyphylaxis and mild gastrointestinal symptoms. The risk of persistent growth deceleration was low (

A hallmark feature of type 1 and type 2 diabetes mellitus is the progressive dysfunction and loss of insulin-producing pancreatic beta cells, and inflammatory cytokines are known to trigger beta cell death. Here we asked whether the anti-oxidant protein DJ-1 encoded by the Parkinson's disease gene PARK7 protects islet cells from cytokine- and streptozotocin-mediated cell death. Wild type and DJ-1 knockout mice (KO) were treated with multiple low doses of streptozotocin (MLDS) to induce inflammatory beta cell stress and cell death. Subsequently, glucose tolerance tests were performed, and plasma insulin as well as fasting and random blood glucose concentrations were monitored. Mitochondrial morphology and number of insulin granules were quantified in beta cells. Moreover, islet cell damage was determined in vitro after streptozotocin and cytokine treatment of isolated wild type and DJ-1 KO islets using calcein AM/ethidium homodimer-1 staining and TUNEL staining. Compared to wild type mice, DJ-1 KO mice became diabetic following MLDS treatment. Insulin concentrations were substantially reduced, and fasting blood glucose concentrations were significantly higher in MLDS-treated DJ-1 KO mice compared to equally treated wild type mice. Rates of beta cell apoptosis upon MLDS treatment were twofold higher in DJ-1 KO mice compared to wild type mice, and in vitro inflammatory cytokines led to twice as much beta cell death in pancreatic islets from DJ-1 KO mice versus those of wild type mice. In conclusion, this study identified the anti-oxidant protein DJ-1 as being capable of protecting pancreatic islet cells from cell death induced by an inflammatory and cytotoxic setting.

In the nervous system, NMDA receptors (NMDARs) participate in neurotransmission and modulate the viability of neurons. In contrast, little is known about the role of NMDARs in pancreatic islets and the insulin-secreting beta cells whose functional impairment contributes to diabetes mellitus. Here we found that inhibition of NMDARs in mouse and human islets enhanced their glucose-stimulated insulin secretion (GSIS) and survival of islet cells. Further, NMDAR inhibition prolonged the amount of time that glucose-stimulated beta cells spent in a depolarized state with high cytosolic Ca(2+) concentrations. We also noticed that, in vivo, the NMDAR antagonist dextromethorphan (DXM) enhanced glucose tolerance in mice, and that in vitro dextrorphan, the main metabolite of DXM, amplified the stimulatory effect of exendin-4 on GSIS. In a mouse model of type 2 diabetes mellitus (T2DM), long-term treatment with DXM improved islet insulin content, islet cell mass and blood glucose control. Further, in a small clinical trial we found that individuals with T2DM treated with DXM showed enhanced serum insulin concentrations and glucose tolerance. Our data highlight the possibility that antagonists of NMDARs may provide a useful adjunct treatment for diabetes.

Background Congenital hyperinsulinaemic hypoglycaemia is characterised by low serum concentrations of ketones, fatty acids, and branched chain aminoacids, and by a requirement for glucose infusion of more than 10 mg/kg per min to maintain euglycaemia. The disorder is caused by physiologically inappropriate insulin secretion. We have recently described a form of hypoglycaemia with a similar metabolic profile, but with undetectable insulin, relatively low glucose requirement, and left-sided hemihypertrophy caused by an activating mutation in AKT2 . Methods Four children (aged 4 months to 11 years) with hypoglycaemia in the absence of elevated serum insulin and ketones and wild-type AKT2 sequence underwent whole-exome sequencing with their parents. Variants were verified with Sanger sequencing and restriction fragment length polymorphism assays. Serum starved primary dermal fibroblasts were used for immunoblotting against phosphorylated AKT to look for basal hyperactivation of the PI3K–AKT pathway. Findings Tissue and lymphocyte DNA from one patient with hypoglycaemia, macrocephaly, and fibrous liver disease revealed a mosaic mutation (p.Glu726Lys) in PIK3CA , encoding the p110α catalytic subunit of phosphoinositide-3-kinase. Dermal fibroblasts showed a small but significant (pAKT Thr308 p PIK3CA mutations in other forms of overgrowth. Another child, who presented with infantile hypoglycaemia and jejunal atresia, had mutations in two constituents of mTORC2 ( mTOR and MLST8 ), which lies upstream from AKT2 in the insulin signalling pathway. Since one variant was inherited from each unaffected parent, these constituents are being evaluated functionally as a possible di-genic explanation for neonatal hypoglycaemia. Interpretation Collectively these studies suggest the existence of a genetically heterogenous group of disorders that are metabolic phenocopies of AKT2-driven fasting hypoglycaemia. Further investigation of this group of naturally occurring human experiments of nature promises to yield novel information about the in-vivo regulation of fasting glucose metabolism and its perturbation in common disease. Funding Rosetrees Trust, Wellcome Trust.

Exercise-induced hyperinsulinism (EIHI) is a hypoglycaemic disorder characterised by inappropriate insulin secretion following anaerobic exercise or pyruvate load. Activating promoter mutations in the MCT1 gene (also known as SCLA16A1), coding for monocarboxylate transporter 1 (MCT1), were shown to associate with EIHI. Recently, transgenic Mct1 expression in pancreatic beta cells was shown to introduce EIHI symptoms in mice. To date, MCT1 has not been demonstrated in insulin-producing cells from an EIHI patient.In vivo insulin secretion was studied during an exercise test before and after the resection of an insulinoma. The presence of MCT1 was analysed using immunohistochemistry followed by laser scanning microscopy, western blot analysis and real-time RT-PCR of MCT1. The presence of MCT1 protein was analysed in four additional insulinoma patients.Clinical testing revealed massive insulin secretion induced by anaerobic exercise preoperatively, but not postoperatively. MCT1 protein was not detected in the patient's normal islets. In contrast, immunoreactivity was clearly observed in the insulinoma tissue. Western blot analysis and real-time RT-PCR showed a four- to fivefold increase in MCT1 in the insulinoma tissue of the EIHI patient compared with human pancreatic islets. MCT1 protein was detected in three of four additional insulinomas.We show for the first time that an MCT1-expressing insulinoma was associated with EIHI and that MCT1 might be present in most insulinomas. Our data suggest that MCT1 expression in human insulin-producing cells can lead to EIHI and warrant further studies on the role of MCT1 in human insulinoma patients.

NMDA receptor dependent anti-diabetic effects Jan Marquard, Silke Otter, Alena Welters, Diran Herebian, Fatih Demir, Annett Schroeter, Olaf Kletke, Martin Kragl, Daniel Eberhard, Barbara Bartosinska, Masa Skelin Klemen, Andraz Stozer, Martin Kohler, Alin Stirban, Freimut Schliess, Tim Heise, Stephan Wnendt, Marjan Slak Rupnik, Per-Olof Berggren, Nikolaj Klocker, Thomas Meissner, Ertan Mayatepek, Eckhard Lammert