Association of Fetal Catecholamines With Neonatal Hypoglycemia.

Importance: Perinatal stress and fetal growth restriction increase the risk of neonatal hypoglycemia. The underlying pathomechanism is poorly understood. In a sheep model, elevated catecholamine concentrations were found to suppress intrauterine insulin secretion, followed by hyperresponsive insulin secretion once the adrenergic stimulus subsided. Objective: To determine whether neonates with risk factors for hypoglycemia have higher catecholamine concentrations in umbilical cord blood (UCB) and/or amniotic fluid (AF) and whether catecholamines are correlated with postnatal glycemia. Design, Setting, and Participants: In a prospective cohort study of 328 neonates at a tertiary perinatal center from September 2020 through May 2022 in which AF and UCB were collected immediately during and after delivery, catecholamines and metanephrines were analyzed using liquid chromatography with tandem mass spectrometry. Participants received postnatal blood glucose (BG) screenings. Exposure: Risk factor for neonatal hypoglycemia. Main Outcomes and Measures: Comparison of catecholamine and metanephrine concentrations between at-risk neonates and control participants, and correlation of concentrations of catecholamines and metanephrines with the number and severity of postnatal hypoglycemic episodes. Results: In this study of 328 neonates (234 in the risk group: median [IQR] gestational age, 270 [261-277] days; and 94 in the control group: median [IQR] gestational age, 273 [270-278] days), growth-restricted neonates showed increased UCB median (IQR) concentrations of norepinephrine (21.10 [9.15-42.33] vs 10.88 [5.78-18.03] nmol/L; P < .001), metanephrine (0.37 [0.13-1.36] vs 0.12 [0.08-0.28] nmol/L; P < .001), and 3-methoxytyramine (0.149 [0.098-0.208] vs 0.091 [0.063-0.149] nmol/L; P = .001). Neonates with perinatal stress had increased UCB median (IQR) concentrations of norepinephrine (22.55 [8.99-131.66] vs 10.88 [5.78-18.03] nmol/L; P = .001), normetanephrine (1.75 [1.16-4.93] vs 1.25 [0.86-2.56] nmol/L; P = .004), and 3-methoxytyramine (0.120 [0.085-0.228] vs 0.091 [0.063-0.149] nmol/L; P = .008) (P < .0083 was considered statistically significant). Concentrations of UCB norepinephrine, metanephrine, and 3-methoxytyramine were negatively correlated with AF C-peptide concentration (rs = -0.212, P = .005; rs = -0.182, P = .016; and rs = -0.183, P = .016, respectively [P < .017 was considered statistically significant]). Concentrations of UCB norepinephrine, metanephrine, and 3-methoxytyramine were positively correlated with the number of hypoglycemic episodes (BG concentration of 30-45 mg/dL) (rs = 0.146, P = .01; rs = 0.151, P = .009; and rs = 0.180, P = .002, respectively). Concentrations of UCB metanephrine and 3-methoxytyramine were negatively correlated with the lowest measured BG concentration (rs = -0.149, P = .01; and rs = -0.153, P = .008, respectively). Conclusions and Relevance: Neonates at risk for hypoglycemia displayed increased catecholamine and metanephrine concentrations that were correlated with postnatal hypoglycemic episodes and lower BG levels; these results are consistent with findings in a sheep model that fetal catecholamines are associated with neonatal ß-cell physiology and that perinatal stress or growth restriction is associated with subsequent neonatal hyperinsulinemic hypoglycemia. Improving the pathomechanistic understanding of neonatal hypoglycemia may help to guide management of newborns at risk for hypoglycemia.

Transitional Neonatal Hypoglycemia and Adverse Neurodevelopment in Midchildhood.

Importance: The circumstances under which neonatal hypoglycemia leads to brain damage remain unclear due to a lack of long-term data on the neurodevelopment of affected children. As a result, diagnostic strategies and treatment recommendations are inconsistent. Objective: To evaluate whether the occurrence of severe transitional neonatal hypoglycemia (defined as having at least 1 blood glucose measurement of 30 mg/dL or below) is associated with adverse neurodevelopment in midchildhood. Design, Setting, and Participants: This cohort study using neurodevelopmental testing of a retrospectively recruited cohort was conducted at a single-center tertiary hospital in Germany between March 2022 and February 2023. Children with neonatal blood glucose screening data were randomly selected from all births between 2010 and 2015. Frequency matching for sex, birth weight, gestational age, socioeconomic status, and primary risk factors for neonatal hypoglycemia was performed. Children with persistent hypoglycemia diseases or any risk factor for adverse neurodevelopment except hypoglycemia were excluded. Data were analyzed between February 2023 and March 2023. Exposure: At least 1 neonatal hypoglycemia measurement with blood glucose measuring 30 mg/dL or below vs all measured blood glucose levels above 30 mg/dL during postnatal blood glucose screening starting on the first day of life. Main Outcomes and Measures: Cognitive function measured by full-scale IQ test. Secondary outcomes included standardized scales of motor, visual, and executive functions, and child behavior, each measured at ages 7 to 11 years. Results: A total of 140 children (mean [SD] age 9.1 [1.3] years; 77 male [55.0%]) participated in the study. Children with severe neonatal hypoglycemia had a 4.8 points lower mean full-scale IQ than controls (107.0 [95% CI, 104.0-109.9] vs 111.8 [95% CI, 108.8-114.8]). They showed a 4.9-fold (95% CI, 1.5-15.5) increased odds of abnormal fine motor function and a 5.3-fold (95% CI, 2.1-13.3) increased odds of abnormal visual-motor integration. Significantly higher T scores for attention problems (58.2 [95% CI, 56.1-60.2] vs 54.6 [95% CI, 52.6-56.6]) and attention-deficit/hyperactivity disorder symptoms (58.2 [95% CI, 56.2-60.2] vs 54.7 [95% CI, 52.8-56.7]) were reported by parents. Conclusions and Relevance: Neonatal hypoglycemia with blood glucose levels of 30 mg/dL or below was associated with an increased risk for suboptimal neurodevelopmental outcomes in midchildhood. These findings imply that treatment strategies should aim to prevent episodes of hypoglycemia at these severely low levels.

Congenital Hyperinsulinism in Humans and Insulin Secretory Dysfunction in Mice Caused by Biallelic DNAJC3 Variants.

The BiP co-chaperone DNAJC3 protects cells during ER stress. In mice, the deficiency of DNAJC3 leads to beta-cell apoptosis and the gradual onset of hyperglycemia. In humans, biallelic DNAJC3 variants cause a multisystem disease, including early-onset diabetes mellitus. Recently, hyperinsulinemic hypoglycemia (HH) has been recognized as part of this syndrome. This report presents a case study of an individual with HH caused by DNAJC3 variants and provides an overview of the metabolic phenotype of individuals with HH and DNAJC3 variants. The study demonstrates that HH may be a primary symptom of DNAJC3 deficiency and can persist until adolescence. Additionally, glycemia and insulin release were analyzed in young DNACJ3 knockout (K.O.) mice, which are equivalent to human infants. In the youngest experimentally accessible age group of 4-week-old mice, the in vivo glycemic phenotype was already dominated by a reduced total insulin secretion capacity. However, on a cellular level, the degree of insulin release of DNAJC3 K.O. islets was higher during periods of increased synthetic activity (high-glucose stimulation). We propose that calcium leakage from the ER into the cytosol, due to disrupted DNAJC3-controlled gating of the Sec61 channel, is the most likely mechanism for HH. This is the first genetic mechanism explaining HH solely by the disruption of intracellular calcium homeostasis. Clinicians should screen for HH in DNAJC3 deficiency and consider DNAJC3 variants in the differential diagnosis of congenital hyperinsulinism.

An expanded clinical spectrum of hypoinsulinaemic hypoketotic hypoglycaemia.

BACKGROUND: Hypoketotic hypoglycaemia with suppressed plasma fatty acids and detectable insulin suggests congenital hyperinsulinism (CHI). Severe hypoketotic hypoglycaemia mimicking hyperinsulinism but without detectable insulin has recently been described in syndromic individuals with mosaic genetic activation of post-receptor insulin signalling. We set out to expand understanding of this entity focusing on metabolic phenotypes. METHODS: Metabolic profiling, candidate gene and exome sequencing were performed in six infants with hypoketotic, hypoinsulinaemic hypoglycaemia, with or without syndromic features. Additional signalling studies were carried out in dermal fibroblasts from two individuals. RESULTS: Two infants had no syndromic features. One was mistakenly diagnosed with CHI. One had mild features of megalencephaly-capillary malformation-polymicrogyria (MCAP) syndrome, one had non-specific macrosomia, and two had complex syndromes. All required intensive treatment to maintain euglycaemia, with CHI-directed therapies being ineffective. Pathogenic PIK3CA variants were found in two individuals - de novo germline c.323G>A (p.Arg108His) in one non-syndromic infant and postzygotic mosaic c.2740G>A (p.Gly914Arg) in the infant with MCAP. No causal variants were proven in the other individuals despite extensive investigation, although rare variants in mTORC components were identified in one. No increased PI3K signalling in fibroblasts of two individuals was seen. CONCLUSIONS: We expand the spectrum of PI3K-related hypoinsulinaemic hypoketotic hypoglycaemia. We demonstrate that pathogenic germline variants activating post-insulin-receptor signalling may cause non-syndromic hypoinsulinaemic hypoketotic hypoglycaemia closely resembling CHI. This distinct biochemical footprint should be sought and differentiated from CHI in infantile hypoglycaemia. To facilitate adoption of this differential diagnosis, we propose the term "pseudohyperinsulinism".

Neonatal hypoglycemia: lack of evidence for a safe management.

Neonatal hypoglycemia affects up to 15% of all newborns. Despite the high prevalence there is no uniform definition of neonatal hypoglycemia, and existing guidelines differ significantly in terms of when and whom to screen for hypoglycemia, and where to set interventional thresholds and treatment goals. In this review, we discuss the difficulties to define hypoglycemia in neonates. Existing knowledge on different strategies to approach this problem will be reviewed with a focus on long-term neurodevelopmental outcome studies and results of interventional trials. Furthermore, we compare existing guidelines on the screening and management of neonatal hypoglycemia. We summarize that evidence-based knowledge about whom to screen, how to screen, and how to manage neonatal hypoglycemia is limited - particularly regarding operational thresholds (single values at which to intervene) and treatment goals (what blood glucose to aim for) to reliably prevent neurodevelopmental sequelae. These research gaps need to be addressed in future studies, systematically comparing different management strategies to progressively optimize the balance between prevention of neurodevelopmental sequelae and the burden of diagnostic or therapeutic procedures. Unfortunately, such studies are exceptionally challenging because they require large numbers of participants to be followed for years, as mild but relevant neurological consequences may not become apparent until mid-childhood or even later. Until there is clear, reproducible evidence on what blood glucose levels may be tolerated without negative impact, the operational threshold needs to include some safety margin to prevent potential long-term neurocognitive impairment from outweighing the short-term burden of hypoglycemia prevention during neonatal period.

Delayed-Onset Transient Hyperinsulinism in Infants with Very Low and Extremely Low Birth Weights: A Cohort Study.

We describe 16 infants born preterm with birth weights <1500 g and transient hyperinsulinism. The onset of hyperinsulinism was delayed and often coincident with clinical stabilization. We hypothesize that postnatal stress caused by prematurity and associated problems may contribute to development of delayed-onset transient hyperinsulinism.

Frequency and characteristics of diabetes in lipodystrophies and insulin receptoropathies compared with type 1 and type 2: results from the multicenter DPV registry.

Objective: To investigate the frequency, treatment, and outcome of patients with diabetes due to severe insulin resistance syndromes (SIRS). Research Design and Methods: Based on data from the multicenter prospective Diabetes Registry DPV, we analyzed diagnosis, treatment, and outcome of 636,777 patients with diabetes from 1995 to 2022. Results: Diabetes due to SIRS was documented in 67 cases (62.7% females), 25 (37%) had lipodystrophies (LD) and 42 (63%) had congenital defects of insulin signaling. The relative frequency compared to type 1 diabetes (T1D) was about 1:2300. Median age at diabetes diagnosis in patients with SIRS was 14.8 years (interquartile range (IQR) 12.8-33.8). A total of 38 patients with SIRS (57%) received insulin and 34 (51%) other antidiabetics, mostly metformin. As high as 16% of patients with LD were treated with fibrates. Three out of eight patients with generalized LD (37.5%) were treated with metreleptin and one patient with Rabson-Mendenhall syndrome was treated with recombinant insulin-like growth factor 1. The median glycated hemoglobin level at follow-up was 7.1% (54 mmol/mol). Patients with LD had higher triglycerides than patients with T1D and T2D (P < 0.001 and P = 0.022, respectively), and also significantly higher liver enzymes and lower high-density lipoprotein cholesterol than patients with T1D (P < 0.001). Patients with insulin receptor disorders were significantly less likely to be treated with antihypertensive medication than patients with T2D (P = 0.042), despite having similar levels of hypertension. Conclusions: Diabetes due to SIRS is rarely diagnosed and should be suspected in lean children or young adults without classical T1D. Awareness of cardiovascular risk factors in these patients should be raised.

Protecting against brain damage by improving treatment in neonates with hypoglycaemia: ProBrain-D-a study protocol of a prospective longitudinal study.

INTRODUCTION: Although neonatal hypoglycaemia is the most common metabolic problem in neonates, there is no standard guideline for screening. Additionally, treatment of neonatal hypoglycaemia and glucose administration thresholds are discussed controversially. Severe hypoglycaemia can lead to brain damage, but data on the effects of mild hypoglycaemia on neurological development are limited. To our knowledge, this is the first prospective longitudinal cohort study to analyse if the implementation of a new diagnosis and treatment standard for neonatal hypoglycaemia may improve the outcome of neonates at risk for hypoglycaemia, especially concerning neurodevelopment. Furthermore, the acceptance and feasibility of the standard among different professional groups and parents are analysed. METHODS AND ANALYSIS: After implementation of a structured standard operating procedure (SOP), detailing preventive measures, blood glucose screening and neonatal hypoglycaemia treatment in a tertiary care hospital, 678 neonates ≥35+0 weeks of gestation will be recruited in a monocentric prospective cohort study. For comparison, 139 children born before the implementation of this new SOP, who had risk factors for neonatal hypoglycaemia or qualified for blood glucose measurements are recruited (retrospective cohort). For the primary end point, comparative analyses between and within the prospective and retrospective cohorts will be performed regarding the neurological outcome at 2-2.5 years of age in Bayley Scales of Infant Development. Furthermore, comprehensive clinical data and data on nutrition and developmental milestones are assessed at different time points (6 weeks, 6, 12, 18 and 24 months) in the prospective cohort. Acceptance and feasibility of the new standard are assessed using questionnaires. ETHICS AND DISSEMINATION: The study has been approved by the Ethics Committee of the Medical Faculty of the Heinrich-Heine-University Düsseldorf (20201162). The results of this study will be disseminated through peer-reviewed journals and presented at international conferences. TRIAL REGISTRATION NUMBER: DRKS00024086.

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

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

Clinical presentation and long-term outcome of patients with KCNJ11/ABCC8 variants: Neonatal diabetes or MODY in the DPV registry from Germany and Austria.

OBJECTIVE: To describe clinical presentation/longterm outcomes of patients with ABCC8/KCNJ11 variants in a large cohort of patients with diabetes. RESEARCH DESIGN AND METHODS: We analyzed patients in the Diabetes Prospective Follow-up (DPV) registry with diabetes and pathogenic variants in the ABCC8/KCNJ11 genes. For patients with available data at three specific time-points-classification as K+ -channel variant, 2-year follow-up and most recent visit-the longitudinal course was evaluated in addition to the cross-sectional examination. RESULTS: We identified 93 cases with ABCC8 (n = 54)/KCNJ11 (n = 39) variants, 63 of them with neonatal diabetes. For 22 patients, follow-up data were available. Of these, 19 were treated with insulin at diagnosis, and the majority of patients was switched to sulfonylurea thereafter. However, insulin was still administered in six patients at the most recent visit. Patients were in good metabolic control with a median (IQR) A1c level of 6.0% (5.5-6.7), that is, 42.1 (36.6-49.7) mmol/mol after 2 years and 6.7% (6.0-8.0), that is, 49.7 (42.1-63.9) mmol/mol at the most recent visit. Five patients were temporarily without medication for a median (IQR) time of 4.0 (3.5-4.4) years, while two other patients continue to be off medication at the last follow-up. CONCLUSIONS: ABCC8/KCNJ11 variants should be suspected in children diagnosed with diabetes below the age of 6 months, as a high percentage can be switched from insulin to oral antidiabetic drugs. Thirty patients with diabetes due to pathogenic variants of ABCC8 or KCNJ11 were diagnosed beyond the neonatal period. Patients maintain good metabolic control even after a diabetes duration of up to 11 years.

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.

Reliability and Observer Dependence of Signs of Neonatal Hypoglycemia.

OBJECTIVES: To evaluate, using video documentation, the sensitivity, specificity, and interobserver reliability of visualizable signs of neonatal hypoglycemia at different glucose concentrations in neonates. STUDY DESIGN: In a prospective cohort study of 145 neonates with and without risk factors for hypoglycemia, 430 videos were recorded before blood glucose measurements and analyzed by 10 blinded investigators of different professions. The primary outcome measures were sensitivity and specificity for clinical detection of hypoglycemia. RESULTS: The overall sensitivity to detect low blood glucose (<55 mg/dL [<3.1 mmol/L]) based on signs was 30%, and the specificity was 82%. Significantly more investigators suspected hypoglycemia while viewing videos of infants with blood glucose levels of 46-54 mg/dL (2.6-3.0 mmol/L) and 30-45 mg/dL (1.7-2.5 mmol/L) compared with ≥55 mg/dL (≥3.1 mmol/L) (29 ± 3% and 31 ± 4% vs 18 ± 1%; P = .001; P = .007). After 48 hours of life, significantly more investigators suspected hypoglycemia in videos of infants with blood glucose levels of ≤45 mg/dL (≤2.5 mmol/L) compared with blood glucose levels of >45 mg/dL (>2.5 mmol/L) (28.9 ± 8.1% vs 10.9 ± 1.8%; P = .007). For blood glucose levels 30-45 mg/dL (1.7-2.5 mmol/L), sensitivity varied widely between investigators, ranging from 5% to 62%. Three hypoglycemic episodes <30 mg/dL (<1.7 mmol/L) were only partially recognized. CONCLUSIONS: Clinical observation of signs is neither sensitive nor specific to detect neonatal hypoglycemia, and there are large interobserver differences. Thus, guidelines on neonatal hypoglycemia should reconsider whether distinguishing between asymptomatic and symptomatic hypoglycemia provides useful information for the management of neonatal hypoglycemia, because it may pose a risk for systematic under-recognition and undertreatment, leading to an increased risk for neurodevelopmental impairment. TRIAL REGISTRATION: German Clinical Trials Register: DRKS00021500 www.drks.de/drks_web/setLocale_EN.do.

Interleukin-7 and soluble Interleukin-7 receptor levels in type 1 diabetes - Impact of IL7RA polymorphisms, HLA risk genotypes and clinical features.

High soluble IL-7 receptor (sIL-7R) serum levels and associated single nucleotide polymorphisms in the IL7RA gene were found in autoimmune diseases including type 1 diabetes. Further determinants on sIL-7R and IL-7 availability as well as changes during type 1 diabetes disease course remain elusive. Here we performed multiparameter analysis to identify influential genetic and disease-associated factors on sIL-7R and IL-7 serum levels during type 1 diabetes disease course (239 children) and in healthy controls (101 children). We found higher sIL-7R serum concentrations at type 1 diabetes onset and decreasing levels during therapy whereas IL-7 was only higher in long term patients as compared to controls. Multiple linear regression analyses revealed several factors, including IL7RA SNP rs6897932 and HLA risk haplotypes, influencing sIL-7R levels but not IL-7, which was solely associated with the sIL-7R. This study revealed unexpected complexity in the regulation of the sIL-7R but not for IL-7.

Next Generation Sequencing Identifies the HLA-DQA1*03:03 Allele in the Type 1 Diabetes Risk-Associated HLA-DQ8 Serotype.

The highest genetic type 1 diabetes risk is conferred by HLA class II haplotypes defined by alleles at the HLA-DR and -DQ loci. The combination of HLA-DQA1*03:01 and DQB1*03:02 alleles (summarized as 'HLA-DQ8') is reported to be among the two most prevalent HLA class II haplotypes in Caucasian type 1 diabetes patients. This classification is based on conventional genotyping of exon 2 of the DQ gene locus and excludes exon 3. In this study, HLA genotyping on the type 1 diabetes susceptibility loci HLA-DRB1, DQA1 and DQB1 was performed using a high-resolution next generation sequencing method. In addition to the routinely examined exon 2, exon 3 was also sequenced. Samples from 229 children with type 1 diabetes were included and compared to a cohort of 9,786 controls. In addition to previously described HLA-DQ haplotypes in type 1 diabetes patients, we found that as well as HLA-DQA1*03:01,HLA-DQA1*03:03 also contributed to HLA-DQ8. HLA-DQA1*03:03 differs from HLA-DQA1*03:01 by one nucleotide substitution in exon 3 at position 160, leading to a single amino acid replacement. DRB1*04:05 was exclusively associated with DQA1*03:03 whereas the DRB1*04:01 haplotype comprised either DQA1*03:01 or DQA1*03:03. Significantly increased type 1 diabetes risk was confirmed for all these haplotypes with only minor differences between DQA1*03:01 and DQA1*03:03 alleles. This study identified the HLA-DQA1*03:03 allele as an addition to the already known type 1 diabetes risk haplotypes, and can contribute to more precise HLA genotyping approaches.

Interleukin-7-dependent nonclassical monocytes and CD40 expression are affected in children with type 1 diabetes.

The important role of IL-7 in the generation of self-reactive T-cells in autoimmune diseases is well established. Recent studies on autoimmunity-associated genetic polymorphisms indicated that differential IL-7 receptor (IL-7R) expression of monocytes may play a role in the underlying pathogenesis. The relevance of IL-7-mediated monocyte functions in type 1 diabetes remains elusive. In the present study, we characterized monocyte phenotype and IL-7-mediated effects in children with type 1 diabetes and healthy controls with multicolor flow cytometry and t-distributed Stochastic Neighbor-Embedded (t-SNE)-analyses. IL-7R expression of monocytes rapidly increased in vitro and was boosted through LPS. In the presence of IL-7, we detected lower monocyte IL-7R expression in type 1 diabetes patients as compared to healthy controls. This difference was most evident for the subset of nonclassical monocytes, which increased after IL-7 stimulation. t-SNE analyses revealed IL-7-dependent differences in monocyte subset distribution and expression of activation and maturation markers (i.e., HLA-DR, CD80, CD86, CD40). Notably, monocyte CD40 expression increased considerably by IL-7 and CD40/IL-7R co-expression differed between patients and controls. This study shows the unique effects of IL-7 on monocyte phenotype and functions. Lower IL-7R expression on IL-7-induced CD40high monocytes and impaired IL-7 response characterize monocytes from patients with type 1 diabetes.

Long-term trends of BMI and cardiometabolic risk factors among adults with type 1 diabetes: An observational study from the German/Austrian DPV registry.

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.

CD5-expressing CD8+ T-cell subsets differ between children with type 1 diabetes and controls.

Different lymphocyte subsets are involved in autoimmune pathogenesis of type 1 diabetes (T1D). Previous studies suggested a role of CD5-expressing T and B cells including rare unconventional lymphocytes with combined T- and B-cell features [dual expressing (DE) cells]. We performed algorithm-supported multiparameter flow cytometry and quantitative PCR to investigate immune cell subsets and DE cells in children with T1D (n = 20) and matched controls (n = 20). Comparisons of conventional immune cells detected increased proportions of CD3+ T cells in T1D patients, whereas CD19+ B-cell proportions were comparable to controls. Self-organizing maps for flow cytometry analyses (FlowSOM) showed highly similar CD5-expressing B-cell subsets and no differences for DE cells were detected between the study groups by flow cytometry or specific quantitative PCR. Notably, differences in CD8+ T cells were indicated by FlowSOM and similarity-based t-distributed stochastic neighbor embedding (tSNE) analyses. Study group comparisons confirmed significantly reduced CD8+ T-cell proportions with moderate or low CD5 expression in T1D patients. Finally, in vitro experiments showed stable CD5 expression differences of CD8+ T cells after T-cell activation, cytokine stimulation and culture. We observed differences of T-cell coreceptor CD5 expression in T1D patients with potential relevance for immune regulation of CD8+ T-cell activation.

Challenges in management of transient hyperinsulinism - a retrospective analysis of 36 severely affected children.

OBJECTIVES: Transient hyperinsulinism (THI) is a hypoglycemia disorder which resolves spontaneously within the first weeks or months of life. The pathomechanism of THI is not elucidated yet; however, it is known that perinatal stress predisposes for THI. We aimed to characterize the clinical phenotype and treatment of children with THI, and to identify options for improved management. METHODS: A retrospective analysis of 36 children with THI treated at the University Children's Hospital Düsseldorf between 2007 and 2019 was performed. RESULTS: All children had risk factors for neonatal hypoglycemia or indicators of perinatal stress. Eighty three percent were diagnosed with hypoglycemia on day of life (DOL)1. None of the six diagnosed later had routine blood glucose screening and showed significantly lower blood glucose levels at the time of first blood glucose measurement compared to the children diagnosed on DOL1. Ninety seven percent of all children received intravenous glucose, 42% received continuous glucagon and 81% were started on diazoxide. Diazoxide withdrawal and subsequent fasting tests lacked standardization and were based on clinical experience. Three patients had a subsequent episode of hypoglycemia, after fasting studies only demonstrated "clinical" remission without proving the ability to ketogenesis. CONCLUSIONS: Any kind of perinatal stress might pose a risk to develop THI, and postnatal monitoring for hypoglycemia still needs to be improved. Diazoxide is effective in children with THI; however, further studies are needed to guide the development of criteria and procedures for the initiation and discontinuation of treatment. Furthermore, establishing consensus diagnostic criteria/definitions for THI would improve comparability between studies.

Clinical management and knowledge of neonatal hypoglycaemia in Germany: A national survey of midwives and nurses.

AIM: Despite being a common metabolic condition, the detection and care of neonatal hypoglycaemia in Germany largely depends on the infant's health-care provider, rather than a national protocol. Therefore, this study aimed to evaluate midwives' and nurses' knowledge and management of neonatal hypoglycaemia and to determine the need for national guidelines. METHODS: An anonymous online survey was developed and completed by 127 perinatal nurses and midwives. Descriptive statistics, Mann-Whitney-U, χ2 and Fisher's exact tests were used to summarise and analyse the results. RESULTS: In total, 82% of respondents indicated using guidelines but routine blood glucose screening for neonates at risk for hypoglycaemia was rarely reported (44%). A blood glucose concentration of 2.5 mmol/L (45 mg/dL) was considered the treatment threshold by 52% of the respondents. However, the responses to clinical scenarios showed distinct differences regarding the management of neonatal hypoglycaemia. Finally, 49% of respondents reported insufficient knowledge regarding neonatal hypoglycaemia and 77% indicated that they would advocate the implication of enhanced national guidelines. CONCLUSIONS: There is considerable variation in knowledge about the prevention, screening and management of neonatal hypoglycaemia among nurses and midwives in Germany. Enhanced guidelines and education of health-care professionals are urgently needed to provide the best possible care to all hypoglycaemic newborns.

Diazoxide-responsive hyperinsulinaemic hypoglycaemia in tyrosinaemia type 1.

SUMMARY: Tyrosinaemia type 1 (TT1) is a rare inherited disorder of amino acid metabolism typically presenting with liver failure and renal tubular dysfunction. We describe three individuals with TT1 and transient hyperinsulinaemic hypoglycaemia (HH). Two siblings with TT1 and acute liver dysfunction were diagnosed with hyperinsulinaemic hypoglycaemia in the neonatal period. Both siblings were successfully treated with diazoxide/chlorthiazide and treatment was gradually weaned and stopped after 8 and 6 months of age respectively. The third patient presented with a neonatal liver failure with mild cholestasis, coagulopathy, fundus haemorrhages, vitamin A and E deficiency and hyperinsulinaemic hypoglycaemia. He maintained euglycaemia on high dose diazoxide (5-12 mg/kg/day) but developed pulmonary hypertension at 12 weeks of age. After discontinuation of diazoxide, he continued maintaining his blood glucose (BG) within the normal range. Although histological abnormalities of the pancreas including beta-cell hyperplasia are well documented, the exact mechanism of excessive insulin secretion in TT1 is not well understood. It may be related to the accumulation of toxic metabolites in the target organs including pancreas. Therefore, in patients with TT1 and persistent hypoglycaemia beyond the recovery of the acute liver failure, it is important to exclude hyperinsulinism which is usually transient and can be successfully treated with diazoxide and chlorothiazide. Further studies are required to determine which factors contribute to excessive insulin secretion in patients with TT1. LEARNING POINTS: Every child with TT1 should be monitored for signs and symptoms of hypoglycaemia and screened for HH at the time of real hypoglycaemia. If hypoglycaemic episodes persist even after improvement of liver function, hyperinsulinism should be suspected. Treatment with diazoxide is effective, however, children need to be monitored closely for possible side effects. The pathophysiological mechanism of hyperinsulinism in children with TT1 is not elucidated yet and further studies are required to determine which factors contribute to excessive insulin secretion in patients with TT1.