Incidence and risk factors of cerebral sinovenous thrombosis in infants.

AIM: To describe the incidence of term and preterm neonatal cerebral sinovenous thrombosis (CSVT) and identify perinatal risk factors. METHOD: This was a national capture-recapture calculation-corrected surveillance and nested case-control study. Infants born preterm and at term with magnetic resonance imaging-confirmed neonatal CSVT were identified by surveillance in all paediatric hospitals in Germany (2015-2017). Incidence was corrected for underreporting using a capture-recapture method in one federal state and then extrapolated nationwide. We reviewed PubMed for comparisons with previously reported incidence estimators. We used a population-based perinatal database for quality assurance to select four controls per case and applied univariate and multivariable regression for risk factor analysis. RESULTS: Fifty-one newborn infants (34 males, 17 females; 14 born preterm) with neonatal CSVT were reported in the 3-year period. The incidence of term and preterm neonatal CSVT was 6.6 (95% confidence interval [CI] 4.4-8.7) per 100 000 live births. Median age at time of confirmation of the diagnosis was 9.95 days (range 0-39d). In the univariate analysis, male sex, preterm birth, hypoxia and related indicators (umbilical artery pH <7.1; 5-minute Apgar score <7; intubation/mask ventilation; perinatal asphyxia), operative vaginal delivery, emergency Caesarean section, and pathological fetal Doppler sonography were associated (p<0.05) with neonatal CSVT. Multivariable regression yielded hypoxia (odds ratio=20.3; 95% CI 8.1-50.8) as the independent risk factor. INTERPRETATION: Incidence of neonatal CSVT was within the range of other population-based studies. The results suggest that hypoxia is an important perinatal risk factor for the aetiology of neonatal CSVT.

Risk factors for perinatal arterial ischaemic stroke: a large case-control study.

AIM: To identify maternal, obstetric, and neonatal risk factors related to perinatal arterial ischaemic stroke (PAIS) diagnosed within 28 days after birth and to understand the underlying pathophysiology. METHOD: For case and control ascertainment, we used active surveillance in 345 paediatric hospitals and a population-based perinatal database for quality assurance of hospital care. We analysed complete cases of PAIS using logistic regression. Multivariate analysis was guided by a directed acyclic graph. RESULTS: After exclusion of records with missing data, we analysed 134 individuals with PAIS and 576 comparison individuals. In univariate analysis, male sex, preterm birth (<37wks gestational age), small for gestational age (SGA), low umbilical artery pH (<7.1), low 5-minute-Apgar score (<7), multiple pregnancies, hypoxia, intubation/mask ventilation, nulliparity, Caesarean section, vaginal-operative delivery, chorioamnionitis, and oligohydramnios were associated with an increased risk. Mutual adjustment yielded male sex (odds ratio [OR] 1.81; 95% confidence interval [CI] 1.20-2.73), multiple birth (OR 3.22; 95% CI 1.21-8.58), chorioamnionitis (OR 9.89; 95% CI 2.88-33.94), preterm birth (OR 1.86; 95% CI 1.01-3.43), and SGA (OR 3.05; 95% CI 1.76-5.28) as independent risk factors. INTERPRETATION: We confirmed the increased risk in males and the role of chorioamnionitis and SGA for PAIS, pointing to the importance of inflammatory processes and fetal-placental insufficiency. Multiple birth and preterm birth were additional risk factors. WHAT THIS PAPER ADDS: Chorioamnionitis and small for gestational age (SGA) precede perinatal arterial ischaemic stroke (PAIS). Chorioamnionitis and SGA are independent risk factors for PAIS. Inflammatory processes and fetal-placental insufficiency are the likely underlying mechanisms. Multiple birth and preterm birth are additional risk factors.

Progression from islet autoimmunity to clinical type 1 diabetes is influenced by genetic factors: results from the prospective TEDDY study.

BACKGROUND: Progression time from islet autoimmunity to clinical type 1 diabetes is highly variable and the extent that genetic factors contribute is unknown. METHODS: In 341 islet autoantibody-positive children with the human leucocyte antigen (HLA) DR3/DR4-DQ8 or the HLA DR4-DQ8/DR4-DQ8 genotype from the prospective TEDDY (The Environmental Determinants of Diabetes in the Young) study, we investigated whether a genetic risk score that had previously been shown to predict islet autoimmunity is also associated with disease progression. RESULTS: Islet autoantibody-positive children with a genetic risk score in the lowest quartile had a slower progression from single to multiple autoantibodies (p=0.018), from single autoantibodies to diabetes (p=0.004), and by trend from multiple islet autoantibodies to diabetes (p=0.06). In a Cox proportional hazards analysis, faster progression was associated with an increased genetic risk score independently of HLA genotype (HR for progression from multiple autoantibodies to type 1 diabetes, 1.27, 95% CI 1.02 to 1.58 per unit increase), an earlier age of islet autoantibody development (HR, 0.68, 95% CI 0.58 to 0.81 per year increase in age) and female sex (HR, 1.94, 95% CI 1.28 to 2.93). CONCLUSIONS: Genetic risk scores may be used to identify islet autoantibody-positive children with high-risk HLA genotypes who have a slow rate of progression to subsequent stages of autoimmunity and type 1 diabetes.

Blood draws up to 3% of blood volume in clinical trials are safe in children.

AIM: Recommendations for maximum blood draw in children range from 1 to 5% despite limited evidence. The aim of the study was to assess the safety of blood draws in children aged six months to 12 years targeting volumes of 3% of total blood volume. METHODS: Children who experienced three-monthly blood draws during participation in one of three investigators initiated clinical trials conducted in our institution were examined. In total, 629 venous blood draws were performed in 141 children. Adverse events and blood counts were assessed. RESULTS: Overall, 608 adverse events were reported. None of these included symptoms that reflected concerns on blood draw volumes or frequency. Anaemia and red cell or haemoglobin measurements outside the normal age range were not observed. A reduction in haemoglobin, haematocrit, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration and mean corpuscular volume was noted in children participating in one of the three trials analysed. CONCLUSION: Regular blood draws of up to 3% of total blood volume were not associated with signs of anaemia or hypovolaemia in young children. We suggest that the European recommendations be revised for clinical studies in which children are not exposed to treatments that are associated with anaemia risk.

Associations of maternal type 1 diabetes with childhood adiposity and metabolic health in the offspring: a prospective cohort study.

AIMS/HYPOTHESIS: Exposure to an intrauterine hyperglycaemic environment has been suggested to increase the offspring's later risk for being overweight or having metabolic abnormalities, but conclusive evidence for pregnancies affected by maternal type 1 diabetes is still lacking. This study aims to analyse the relationship between maternal type 1 diabetes and the offspring's metabolic health and investigate whether birthweight and/or changes in the offspring's metabolome are in the potential pathway. METHODS: We analysed data from 610 and 2169 offspring having a first-degree relative with type 1 diabetes from the TEENDIAB and BABYDIAB/BABYDIET cohorts, respectively. Anthropometric and metabolic outcomes, assessed longitudinally at 0.3-18 years of age, were compared between offspring of mothers with type 1 diabetes and offspring of non-diabetic mothers but with fathers or siblings with type 1 diabetes using mixed regression models. Non-targeted metabolomic measurements were carried out in 500 individuals from TEENDIAB and analysed with maternal type 1 diabetes and offspring overweight status. RESULTS: The offspring of mothers with type 1 diabetes had a higher BMI SD score (SDS) and an increased risk for being overweight than the offspring of non-diabetic mothers (e.g. OR for overweight status in TEENDIAB 2.40 [95% CI 1.41, 4.06]). Further, waist circumference SDS, fasting levels of glucose, insulin and C-peptide, and insulin resistance and abdominal obesity were significantly increased in the offspring of mothers with type 1 diabetes, even when adjusted for potential confounders and birthweight. Metabolite patterns related to androgenic steroids and branched-chain amino acids were found to be associated with offspring's overweight status, but no significant associations were observed between maternal type 1 diabetes and metabolite concentrations in the offspring. CONCLUSIONS/INTERPRETATION: Maternal type 1 diabetes is associated with offspring's overweight status and metabolic health in later life, but this is unlikely to be caused by alterations in the offspring's metabolome.

Genetic scores to stratify risk of developing multiple islet autoantibodies and type 1 diabetes: A prospective study in children.

BACKGROUND: Around 0.3% of newborns will develop autoimmunity to pancreatic beta cells in childhood and subsequently develop type 1 diabetes before adulthood. Primary prevention of type 1 diabetes will require early intervention in genetically at-risk infants. The objective of this study was to determine to what extent genetic scores (two previous genetic scores and a merged genetic score) can improve the prediction of type 1 diabetes. METHODS AND FINDINGS: The Environmental Determinants of Diabetes in the Young (TEDDY) study followed genetically at-risk children at 3- to 6-monthly intervals from birth for the development of islet autoantibodies and type 1 diabetes. Infants were enrolled between 1 September 2004 and 28 February 2010 and monitored until 31 May 2016. The risk (positive predictive value) for developing multiple islet autoantibodies (pre-symptomatic type 1 diabetes) and type 1 diabetes was determined in 4,543 children who had no first-degree relatives with type 1 diabetes and either a heterozygous HLA DR3 and DR4-DQ8 risk genotype or a homozygous DR4-DQ8 genotype, and in 3,498 of these children in whom genetic scores were calculated from 41 single nucleotide polymorphisms. In the children with the HLA risk genotypes, risk for developing multiple islet autoantibodies was 5.8% (95% CI 5.0%-6.6%) by age 6 years, and risk for diabetes by age 10 years was 3.7% (95% CI 3.0%-4.4%). Risk for developing multiple islet autoantibodies was 11.0% (95% CI 8.7%-13.3%) in children with a merged genetic score of >14.4 (upper quartile; n = 907) compared to 4.1% (95% CI 3.3%-4.9%, P < 0.001) in children with a genetic score of ≤14.4 (n = 2,591). Risk for developing diabetes by age 10 years was 7.6% (95% CI 5.3%-9.9%) in children with a merged score of >14.4 compared with 2.7% (95% CI 1.9%-3.6%) in children with a score of ≤14.4 (P < 0.001). Of 173 children with multiple islet autoantibodies by age 6 years and 107 children with diabetes by age 10 years, 82 (sensitivity, 47.4%; 95% CI 40.1%-54.8%) and 52 (sensitivity, 48.6%, 95% CI 39.3%-60.0%), respectively, had a score >14.4. Scores were higher in European versus US children (P = 0.003). In children with a merged score of >14.4, risk for multiple islet autoantibodies was similar and consistently >10% in Europe and in the US; risk was greater in males than in females (P = 0.01). Limitations of the study include that the genetic scores were originally developed from case-control studies of clinical diabetes in individuals of mainly European decent. It is, therefore, possible that it may not be suitable to all populations. CONCLUSIONS: A type 1 diabetes genetic score identified infants without family history of type 1 diabetes who had a greater than 10% risk for pre-symptomatic type 1 diabetes, and a nearly 2-fold higher risk than children identified by high-risk HLA genotypes alone. This finding extends the possibilities for enrolling children into type 1 diabetes primary prevention trials.

Fasting hypoglycemia is associated with disease progression in presymptomatic early stage type 1 diabetes.

OBJECTIVE: In children with presymptomatic type 1 diabetes, intermittent hyperglycemia and rising hemoglobin A1c levels are a known signal of progression toward insulin-dependency. Episodes of hypoglycemia, however, have also been reported in one published case. We investigated the prevalence of hypoglycemia and its association with disease progression in children with presymptomatic type 1 diabetes. METHODS: We compared the frequency of hypoglycemic fasting blood glucose levels (<60 mg/dL) in 48 autoantibody negative and 167 multiple ß-cell autoantibody positive children aged 2 to 5 years. We classified the autoantibody positive children into three categories based on their glucose levels in fasting state (hypoglycemic [<60 mg/dL], normoglycemic [60-99 mg/dL] or hyperglycemic [≥100 mg/dL]). We then compared the glucose levels under challenge during oral glucose tolerance tests (OGTTs) between the three categories. RESULTS: In the autoantibody positive children, 5.1% of the fasting samples were hypoglycemic, while in the autoantibody negative children no hypoglycemia was observed. Hypoglycemia occurred more often in autoantibody positive children who had already entered stage 2 or stage 3 of type 1 diabetes than in stage 1 patients (P = 0.02). Children who had hypoglycemic compared to normoglycemic fasting blood glucose values had higher 120-minute blood glucose values under OGTT challenge, and a higher rate of pathological OGTTs (P = 0.04). CONCLUSIONS: Fasting hypoglycemia seems to be an indicator of disease progression in presymptomatic type 1 diabetes and may therefore represent a novel marker for the identification of children who should be monitored more closely for progression toward insulin-dependent type 1 diabetes.

Cesarean Section on the Risk of Celiac Disease in the Offspring: The Teddy Study.

OBJECTIVE: Cesarean section (C-section) is associated with various immune-mediated diseases in the offspring. We investigated the relationship between mode of delivery and celiac disease (CD) and CD autoimmunity (CDA) in a multinational birth cohort. METHODS: From 2004 to 2010, infants from the general population who tested positive for HLA DR3-DQ2 or DR4-DQ8 were enrolled in The Environmental Determinants for Diabetes in the Young (TEDDY) study. Children were annually screened for transglutaminase autoantibodies, if positive, they are retested after 3 to 6 months and those persistently positive defined as CDA. Associations of C-section with maternal (age, education level, parity, pre-pregnancy weight, diabetes, smoking, weight gain during pregnancy) and child characteristics (gestational age, birth weight) were examined by Fisher exact test or Wilcoxon rank-sum test. Hazard ratios (HRs) for CDA or CD were calculated by Cox proportional hazard regression models. RESULTS: Of 6087 analyzed singletons, 1600 (26%) were born by C-section (Germany 38%, United States 37%, Finland 18%, Sweden 16%), and the remaining were born vaginally without instrumental support; 979 (16%) had developed CDA and 343 (6%) developed CD. C-section was associated with lower risk for CDA (hazard ratio [HR] = 0.85; 95% confidence interval [CI] 0.73, 0.99 P = 0.032) and CD (HR = 0.75; 95% CI 0.58, 0.98; P = 0.034). After adjusting for country, sex, HLA-genotype, CD in family, maternal education, and breast-feeding duration, significance was lost for CDA (HR = 0.91; 95% CI 0.78, 1.06; P = 0.20) and CD (HR = 0.85; 95% CI 0.65, 1.11; P = 0.24). Presurgical ruptured membranes had no influence on CDA or CD development. CONCLUSION: C-section is not associated with increased risk for CDA or CD in the offspring.

Type 1 Diabetes Incidence and Risk in Children With a Diagnosis of COVID-19.

This study used a population-based individual patient data set that included diagnoses of COVID-19 to determine whether there was a temporal association between COVID-19 and type 1 diabetes in children.

Peptide serum markers in islet autoantibody-positive children.

AIMS/HYPOTHESIS: We sought to identify minimal sets of serum peptide signatures as markers for islet autoimmunity and predictors of progression rates to clinical type 1 diabetes in a case-control study. METHODS: A double cross-validation approach was applied to first prioritise peptides from a shotgun proteomic approach in 45 islet autoantibody-positive and -negative children from the BABYDIAB/BABYDIET birth cohorts. Targeted proteomics for 82 discriminating peptides were then applied to samples from another 140 children from these cohorts. RESULTS: A total of 41 peptides (26 proteins) enriched for the functional category lipid metabolism were significantly different between islet autoantibody-positive and autoantibody-negative children. Two peptides (from apolipoprotein M and apolipoprotein C-IV) were sufficient to discriminate autoantibody-positive from autoantibody-negative children. Hepatocyte growth factor activator, complement factor H, ceruloplasmin and age predicted progression time to type 1 diabetes with a significant improvement compared with age alone. CONCLUSION/INTERPRETATION: Distinct peptide signatures indicate islet autoimmunity prior to the clinical manifestation of type 1 diabetes and enable refined staging of the presymptomatic disease period.

Infections in Early Life and Development of Celiac Disease.

It has been suggested that early infections are associated with increased risk for later celiac disease (CD). We analyzed prospective claims data of infants from Bavaria, Germany, born between 2005 and 2007 (n = 295,420), containing information on medically attended infectious diseases according to International Classification of Diseases, Tenth Revision, codes in quarterly intervals. We calculated hazard ratios and 95% confidence intervals for time to CD diagnosis by infection exposure, adjusting for sex, calendar month of birth, and number of previous healthcare visits. CD risk was higher among children who had had a gastrointestinal infection during the first year of life (hazard ratio = 1.32, 95% confidence interval: 1.12, 1.55) and, to a lesser extent, among children who had had a respiratory infection during the first year of life (hazard ratio = 1.22, 95% confidence interval: 1.04, 1.43). Repeated gastrointestinal infections during the first year of life were associated with particularly increased risk of CD in later life. These findings indicate that early gastrointestinal infections may be relevant for CD development.

Thymus Growth and Fetal Immune Responses in Diabetic Pregnancies.

Type 1 diabetes (T1D) during pregnancy possibly affects the development of the thymus and the maturation of the immune system in the offspring. The aim of the ImmunDiabRisk study was to investigate thymus growth and maternal and fetal immune responses in pregnancies with and without T1D. The thymus circumferences of the fetuses of pregnant women with T1D (n=49) and without diabetes (n=59) were measured using ultrasound around the 29th gestational week and standardized for gestational age. Simultaneously, the frequencies and total numbers of cell markers were analyzed by flow cytometry in maternal peripheral blood, and at birth in umbilical cord blood. The standardized circumference of the thymus was similar in fetuses of mothers with and without T1D (p=0.26). We observed higher numbers of FOXP3 Tregs, memory Tregs, erythrocytes, and lymphocytes in the cord blood from T1D pregnancies (p=0.01, p=0.002, p=0.002 and p=0.02, respectively). The frequencies of CD4+/CD8+ T cells correlated positively in maternal blood and umbilical cord blood of mother-child pairs, as did the levels of neutrophils (Spearman's correlation coefficient r=0.43, p=0.02 for CD4+/CD8+ cells; r=0.46, p=0.03 for neutrophils), while no significant correlations were observed between thymus circumference and any cell markers in the child. Parts of the prenatal immune system seem to develop differently in the offspring of mothers with and without T1D. The correlation of Tregs between maternal blood and cord blood may indicate a significant cross-talk between the maternal and fetal immune system.

Associations of growth patterns and islet autoimmunity in children with increased risk for type 1 diabetes: a functional analysis approach.

BACKGROUND: Several studies indicate associations between early growth and type 1 diabetes (T1D). However, it remains an open question whether these findings can be translated to typical growth patterns associated with increased risk for T1D-associated islet autoimmunity. METHODS: We analyzed pooled data from 2236 children followed up in two large prospective German birth cohorts with a genetically increased risk for T1D including 18 564 measurements of height and weight, which were transformed to sex- and age-specific standard deviation scores (SDS). A total of 191 children developed any islet autoantibodies, 101 multiple islet autoantibodies. We applied a model-based clustering technique to derive typical height and body mass index (BMI) growth patterns, stratified for maternal T1D status. These patterns were used to predict islet autoimmunity in logistic regression models, adjusted for potential confounders. RESULTS: Growth patterns were not associated with islet autoimmunity in the whole dataset and in children of diabetic mothers, respectively. In children of non-diabetic mothers ,however, islet autoimmunity was associated with rapidly increasing BMI SDS values until the age of 3 yr [adjusted odds ratio (95% confidence interval): 2.02 (1.03, 3.73) for development of any islet autoantibodies) and with consistently above average height SDS values [odds ratio: 2.21 (1.15, 4.17)]. In contrast, a pattern of high height SDS values at birth followed by a decrease to average values after 3 yr was associated with a reduced rate of islet autoimmunity [odds ratio: 0.16 (0.01, 0.62)]. CONCLUSION: Early growth patterns may be associated with T1D-related islet autoimmunity risk in children of non-diabetic mothers.

Flexible Bayesian additive joint models with an application to type 1 diabetes research.

The joint modeling of longitudinal and time-to-event data is an important tool of growing popularity to gain insights into the association between a biomarker and an event process. We develop a general framework of flexible additive joint models that allows the specification of a variety of effects, such as smooth nonlinear, time-varying and random effects, in the longitudinal and survival parts of the models. Our extensions are motivated by the investigation of the relationship between fluctuating disease-specific markers, in this case autoantibodies, and the progression to the autoimmune disease type 1 diabetes. Using Bayesian P-splines, we are in particular able to capture highly nonlinear subject-specific marker trajectories as well as a time-varying association between the marker and event process allowing new insights into disease progression. The model is estimated within a Bayesian framework and implemented in the R-package bamlss.

Lactation is associated with altered metabolomic signatures in women with gestational diabetes.

AIMS/HYPOTHESIS: Lactation for >3 months in women with gestational diabetes is associated with a reduced risk of type 2 diabetes that persists for up to 15 years postpartum. However, the underlying mechanisms are unknown. We examined whether in women with gestational diabetes lactation for >3 months is associated with altered metabolomic signatures postpartum. METHODS: We enrolled 197 women with gestational diabetes at a median of 3.6 years (interquartile range 0.7-6.5 years) after delivery. Targeted metabolomics profiles (including 156 metabolites) were obtained during a glucose challenge test. Comparisons of metabolite concentrations and ratios between women who lactated for >3 months and women who lactated for ≤3 months or not at all were performed using linear regression with adjustment for age and BMI at the postpartum visit, time since delivery, and maternal education level, and correction for multiple testing. Gaussian graphical modelling was used to generate metabolite networks. RESULTS: Lactation for >3 months was associated with a higher total lysophosphatidylcholine/total phosphatidylcholine ratio; in women with short-term follow-up, it was also associated with lower leucine concentrations and a lower total branched-chain amino acid concentration. Gaussian graphical modelling identified subgroups of closely linked metabolites within phosphatidylcholines and branched-chain amino acids that were affected by lactation for >3 months and have been linked to the pathophysiology of type 2 diabetes in previous studies. CONCLUSIONS/INTERPRETATION: Lactation for >3 months in women with gestational diabetes is associated with changes in the metabolomics profile that have been linked to the early pathogenesis of type 2 diabetes.

Does charge-free screening improve detection of gestational diabetes in women from deprived areas: a cross-sectional study.

BACKGROUND: Gestational diabetes mellitus (GDM) occurs in 2-6 % of all pregnancies. We investigated whether area level deprivation is associated with a higher risk for GDM and whether GDM detection rates in deprived regions changed after the introduction of charge-free GDM screening in Germany in 2012. METHODS: We analyzed population-based data from Bavaria, Germany, comprising n = 587,621 deliveries in obstetric units between 2008 and 2014. Area level deprivation was assessed municipality-based using the Bavarian Index of Multiple Deprivation (BIMD), divided into quintiles and assigned to each mother based on her residential address. We estimated annual odds ratios (ORs) for GDM diagnosis by BIMD quintile with adjustment for maternal obesity, maternal age, migration background and single mother status. RESULTS: Women from the most deprived regions were less likely to be diagnosed with GDM before introduction of charge-free GDM screening (OR = 0.76 [95 % confidence interval: 0.66, 0.86] compared to least deprived areas), in 2008. In contrast, high area level deprivation was associated with significantly increased risk of GDM diagnosis in 2013 (OR [95 % confidence interval] = 1.15 [1.02, 1.29]). The OR was also elevated, although not significantly, in 2014 (OR [95 % confidence interval] = 1.05 [0.93, 1.18]). CONCLUSIONS: The prevalence of GDM seems to have been underreported in women from highly deprived areas before introduction of the charge-free GDM screening in Germany. In fact, women living in deprived regions seem to have an increased risk for GDM and may profit from access to charge-free GDM screening.

Islet autoantibody phenotypes and incidence in children at increased risk for type 1 diabetes.

AIMS/HYPOTHESIS: Autoantibodies that precede type 1 diabetes frequently develop in early childhood and target distinct beta cell proteins. The aim of this study was to determine the heterogeneity of islet autoantibody development and fate. METHODS: The ages of development of insulin autoantibodies (IAA) and GAD autoantibodies (GADA), followed by multiple islet autoantibodies and progression to diabetes were examined in 2,441 children participating in two German birth cohorts. RESULTS: In 218 children who developed islet autoantibodies, the first islet autoantibody-positive sample was characterised by single IAA in 80 (37%), multiple islet autoantibodies in 68 (31%) and single GADA in 63 (29%) children. Of the children who were single antibody positive at seroconversion, 35 (44%) IAA-positive and 15 (24%) GADA-positive children developed multiple islet autoantibodies. Single persistent antibodies had heterogeneous affinities; GADA were also heterogeneous in their binding to N-terminally truncated GAD65 and in an ELISA. Progression to diabetes occurred in >50% of children within 10 years in all groups that developed multiple islet autoantibodies and in 44% of children with persistent single high-affinity IAA or persistent single GADA that were positive in both a radiobinding assay and ELISA. The earliest autoantibody development was seen in children with single IAA that progressed to multiple islet autoantibodies or in those with persistent high-affinity single IAA, with a sharp peak in incidence observed at age 9 months. The peak incidence occurred at age 2 years for children who underwent seroconversion directly to multiple islet autoantibodies and at 5 years for children who first seroconverted to GADA and subsequently developed other autoantibodies. Seroconversion to low-affinity IAA or persistent single GADA occurred at a low incidence after the age of 9 months. CONCLUSIONS/INTERPRETATION: Children of different ages have differing susceptibilities to autoimmunisation against specific beta cell autoantigens.

Neonatal and infant beta cell hormone concentrations in relation to type 1 diabetes risk.

Type 1 diabetes is preceded by the appearance of islet autoantibodies. Seroconversion to islet autoantibodies is greatest around 1 yr of age and is more frequent in children born to fathers with type 1 diabetes as compared to children born to mothers with type 1 diabetes. Here we asked whether changes in beta-cell function in the neonate and infant reflect variations in the incidence of islet autoantibody seroconversion. Insulin, proinsulin, and c-peptide concentrations were measured in sequential samples taken from birth to age 2 yr in 103 children who had a first degree relative with type 1 diabetes and who had been followed for islet autoantibody seroconversion. Serum insulin and proinsulin concentrations were highest at birth declining by age 3 months and stable thereafter until age 2 yr. C-peptide concentrations, proinsulin/insulin, and proinsulin/c-peptide ratios were stable from age 3 months. No differences were observed between children who developed islet autoantibodies and children who remained islet autoantibody negative. Children born to a mother with type 1 diabetes had higher birth concentrations of insulin (p = 0.005) and proinsulin (p = 0.014) as compared with children of non-diabetic mothers. Increased insulin concentrations in children of type 1 diabetes mothers persisted until age 6 months. In conclusion, we could not relate excursions in beta-cell hormones to autoantibody development, but suggest that the higher exposure to insulin and proinsulin in neonates born to mothers with type 1 diabetes may be linked to the relative protection against islet autoantibody seroconversion observed in these children.

Early infant growth is associated with the risk of islet autoimmunity in genetically susceptible children.

BACKGROUND: Islet autoimmunity commonly develops early in infancy. We assessed whether specific parameters of early growth (including weight gain) were associated with the development of islet autoimmunity in children of type 1 diabetes patients, taking individual developmental patterns into account. METHODS: Growth parameters were estimated in n = 1011 children followed from birth in the prospective BABYDIAB and BABYDIET studies using longitudinal models. Cox proportional hazard models, adjusted for study, sex, gestational age, birth weight percentile, and maternal type 1 diabetes status, were calculated to assess hazard ratios (HR) for islet autoimmunity with corresponding 95% confidence intervals (95% CI) by 2 SD increases in growth parameters. In a subset of n = 170 infants, we investigated whether the growth hormones insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-binding protein-3 (IGFBP-3) were in the causal pathway. RESULTS: We found an early age at infant body mass index (BMI) peak to be associated with the development of islet autoimmunity [HR 0.60 (95% CI 0.41-0.87), per 2 SD increase in age]. Islet autoimmunity was also associated with BMI difference between infant BMI peak and childhood BMI rebound [HR 1.52 (95% CI 1.04-2.22)], but not after adjustment for age at infant BMI peak, and not with other parameters such as peak height and weight velocity during infancy. Serum concentrations of IGF-1 and IGFBP-3 at birth, 9 months, and 2 yr, respectively, were not significantly different between children with and without later islet autoimmunity. CONCLUSIONS: Variations in early growth rate have subtle effects on the risk of islet autoimmunity with growth hormones unlikely to be in the causal pathway.