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Background: The Environmental Determinants of Islet Autoimmunity (ENDIA) pregnancy-birth cohort investigates the developmental origins of type 1 diabetes (T1D), with recruitment between 2013 and 2019. ENDIA is the first study in the world with comprehensive data and biospecimen collection during pregnancy, at birth and through childhood from at-risk children who have a first-degree relative with T1D. Environmental exposures are thought to drive the progression to clinical T1D, with pancreatic islet autoimmunity (IA) developing in genetically susceptible individuals. The exposures and key molecular mechanisms driving this progression are unknown. Persistent IA is the primary outcome of ENDIA; defined as a positive antibody for at least one of IAA, GAD, ZnT8 or IA2 on two consecutive occasions and signifies high risk of clinical T1D. Method: A nested case-control (NCC) study design with 54 cases and 161 matched controls aims to investigate associations between persistent IA and longitudinal omics exposures in ENDIA. The NCC study will analyse samples obtained from ENDIA children who have either developed persistent IA or progressed to clinical T1D (cases) and matched control children at risk of developing persistent IA. Control children were matched on sex and age, with all four autoantibodies absent within a defined window of the case's onset date. Cases seroconverted at a median of 1.37 years (IQR 0.95, 2.56). Longitudinal omics data generated from approximately 16,000 samples of different biospecimen types, will enable evaluation of changes from pregnancy through childhood. Conclusions: This paper describes the ENDIA NCC study, omics platform design considerations and planned univariate and multivariate analyses for its longitudinal data. Methodologies for multivariate omics analysis with longitudinal data are discovery-focused and data driven. There is currently no single multivariate method tailored specifically for the longitudinal omics data that the ENDIA NCC study will generate and therefore omics analysis results will require either cross validation or independent validation. The ENDIA nested case-control study will utilize longitudinal omics data on approximately 16,000 samples from 190 unique children at risk of type 1 diabetes (T1D), including 54 who have developed islet autoimmunity (IA), followed during pregnancy, at birth and during early childhood, enabling the developmental origins of T1D to be explored. [ABSTRACT FROM AUTHOR]

Backgrounds: We aimed to monitor pancreatic exocrine function longitudinally in relation to the development of islet autoimmunity (IA) and type 1 diabetes (T1D) in at‐risk children with a first‐degree relative with T1D, who were followed prospectively in the Environmental Determinants of Islet Autoimmunity (ENDIA) study. Methods: Fecal elastase‐1 (FE‐1) concentration was measured longitudinally in 85 ENDIA children from median age 1.0 (IQR 0.7,1.3) year. Twenty‐eight of 85 children (progressors) developed persistent islet autoantibodies at median age of 1.5 (IQR 1.1,2.5) years, of whom 11 went on to develop clinical diabetes. The other 57 islet autoantibody‐negative children (non‐progressors) followed similarly were age and gender‐matched with the progressors. An adjusted linear mixed model compared FE‐1 concentrations in progressors and non‐progressors. Results: Baseline FE‐1 did not differ between progressors and non‐progressors, or by HLA DR type or proband status. FE‐1 decreased over time in progressors in comparison to non‐progressors (Wald statistic 5.46, P =.02); in some progressors the fall in FE‐1 preceded the onset of IA. Conclusions: Pancreatic exocrine function decreases in the majority of young at‐risk children who progress to IA and T1D. [ABSTRACT FROM AUTHOR]

Background: Microbial exposures in utero and early life shape the infant microbiome, which can profoundly impact on health. Compared to the bacterial microbiome, very little is known about the virome. We set out to characterize longitudinal changes in the gut virome of healthy infants born to mothers with or without type 1 diabetes using comprehensive virome capture sequencing. Methods: Healthy infants were selected from Environmental Determinants of Islet Autoimmunity (ENDIA), a prospective cohort of Australian children with a first‐degree relative with type 1 diabetes, followed from pregnancy. Fecal specimens were collected three‐monthly in the first year of life. Results: Among 25 infants (44% born to mothers with type 1 diabetes) at least one virus was detected in 65% (65/100) of samples and 96% (24/25) of infants during the first year of life. In total, 26 genera of viruses were identified and >150 viruses were differentially abundant between the gut of infants with a mother with type 1 diabetes vs without. Positivity for any virus was associated with maternal type 1 diabetes and older infant age. Enterovirus was associated with older infant age and maternal smoking. Conclusions: We demonstrate a distinct gut virome profile in infants of mothers with type 1 diabetes, which may influence health outcomes later in life. Higher prevalence and greater number of viruses observed compared to previous studies suggests significant underrepresentation in existing virome datasets, arising most likely from less sensitive techniques used in data acquisition. [ABSTRACT FROM AUTHOR]

Aims/hypothesis: To investigate the longitudinal relationship between the gut microbiome, circulating short chain fatty acids (SCFAs) and intestinal permeability in children with islet autoimmunity or type 1 diabetes and controls. Methods: We analyzed the gut bacterial microbiome, plasma SCFAs, small intestinal permeability and dietary intake in 47 children with islet autoimmunity or recent‐onset type 1 diabetes and in 41 unrelated or sibling controls over a median (range) of 13 (2‐34) months follow‐up. Results: Children with multiple islet autoantibodies (≥2 IA) or type 1 diabetes had gut microbiome dysbiosis. Anti‐inflammatory Prevotella and Butyricimonas genera were less abundant and these changes were not explained by differences in diet. Small intestinal permeability measured by blood lactulose:rhamnose ratio was higher in type 1 diabetes. Children with ≥2 IA who progressed to type 1 diabetes (progressors), compared to those who did not progress, had higher intestinal permeability (mean [SE] difference +5.14 [2.0], 95% confidence interval [CI] 1.21, 9.07, P =.006), lower within‐sample (alpha) microbial diversity (31.3 [11.2], 95% CI 9.3, 53.3, P =.005), and lower abundance of SCFA‐producing bacteria. Alpha diversity (observed richness) correlated with plasma acetate levels in all groups combined (regression coefficient [SE] 0.57 [0.21], 95% CI 0.15, 0.99 P =.008). Conclusions/Interpretation: Children with ≥2 IA who progress to diabetes, like those with recent‐onset diabetes, have gut microbiome dysbiosis associated with increased intestinal permeability. Interventions that expand gut microbial diversity, in particular SCFA‐producing bacteria, may have a role to decrease progression to diabetes in children at‐risk. [ABSTRACT FROM AUTHOR]

Aims/hypothesis: Beta cell function in type 1 diabetes is commonly assessed as the average plasma C-peptide concentration over 2 h following a mixed-meal test (CPAVE). Monitoring of disease progression and response to disease-modifying therapy would benefit from a simpler, more convenient and less costly measure. Therefore, we determined whether CPAVE could be reliably estimated from routine clinical variables.Methods: Clinical and fasting biochemical data from eight randomised therapy trials involving participants with recently diagnosed type 1 diabetes were used to develop and validate linear models to estimate CPAVE and to test their accuracy in estimating loss of beta cell function and response to immune therapy.Results: A model based on disease duration, BMI, insulin dose, HbA1c, fasting plasma C-peptide and fasting plasma glucose most accurately estimated loss of beta cell function (area under the receiver operating characteristic curve [AUROC] 0.89 [95% CI 0.87, 0.92]) and was superior to the commonly used insulin-dose-adjusted HbA1c (IDAA1c) measure (AUROC 0.72 [95% CI 0.68, 0.76]). Model-estimated CPAVE (CPEST) reliably identified treatment effects in randomised trials. CPEST, compared with CPAVE, required only a modest (up to 17%) increase in sample size for equivalent statistical power.Conclusions/interpretation: CPEST, approximated from six variables at a single time point, accurately identifies loss of beta cell function in type 1 diabetes and is comparable to CPAVE for identifying treatment effects. CPEST could serve as a convenient and economical measure of beta cell function in the clinic and as a primary outcome measure in trials of disease-modifying therapy in type 1 diabetes. [ABSTRACT FROM AUTHOR]

Background/Objective: Adolescents with type 1 diabetes have early macrovascular changes (increased intima‐media thickness [IMT]) and early retinal changes that predict clinical disease in adulthood. We hypothesized that early changes in the macrovascular and retinal microvascular beds develop in parallel before retinopathy develops. We therefore aimed to investigate the relationship between changes in atherosclerosis (carotid and aortic IMT) and retinal vascular geometry cross‐sectionally and longitudinally in adolescents with type 1 diabetes. Methods: Ninety adolescents with type 1 diabetes (41 boys, aged 13.6 ± 3.5 years) who were enrolled in a randomized controlled trial had evaluations at baseline; 41 randomized to placebo were also investigated at 12 months for carotid and aortic IMT using ultrasound and retinal vascular geometry was measured from retinal photographs. Results: There were significant associations between thicker mean/maximum carotid IMT and wider retinal arteriolar and venular calibers; for every 0.1 mm increase in mean carotid IMT, retinal arteriolar caliber increased by 7.90 μm (95% confidence interval [CI] 4.50, 11.30, P < 0.0001) and venular caliber by 9.61 μm (95% CI 4.16, 15.06, P = 0.0008). Increased mean aortic IMT was associated with increased arteriolar tortuosity (2.61, 95% CI 0.50, 4.71, P = 0.02). Conclusions: The early changes of atherosclerosis are associated with retinal microvascular changes in adolescents with type 1 diabetes. This supports parallel adverse changes in the macro and microvascular circulations from early adolescence in type 1 diabetes, and highlights the importance of early intervention. [ABSTRACT FROM AUTHOR]

Background and Objective: Children with type 1 diabetes (T1D) have vascular dysfunction and frequently struggle to adhere to dietary recommendations. Limited data exist for the vascular consequences of poor diet quality in children. We aimed to evaluate the association between dietary components and vascular function in children with T1D. Methods: Cross‐sectional study including 90 children (13.6 [3.5] years, 41 boys) with T1D. They had evaluation of dietary micro and macronutrients (Australian Child and Adolescent Eating Survey), vascular endothelial and smooth muscle function (flow‐mediated dilatation and glyceryl trinitrate mediated dilatation [GTN], respectively), clinical and biochemical variables. Results: Children had a sodium intake of 3.013 (0.76) (mean [SD]) g/day. Vascular smooth muscle dysfunction, as measured by GTN, related to higher daily sodium intake (r = −0.31, P = .003), independent of the inverse relationships between GTN and total energy (r = −0.30, P = .005) and fat intake (r = −0.28, P = .007). Multiregression model showed that an increase in 1 g of daily sodium intake was independently associated with a deterioration of 3 percentage units in GTN (95% CI −4.3, −0.9; P = .003). There was an association between sodium intake and systolic blood pressure after adjustment for age and gender (regression coefficient 2.4; 95% CI 0.5, 4.3; P = .01). Conclusions: High dietary sodium intake in children with T1D is common and relates to vascular dysfunction, independently of other dietary intake, blood pressure, and glycemic control. [ABSTRACT FROM AUTHOR]

Background The importance of gut bacteria in human physiology, immune regulation, and disease pathogenesis is well established. In contrast, the composition and dynamics of the gut virome are largely unknown; particularly lacking are studies in pregnancy. We used comprehensive virome capture sequencing to characterize the gut virome of pregnant women with and without type 1 diabetes (T1D), longitudinally followed in the Environmental Determinants of Islet Autoimmunity study. Methods In total, 61 pregnant women (35 with T1D and 26 without) from Australia were examined. Nucleic acid was extracted from serial fecal specimens obtained at prenatal visits, and viral genomes were sequenced by virome capture enrichment. The frequency, richness, and abundance of viruses were compared between women with and without T1D. Results Two viruses were more prevalent in pregnant women with T1D: picobirnaviruses (odds ratio [OR], 4.2; 95% confidence interval [CI], 1.0–17.1; P =.046) and tobamoviruses (OR, 3.2; 95% CI, 1.1–9.3; P =.037). The abundance of 77 viruses significantly differed between the 2 maternal groups (≥2-fold difference; P <.02), including 8 Enterovirus B types present at a higher abundance in women with T1D. Conclusions These findings provide novel insight into the composition of the gut virome during pregnancy and demonstrate a distinct profile of viruses in women with T1D. [ABSTRACT FROM AUTHOR]

The article focuses on a study which aims to determine the relationship between activity levels and intima-media thickness (MT) in children with type 1 diabetes. It examines the link of children's lower activity levels to thicker IMT as well as provides an overview of vascular structural changes, such as increased carotid and aortic IMT.