Heterogeneity of DKA Incidence and Age-Specific Clinical Characteristics in Children Diagnosed With Type 1 Diabetes in the TEDDY Study

OBJECTIVE

The Environmental Determinants of Diabetes in the Young (TEDDY) study is uniquely capable of investigating age-specific differences associated with type 1 diabetes. Because age is a primary driver of heterogeneity in type 1 diabetes, we sought to characterize by age metabolic derangements prior to diagnosis and clinical features associated with diabetic ketoacidosis (DKA).

RESEARCH DESIGN AND METHODS

The 379 TEDDY children who developed type 1 diabetes were grouped by age at onset (0-4, 5-9, and 10-14 years; n = 142, 151, and 86, respectively) with comparisons of autoantibody profiles, HLAs, family history of diabetes, presence of DKA, symptomatology at onset, and adherence to TEDDY protocol. Time-varying analysis compared those with oral glucose tolerance test data with TEDDY children who did not progress to diabetes.

RESULTS

Increasing fasting glucose (hazard ratio [HR] 1.09 [95% CI 1.04-1.14]; P = 0.0003), stimulated glucose (HR 1.50 [1.42-1.59]; P < 0.0001), fasting insulin (HR 0.89 [0.83-0.95]; P = 0.0009), and glucose-to-insulin ratio (HR 1.29 [1.16-1.43]; P < 0.0001) were associated with risk of progression to type 1 diabetes. Younger children had fewer autoantibodies with more symptoms at diagnosis. Twenty-three children (6.1%) had DKA at onset, only 1 (0.97%) of 103 with and 22 (8.0%) of 276 children without a first-degree relative (FDR) with type 1 diabetes (P = 0.008). Children with DKA were more likely to be nonadherent to study protocol (P = 0.047), with longer duration between their last TEDDY evaluation and diagnosis (median 10.2 vs. 2.0 months without DKA; P < 0.001).

CONCLUSIONS

DKA at onset in TEDDY is uncommon, especially for FDRs. For those without familial risk, metabolic monitoring continues to provide a primary benefit of reduced DKA but requires regular follow-up. Clinical and laboratory features vary by age at onset, adding to the heterogeneity of type 1 diabetes.

Parental monitoring for type 1 diabetes in genetically at-risk young children: The TEDDY study

OBJECTIVE

We examined parental diabetes monitoring behaviors in a cohort of children at increased genetic risk for type 1 diabetes. We hypothesized that being informed of a positive islet autoantibody (IA) would increase monitoring behaviors.

RESEARCH DESIGN AND METHODS

The Environmental Determinants of Diabetes in the Young (TEDDY) study follows 8676 children with high-risk human leucocyte antigen-DQ genotypes from birth to age 15, including general population (GP) children and those with a first-degree relative (FDR) with diabetes. Data on parental monitoring behaviors were solicited yearly. Serum samples were tested for IA and parents were informed of child results. We examined parental monitoring behaviors during the first 7 years of TEDDY.

RESULTS

In IA- children, the most common monitoring behavior was participating in TEDDY study tasks; up to 49.8% and 44.2% of mothers and fathers, respectively, reported this. Among FDRs, 7%-10% reported watching for diabetes symptoms and 7%-9% reported monitoring the child's glucose, for mothers and fathers, respectively. After IA+ notification, all monitoring behaviors significantly increased in GP parents; only glucose monitoring increased in FDR parents and these behaviors continued for up to 4 years. FDR status, accurate diabetes risk perception, and anxiety were associated with glucose monitoring in IA+ and IA- cohorts.

CONCLUSIONS

Many parents view TEDDY participation as a way to monitor for type 1 diabetes, a benefit of enrollment in a longitudinal study with no prevention offered. IA+ notification increases short- and long-term monitoring behaviors. For IA- and IA+ children, FDR parents engage in glucose monitoring, even when not instructed to do so.

Complete blood counts with red blood cell determinants associate with reduced beta-cell function in seroconverted Swedish TEDDY children

OBJECTIVES

To investigate whether changes in complete blood count (CBC) in islet autoantibody positive children with increased genetic risk for type 1 diabetes are associated with oral glucose tolerance tests (OGTT) and HbA1c over time.

METHODS

The Environmental Determinants of Diabetes in the Young (TEDDY) study follows children with increased risk for type 1 diabetes in the United States, Germany, Sweden and Finland. In the current study, 89 Swedish TEDDY children (median age 8.8 years) positive for one or multiple islet autoantibodies were followed up to 5 (median 2.3) years for CBC, OGTT and HbA1c. A statistical mixed effect model was used to investigate the association between CBC and OGTT or HbA1c.

RESULTS

HbA1c over time increased by the number of autoantibodies (p < .001). Reduction in mean corpuscular haemoglobin (MCH) and mean cell volume (MCV) was both associated with an increase in HbA1c (p < .001). A reduction in red blood cell (RBC) counts (p = .003), haemoglobin (p = .002) and haematocrit (p = .006) levels was associated with increased fasting glucose. Increased red blood cells, haemoglobin, haematocrit and MCH but decreased levels of red blood cell distribution widths (RDW) were all associated with increased fasting insulin.

CONCLUSIONS

The decrease in RBC indices with increasing HbA1c and the decrease in RBC and its parameters with increasing fasting glucose in seroconverted children may reflect an insidious deterioration in glucose metabolism associated with islet beta-cell autoimmunity.

Adherence to oral glucose tolerance testing in children in stage 1 of type 1 diabetes: The TEDDY study

OBJECTIVE

To examine adherence to the oral glucose tolerance test (OGTT) in multiple islet autoantibody children in stage 1 of developing type 1 diabetes (T1D).

METHODS

Children are followed from birth in The Environmental Determinants of Diabetes in the Young (TEDDY) study. Completion of an OGTT is recommended every 6 months in children ≥3 years of age who are multiple islet autoantibody positive. Factors associated with adherence to the OGTT protocol were examined.

RESULTS

The average subject level adherence with the OGTT protocol was 62% although there were large differences across countries; Finnish participants and older children from Sweden were more adherent than participants from the United States and Germany. Factors associated with nonadherence included having a first-degree relative with T1D, using a local laboratory rather than a TEDDY center for the OGTT, and maternal underestimation of the child's risk for T1D. Children were more adherent to the OGTT if their mothers: were more satisfied with TEDDY participation, reported monitoring the child for T1D by checking blood glucose levels at home, and viewed participating in TEDDY as the primary way they were monitoring the child for T1D.

CONCLUSIONS

In a study of children in stage 1 of T1D, adherence to an OGTT protocol was suboptimal despite extensive efforts to communicate the child's high risk to parents. These findings provide important guidance for development of strategies to improve methods for detecting progression or the development of T1D in high-risk pediatric populations.

The association between stressful life events and respiratory infections during the first 4 years of life: The Environmental Determinants of Diabetes in the Young study

The aim of this study was to conduct a prospective analysis of the association between negative life events (NLEs) and respiratory infections in children genetically at risk for islet autoimmunity (IA) and type 1 diabetes (T1D). Long- and short-term temporal associations between NLEs and rate of respiratory infection episodes (RIEs) in 5,618 children in The Environmental Determinants of Diabetes in the Young study for at least 1 up to 4 years were analysed. All models were adjusted for demographic, day care, season of infection, and psychosocial factors associated with the rate of child RIEs between study visits. The rate of child RIEs was 26% higher in Europe (Sweden, Finland, Germany) than in the United States (rate ratio [RR] = 1.26, p < 0.001). However, the percentage of child NLEs (odds ratio [OR] = 1.18, p < 0.001) and mother NLEs (OR = 1.83, p < 0.001) was higher in the United States compared with Europe. In both continents (Europe, RR = 1.12, p < 0.001; United States, RR = 1.07, p = 0.006), high child cumulative NLEs (>1 NLE per year since study inception) was significantly associated with an increased rate of child RIEs. This large-scale prospective study confirms observations that stress may increase the susceptibility for infections in paediatric populations and suggests at least one mechanism by which stress could increase risk for IA and T1D in genetically at risk children.

Maternal dietary supplement use and development of islet autoimmunity in the offspring: TEDDY study

OBJECTIVE

We investigated the association between maternal use of vitamin D and omega-3 fatty acids (n-3 FAs) supplements during pregnancy and risk of islet autoimmunity (IA) in the offspring.

METHODS

The Environmental Determinants of Diabetes in the Young (TEDDY) Study is prospectively following 8676 children with increased genetic risk for type 1 diabetes in Finland, Germany, Sweden, and the United States. Blood samples were collected every 3 months between 3 and 48 months of age then every 6 months thereafter to determine persistent IA. Duration, frequency, and supplement dose during pregnancy were recalled by mothers at 3 to 4 months postpartum. Cumulative intakes of supplemental vitamin D and n-3 FAs were analyzed as continuous or binary variables. We applied time-to-event analysis to study the association between maternal supplement use and IA, adjusting for country, human leukocyte antigen-DR-DQ genotype, family history of type 1 diabetes and sex. Secondary outcomes included insulin autoantibodies (IAA) or glutamic acid decarboxylase (GADA) as the first appearing autoantibody.

RESULTS

As of February 2018, there were 747 (9.0%) children with IA. Vitamin D supplement intake during pregnancy (any vs none) was not associated with risk for IA (hazard ratio [HR] 1.11; 95% confidence interval [CI] 0.94, 1.31); neither was cumulative vitamin D supplement intake. Supplemental n-3 FA intake was similarly not associated with IA risk (HR: 1.19, 95% CI 0.98, 1.45). Similar lack of association was observed for either IAA or GADA as the first appearing autoantibody.

CONCLUSIONS

The TEDDY cohort showed no evidence of benefit regarding IA risk for vitamin D or n-3 FA supplementation during pregnancy.

Early Infant Diet and Islet Autoimmunity in the TEDDY Study

OBJECTIVE

To examine duration of breastfeeding and timing of complementary foods and risk of islet autoimmunity (IA).

RESEARCH DESIGN AND METHODS

The Environmental Determinants of Diabetes in the Young (TEDDY) study prospectively follows 8,676 children with increased genetic risk of type 1 diabetes (T1D) in the U.S., Finland, Germany, and Sweden. This study included 7,563 children with at least 9 months of follow-up. Blood samples were collected every 3 months from birth to evaluate IA, defined as persistent, confirmed positive antibodies to insulin (IAAs), GAD, or insulinoma antigen-2. We examined the associations between diet and the risk of IA using Cox regression models adjusted for country, T1D family history, HLA genotype, sex, and early probiotic exposure. Additionally, we investigated martingale residuals and log-rank statistics to determine cut points for ages of dietary exposures.

RESULTS

Later introduction of gluten was associated with increased risk of any IA and IAA. The hazard ratios (HRs) for every 1-month delay in gluten introduction were 1.05 (95% CI 1.01, 1.10; P = 0.02) and 1.08 (95% CI 1.00, 1.16; P = 0.04), respectively. Martingale residual analysis suggested that the age at gluten introduction could be grouped as <4, 4-9, and >9 months. The risk of IA associated with introducing gluten before 4 months of age was lower (HR 0.68; 95% CI 0.47, 0.99), and the risk of IA associated with introducing it later than the age of 9 months was higher (HR 1.57; 95% CI 1.07, 2.31) than introduction between 4 and 9 months of age.

CONCLUSIONS

The timing of gluten-containing cereals and IA should be studied further.

Development of a harmonized food grouping system for between-country comparisons in the TEDDY Study

The Environmental Determinants of Diabetes in the Young (TEDDY) is an international study aiming to investigate associations between dietary and other environmental factors and the risk of developing islet autoimmunity and type 1 diabetes. Dietary intake was assessed using a 24-hour recall and repeated 3-day food records and analyzed using country-specific food composition databases (FCDBs) in Finland, Germany, Sweden, and the U.S. with respective in-house calculation programs. A food grouping harmonization process between four country-specific FCDBs was conducted to evaluate and achieve comparability on food group definitions and quantification of food consumption across the countries. Systematic review revealed that the majority of existing food groups of the TEDDY FCDBs were not comparable. Therefore, a completely new classification system of 15 mutually exclusive main food groups (e.g. vegetables) and 89 subgroups (e.g. root vegetables, leafy vegetables) was developed. Foods and beverages were categorized into basic foods (single ingredient) and composite dishes (multiple ingredients). Composite dishes were broken down to ingredients using food composition data available in the FCDBs or generic recipes created for the harmonization effort. The daily consumption of every food group across FCDBs was quantified consistently as either raw or prepared weight depending on the food group to achieve maximal comparability.

Maternal anxiety about a child's diabetes risk in the TEDDY study: the potential role of life stress, postpartum depression, and risk perception

OBJECTIVE

To understand the association between life stress, postpartum depression (PD), maternal perception of her child's risk for type 1 diabetes (T1D) and a mother's anxiety about her child's T1D risk in mothers of genetically at risk children in The Environmental Determinants of Diabetes in the Young (TEDDY) study.

METHODS

A short form of the state component (SAI) of the State-Trait Anxiety Inventory, negative life events (LE), the Edinburgh Postnatal Depression Scale (EPDS), and one question about the child's risk of developing T1D risk perceptions (RP) were given to mothers at the 6-month TEDDY clinic visit. The relationship between the four measures was modeled using multiple regressions.

RESULTS

Controlling for sociodemographic factors, significant country differences in SAI, LE, EPDS, and RP emerged. LE - particularly interpersonal LE - had a strong association to maternal anxiety about the baby's risk of diabetes. Both evidence of PD and accurate risk perceptions (RPs) about the child's T1D risk were associated with increased maternal anxiety about the child's T1D risk.

CONCLUSION

Heightened maternal anxiety in response to the news that a child is at increased risk for T1D is common. Mothers who have experienced recent negative LE, who experience PD and who accurately understand their child's risk may be particularly vulnerable to high levels of anxiety. The findings reported here need to be confirmed in future prospective studies.

HLA-DPB1*04:01 Protects Genetically Susceptible Children from Celiac Disease Autoimmunity in the TEDDY Study

OBJECTIVES

Tissue transglutaminase autoantibodies (tTGAs) represent the first evidence of celiac disease (CD) development. Associations of HLA-DR3-DQA1*05:01-DQB1*02:01 (i.e., DR3-DQ2) and, to a lesser extent, DR4-DQA1*03:01-DQB1*03:02 (i.e., DR4-DQ8) with the risk of CD differ by country, consistent with additional genetic heterogeneity that further refines risk. Therefore, we examined human leukocyte antigen (HLA) factors other than DR3-DQ2 for their contribution to developing tTGAs.

METHODS

The Environmental Determinants of Diabetes in the Young (TEDDY) study enrolled 8,676 infants at an increased HLA-DR-DQ risk for type 1 diabetes and CD into a 15-year prospective surveillance follow-up. Of those followed up, 21% (n=1,813) carried DR3-DQ2/DR3-DQ2, 39% (n=3,359) carried DR3-DQ2/DR4-DQ8, 20% (n=1701) carried DR4-DQ8/DR4-DQ8, and 17% (n=1,493) carried DR4-DQ8/DQ4. Within TEDDY, a nested case-control design of 248 children with CD autoimmunity (CDA) and 248 matched control children were genotyped for HLA-B, -DRB3, -DRB4, -DPA1, and -DPB1 genes, and the entire cohort was genotyped for single-nucleotide polymorphisms (SNPs) using the Illumina ImmunoChip. CDA was defined as a positive tTGA test at two consecutive clinic visits, whereas matching in those with no evidence of tTGAs was based on the presence of HLA-DQ2, country, and sex.

RESULTS

After adjustment for DR3-DQ2 and restriction to allele frequency (AF) ≥5%, HLA-DPB1*04:01 was inversely associated with CDA by conditional logistic regression (AF=44%, odds ratio=0.71, 95% confidence interval (CI)=0.53-0.96, P=0.025). This association of time to CDA and HLA-DPB1*04:01 was replicated with statistical significance in the remainder of the cohort using imputation for specific HLA alleles based on SNP genotyping (hazard ratio=0.84, 95% CI=0.73-0.96, P=0.013).

CONCLUSIONS

HLA-DPB1*04:01 may reduce the risk of tTGAs, an early marker of CD, among DR3-DQ2 children, confirming that additional variants in the HLA region influence the risk for CDA.

Prevalence of obesity was related to HLA-DQ in 2-4-year-old children at genetic risk for type 1 diabetes

OBJECTIVES

Body size is postulated to modulate type 1 diabetes as either a trigger of islet autoimmunity or an accelerator to clinical onset after seroconversion. As overweight and obesity continue to rise among children, the aim of this study was to determine whether human leukocyte antigen DQ (HLA-DQ) genotypes may be related to body size among children genetically at risk for type 1 diabetes.

METHODS

Repeated measures of weight and height were collected from 5969 children 2-4 years of age enrolled in The Environmental Determinants of Diabetes in the Young prospective study. Overweight and obesity was determined by the International Obesity Task Force cutoff values that correspond to body mass index (BMI) of 25 and 30 kg m(-)(2) at age 18.

RESULTS

The average BMI was comparable across specific HLA genotypes at every age point. The proportion of overweight was not different by HL A, but percent obesity varied by age with a decreasing trend among DQ2/8 carriers (P for trend=0.0315). A multivariable regression model suggested DQ2/2 was associated with higher obesity risk at age 4 (odds ratio, 2.41; 95% confidence interval, 1.21-4.80) after adjusting for the development of islet autoantibody and/or type 1 diabetes.

CONCLUSIONS

The HLA-DQ2/2 genotype may predispose to obesity among 2-4-year-old children with genetic risk for type 1 diabetes.

Methods, quality control and specimen management in an international multicentre investigation of type 1 diabetes: TEDDY

BACKGROUND

The vast array and quantity of longitudinal samples collected in The Environmental Determinants of Diabetes in the Young study present a series of challenges in terms of quality control procedures and data validity. To address this, pilot studies have been conducted to standardize and enhance both biospecimen collection and sample obtainment in terms of autoantibody collection, stool sample preservation, RNA, biomarker stability, metabolic biomarkers and T-cell viability.

RESEARCH DESIGN AND METHODS

The Environmental Determinants of Diabetes in the Young is a multicentre, international prospective study (n = 8677) designed to identify environmental triggers of type 1 diabetes (T1D) in genetically at-risk children from ages 3 months until 15 years. The study is conducted through six primary clinical centres located in four countries.

RESULTS

As of May 2012, over three million biological samples and 250 million total data points have been collected, which will be analysed to assess autoimmunity status, presence of inflammatory biomarkers, genetic factors, exposure to infectious agents, dietary biomarkers and other potentially important environmental exposures in relation to autoimmunity and progression to T1D.

CONCLUSIONS

Detailed procedures were utilized to standardize both data harmonization and management when handling a large quantity of longitudinal samples obtained from multiple locations. In addition, a description of the available specimens is provided that serve as an invaluable repository for the elucidation of determinants in T1D focusing on autoantibody concordance and harmonization, transglutaminase autoantibody, inflammatory biomarkers (T-cells), genetic proficiency testing, RNA lab internal quality control testing, infectious agents (monitoring cross-contamination, virus preservation and nasal swab collection validity) and HbA1c testing.