Family history of diabetes and distribution of class II HLA genotypes in children with newly diagnosed type 1 diabetes: effect on diabetic ketoacidosis

Next-generation sequencing reveals additional HLA class I and class II alleles associated with type 1 diabetes and age at onset

Introduction

Type 1 diabetes is an autoimmune disease with an significant genetic component, played mainly by the HLA class II genes. Although evidence on the role of HLA class I genes in developing type 1 diabetes and its onset have emerged, current HLA screening is limited to determining DR3 and DR4 haplotypes. This study aimed to investigate the role of HLA genes on type 1 diabetes risk and age of onset by extensive typing.

Methods

This study included 115 children and young adults with type 1 diabetes for whom typing of HLA-A, -B, -C, -DRB1, -DRB3/4/5, -DQA1, -DQB1, -DPA1 and -DPB1 genes was conducted using Next Generation Sequencing.

Results

We observed that 13% of type 1 diabetes subjects had non-classical HLA haplotypes that predispose to diabetes. We also found that compared to type 1 diabetes subjects with classical HLA haplotypes, non-classical HLA subjects had a significantly higher frequency of HLA-B*39:06:02 (p-value=0.01) and HLA-C*07:02:01 (p-value=0.03) alleles, known to be involved in activating the immune response. Non-classical HLA subjects also presented peculiar clinical features compared to classical HLA subjects, such as multiple diabetic antibodies and the absence of other autoimmune diseases (i.e., coeliac disease and thyroiditis). We also observed that subjects with early onset had a higher frequency of DQ2/DQ8 genotype than late-onset individuals. Moreover, subjects with late-onset had a higher frequency of alleles HLA-B*27 (p-value=0.003), HLA-C*01:02:01 (p-value=0.027) and C*02:02:02 (p-value=0.01), known to be associated with increased protection against viral infections.

Discussion

This study reveals a broader involvement of the HLA locus in the development and onset of type 1 diabetes, providing insights into new possible disease prevention and management strategies.

Maternal type 1 diabetes and relative protection against offspring transmission

Type 1 diabetes is around twice as common in the offspring of men with type 1 diabetes than in the offspring of women with type 1 diabetes, but the reasons for this difference are unclear. This Review summarises the evidence on the rate of transmission of type 1 diabetes to the offspring of affected fathers compared with affected mothers. The findings of nine major studies are presented, describing the magnitude of the effect observed and the relative strengths and weaknesses of these studies. This Review also explores possible underlying mechanisms for this effect, such as genetic mechanisms (eg, the selective loss of fetuses with high-risk genes in mothers with type 1 diabetes, preferential transmission of susceptibility genes from fathers, and parent-of-origin effects influencing gene expression), environmental exposures (eg, exposure to maternal hyperglycaemia, exogenous insulin exposure, and transplacental antibody transfer), and maternal microchimerism. Understanding why type 1 diabetes is more common in the offspring of men versus women with type 1 diabetes will help in the identification of individuals at high risk of the disease and can pave the way in the development of interventions that mimic the protective elements of maternal type 1 diabetes to reduce the risk of disease in individuals at high risk.

Residual insulin secretion in individuals with type 1 diabetes in Finland: longitudinal and cross-sectional analyses

BACKGROUND

Contrary to the presumption that type 1 diabetes leads to an absolute insulin deficiency, many individuals with type 1 diabetes have circulating C-peptide years after the diagnosis. We studied factors affecting random serum C-peptide concentration in individuals with type 1 diabetes and the association with diabetic complications.

METHODS

Our longitudinal analysis included individuals newly diagnosed with type 1 diabetes from Helsinki University Hospital (Helsinki, Finland) with repeated random serum C-peptide and concomitant glucose measurements from within 3 months of diagnosis and at least once later. The long-term cross-sectional analysis included data from participants from 57 centres in Finland who had type 1 diabetes diagnosed after 5 years of age, initiation of insulin treatment within 1 year from diagnosis, and a C-peptide concentration of less than 1·0 nmol/L (FinnDiane study) and patients with type 1 diabetes from the DIREVA study. We tested the association of random serum C-peptide concentrations and polygenic risk scores with one-way ANOVA, and association of random serum C-peptide concentrations, polygenic risk scores, and clinical factors with logistic regression.

FINDINGS

The longitudinal analysis included 847 participants younger than 16 years and 110 aged 16 years or older. In the longitudinal analysis, age at diagnosis strongly correlated with the decline in C-peptide secretion. The cross-sectional analysis included 3984 participants from FinnDiane and 645 from DIREVA. In the cross-sectional analysis, at a median duration of 21·6 years (IQR 12·5-31·2), 776 (19·4%) of 3984 FinnDiane participants had residual random serum C-peptide secretion (>0·02 nmol/L), which was associated with lower type 1 diabetes polygenic risk compared with participants without random serum C-peptide (p<0·0001). Random serum C-peptide was inversely associated with hypertension, HbA1c, and cholesterol, but also independently with microvascular complications (adjusted OR 0·61 [95% CI 0·38-0·96], p=0·033, for nephropathy; 0·55 [0·34-0·89], p=0·014, for retinopathy).

INTERPRETATION

Although children with multiple autoantibodies and HLA risk genotypes progressed to absolute insulin deficiency rapidly, many adolescents and adults had residual random serum C-peptide decades after the diagnosis. Polygenic risk of type 1 and type 2 diabetes affected residual random serum C-peptide. Even low residual random serum C-peptide concentrations seemed to be associated with a beneficial complications profile.

FUNDING

Folkhälsan Research Foundation; Academy of Finland; University of Helsinki and Helsinki University Hospital; Medical Society of Finland; the Sigrid Juselius Foundation; the "Liv and Hälsa" Society; Novo Nordisk Foundation; and State Research Funding via the Helsinki University Hospital, the Vasa Hospital District, Turku University Hospital, Vasa Central Hospital, Jakobstadsnejdens Heart Foundation, and the Medical Foundation of Vaasa.

Increased HLA class II risk is associated with a more aggressive presentation of clinical type 1 diabetes

AIM

To determine the association of HLA class II risk with the demographic and clinical characteristics of type 1 diabetes at diagnosis.

METHODS

We conducted a register-based retrospective cohort study of 4993 Finnish children (2169 girls) - diagnosed with type 1 diabetes under the age of 15 years in 2003-2016. The participants were divided into six risk groups based on their HLA DR/DQ genotype. Demographic characteristics, family history of type 1 diabetes and metabolic markers at the time of diagnosis were compared between the groups.

RESULTS

In total, 4056/4993 children (81.2%) carried an HLA genotype associated with an increased risk of type 1 diabetes (risk groups 3-5), whereas 937/4993 children (18.8%) carried a HLA genotype conferring no or decreased disease risk. Children with higher HLA risk were younger at diagnosis (p < 0.001) and had a shorter duration of classical symptoms before diagnosis (p = 0.016). Subjects in the high-risk group were more likely to have a family member affected by type 1 diabetes when compared to those in the neutral risk group (11.5% vs. 8.8%, p = 0.05).

CONCLUSION

Children with stronger HLA disease susceptibility are younger at their disease manifestation and have a shorter period of symptoms before diagnosis, suggesting that the HLA class II genes are associated with a more aggressive disease presentation.

Factors Associated With Diabetic Ketoacidosis at Onset of Type 1 Diabetes Among Pediatric Patients: A Systematic Review

IMPORTANCE

Presenting with diabetic ketoacidosis (DKA) at onset of type 1 diabetes (T1D) remains a risk. Following a 2011 systematic review, considerable additional articles have been published, and the review required updating.

OBJECTIVE

To evaluate factors associated with DKA at the onset of T1D among pediatric patients.

EVIDENCE REVIEW

In this systematic review, PubMed, Embase, Scopus, CINAHL, Web of Science, and article reference lists were searched using the population, intervention, comparison, outcome search strategy for primary research studies on DKA and T1D onset among individuals younger than 18 years that were published from January 2011 to November 2021. These studies were combined with a 2011 systematic review on the same topic. Data were pooled using a random-effects model.

FINDINGS

A total of 2565 articles were identified; 149 were included, along with 46 from the previous review (total 195 articles). Thirty-eight factors were identified and examined for their association with DKA at T1D onset. Factors associated with increased risk of DKA were younger age at T1D onset (<2 years vs ≥2 years; odds ratio [OR], 3.51; 95% CI, 2.85-4.32; P < .001), belonging to an ethnic minority population (OR, 0.40; 95% CI, 0.21-0.74; P = .004), and family history of T1D (OR, 0.46; 95% CI, 0.37-0.57; P < .001), consistent with the 2011 systematic review. Some factors that were not associated with DKA in the 2011 systematic review were associated with DKA in the present review (eg, delayed diagnosis: OR, 2.27; 95% CI, 1.72-3.01; P < .001). Additional factors associated with risk of DKA among patients with new-onset T1D included participation in screening programs (OR, 0.35; 95% CI, 0.21-0.59; P < .001) and presentation during the COVID-19 pandemic (OR, 2.32; 95% CI, 1.76-3.06; P < .001).

CONCLUSIONS AND RELEVANCE

In this study, age younger than 2 years at T1D onset, belonging to an ethnic minority population, delayed diagnosis or misdiagnosis, and presenting during the COVID-19 pandemic were associated with increased risk of DKA. Factors associated with decreased risk of DKA included greater knowledge of key signs or symptoms of DKA, such as a family history of T1D or participation in screening programs. Future work should focus on identifying and implementing strategies related to these factors to reduce risk of DKA among new patients with T1D.

Identification of novel differentially expressed genes in type 1 diabetes mellitus complications using transcriptomic profiling of UAE patients: a multicenter study

Type 1 diabetes mellitus (T1DM) is a chronic metabolic disorder that mainly affects children and young adults. It is associated with debilitating and long-life complications. Therefore, understanding the factors that lead to the onset and development of these complications is crucial. To our knowledge this is the first study that attempts to identify the common differentially expressed genes (DEGs) in T1DM complications using whole transcriptomic profiling in United Arab Emirates (UAE) patients. The present multicenter study was conducted in different hospitals in UAE including University Hospital Sharjah, Dubai Hospital and Rashid Hospital. A total of fifty-eight Emirati participants aged above 18 years and with a BMI < 25 kg/m² were recruited and forty-five of these participants had a confirmed diagnosis of T1DM. Five groups of complications associated with the latter were identified including hyperlipidemia, neuropathy, ketoacidosis, hypothyroidism and polycystic ovary syndrome (PCOS). A comprehensive whole transcriptomic analysis using NGS was conducted. The outcomes of the study revealed the common DEGs between T1DM without complications and T1DM with different complications. The results revealed seven common candidate DEGs, SPINK9, TRDN, PVRL4, MYO3A, PDLIM1, KIAA1614 and GRP were upregulated in T1DM complications with significant increase in expression of SPINK9 (Fold change: 5.28, 3.79, 5.20, 3.79, 5.20) and MYO3A (Fold change: 4.14, 6.11, 2.60, 4.33, 4.49) in hyperlipidemia, neuropathy, ketoacidosis, hypothyroidism and PCOS, respectively. In addition, functional pathways of ion transport, mineral absorption and cytosolic calcium concentration were involved in regulation of candidate upregulated genes related to neuropathy, ketoacidosis and PCOS, respectively. The findings of this study represent a novel reference warranting further studies to shed light on the causative genetic factors that are involved in the onset and development of T1DM complications.

Familial autoimmunity in pediatric patients with type 1 diabetes (T1D) and its associations with the severity of clinical presentation at diabetes diagnosis and with coexisting autoimmunity

PURPOSE

The aim was to evaluate the impact of familial autoimmunity on the age and severity of type 1 diabetes (T1D) presentation and on the coexistence of other autoimmune diseases.

METHODS

We retrospectively evaluated the medical records of 121 children/adolescents (male: 63) followed in our Diabetic Clinic from 2002 to 2016.

RESULTS

Seventy-six patients (62.8%) had at least one relative with an autoimmune disease, Hashimoto's thyroiditis (49.5%) and T1D (22.3%) being the commonest. Children with familial autoimmunity were younger at T1D diagnosis (mean age ± SD) (6.766 ± 3.75). Median fasting c-peptide levels at presentation were not related to familial autoimmunity. Patients with familial autoimmunity more often exhibited GADA autoantibody positivity at diagnosis. The larger the number of the patient's relatives diagnosed with an autoimmune disease, the higher were the patient's GADA levels (Spearman's rho test = 0.19, p = 0.049). Children with a first-degree relative with autoimmunity had a coexisting autoimmune disorder at a significantly higher percentage (p = 0.016). Family history of autoimmunity was negatively associated with the presence of diabetic ketoacidosis (DKA) (p = 0.024). Patients with a relative with T1D less frequently exhibited DKA at diagnosis (12.8 vs. 87.2%, p = 0.003). The presence of DKA was associated with younger age (p = 0.05) and lower c-peptide levels (p = 0.033).

CONCLUSIONS

Familial autoimmunity was present in 62.8% of children with T1D, autoimmune thyroiditis and T1D being the two most frequent familial autoimmune diseases. Familial autoimmunity reduced the risk of DKA at diagnosis, but these patients were younger and had higher levels of pancreatic autoantibodies and a greater risk of developing additional autoimmune diseases.

Heterogeneity in the presentation of clinical type 1 diabetes defined by the level of risk conferred by human leukocyte antigen class II genotypes

OBJECTIVES

The association between human leukocyte antigen (HLA) class II genotypes and susceptibility to type 1 diabetes (T1D) is well established. This study aimed at examining whether there are differences in the presentation of T1D depending on the HLA genotype.

RESEARCH DESIGN AND METHODS

We divided the study participants (N = 5798) in the Finnish Pediatric Diabetes Register into two groups based on the T1D risk conferred by their HLA genotype (high and moderate-risk genotypes, Group 1 vs. other genotypes, Group 2). We then examined differences in clinical, metabolic, and immunological characteristics. Children included in the study were 0-14-year-old and diagnosed between January 2003 and December 2019.

RESULTS

Participants in Group 1 were younger at the time of diagnosis (P < 0.001) and had more frequently family members affected by T1D (P < 0.001). Diabetic ketoacidosis (DKA) was more frequent among participants in Group 2 (P = 0.014) who also had a longer duration of symptoms before diagnosis (P < 0.001) and higher hemoglobin A1c (P = 0.001) at diagnosis. The HLA genotype was not, however, directly related to the DKA frequency. The frequency of islet cell antibodies (P < 0.003), insulin autoantibodies (P < 0.001), and islet antigen 2 autoantibodies (P < 0.001) was higher in Group 1 whereas glutamic acid decarboxylase autoantibodies were more frequent (P < 0.001) in Group 2. Group 1 had more participants with multiple autoantibodies (P = 0.027) whereas antibody negativity was more frequent in Group 2 (P = 0.003).

CONCLUSIONS

These findings indicate disease heterogeneity in relation to both clinical disease presentation and humoral autoimmunity, in particular. This heterogeneity is, at least partly, defined by HLA Class II genotypes.

New-onset type 1 diabetes in Finnish children during the COVID-19 pandemic

BACKGROUND

Viral infections may trigger type 1 diabetes (T1D), and recent reports suggest an increased incidence of paediatric T1D and/or diabetic ketoacidosis (DKA) during the COVID-19 pandemic.

OBJECTIVE

To study whether the number of children admitted to the paediatric intensive care unit (PICU) for DKA due to new-onset T1D increased during the COVID-19 pandemic, and whether SARS-CoV-2 infection plays a role.

METHODS

This retrospective cohort study comprises two datasets: (1) children admitted to PICU due to new-onset T1D and (2) children diagnosed with new-onset T1D and registered to the Finnish Pediatric Diabetes Registry in the Helsinki University Hospital from 1 April to 31 October in 2016-2020. We compared the incidence, number and characteristics of children with newly diagnosed T1D between the prepandemic and pandemic periods.

RESULTS

The number of children admitted to PICU due to new-onset T1D increased from an average of 6.25 admissions in 2016-2019 to 20 admissions in 2020 (incidence rate ratio [IRR] 3.24 [95% CI 1.80 to 5.83]; p=0.0001). On average, 57.75 children were registered to the FPDR in 2016-2019, as compared with 84 in 2020 (IRR 1.45; 95% CI 1.13 to 1.86; p=0.004). 33 of the children diagnosed in 2020 were analysed for SARS-CoV-2 antibodies, and all were negative.

CONCLUSIONS

More children with T1D had severe DKA at diagnosis during the pandemic. This was not a consequence of SARS-CoV-2 infection. Instead, it probably stems from delays in diagnosis following changes in parental behaviour and healthcare accessibility.

Effects of family history of diabetes on pancreatic β-cell function and diabetic ketoacidosis in newly diagnosed patients with type 2 diabetes: a cross-sectional study in China

OBJECTIVE

To investigate the association between a parental and/or sibling history of diabetes and clinical characteristics.

DESIGN

A cross-sectional study.

SETTING

The data were collected from the endocrinology department of The Second Xiangya Hospital of Central South University from June 2017 to October 2019.

PARTICIPANTS

A total of 894 newly diagnosed patients with type 2 diabetes were recruited. Data on clinical characteristics were collected from patient medical records. Pancreatic β-cell function and insulin resistance were calculated with the homeostatic model assessment. SPSS V.25.0 was used to perform the analysis.

RESULTS

The percentages of patients with parental and sibling histories of diabetes were 14.8% and 9.8%, respectively. The prevalence of diabetic ketoacidosis (DKA) was 3.9%. Compared with those with no parental history of diabetes, patients with a parental history of diabetes were characterised by early-onset disease (41.70±10.88 vs 51.17±14.09 years), poor glycaemic control of fasting blood glucose (10.84±5.21 vs 8.91±4.38 mmol/L) and a high prevalence of DKA (7.6% vs 3.3%). The patients with a sibling history of diabetes had later disease onset (56.05±9.86 vs 49.09±14.29 years) and lower BMI (24.49±3.48 vs 25.69±3.86 kg/m²) than those with no sibling history of diabetes. Univariate regression suggested that both parental history (p=0.037) and sibling history (p=0.011) of diabetes were associated with β-cell function; however, multiple regression analysis showed that only a sibling history of diabetes was associated with β-cell function (p=0.038). Univariate regression revealed a positive correlation between parental history of diabetes (p=0.023, OR=2.416, 95% CI 1.132 to 5.156) and DKA. Unfortunately, this correlation was not statistically significant for either patients with a parental history (p=0.234, OR=1.646, 95% CI 0.724 to 3.743) or those with a sibling history (p=0.104, OR=2.319, 95% CI 0.841 to 6.389) after adjustments for confounders.

CONCLUSION

A sibling history of diabetes was associated with poor β-cell function, and a parental history of diabetes was associated with poor glycaemic control and a high prevalence of DKA.

Thyroid peroxidase antibodies are common in children with HLA-conferred susceptibility to type 1 diabetes, but are weakly associated with thyroid function

Background The need for screening for autoimmune thyroid disease in children who have HLA-conferred susceptibility to type 1 diabetes (T1D), but have not yet been diagnosed with T1D, has not been thoroughly studied. The aim of this study was to describe the prevalence of positive thyroid peroxidase antibodies and its effect on thyroid function in children with genetic susceptibility to T1D as well as to describe the association between thyroid autoimmunity and HLA-DQ genotypes. Methods Cross-sectional study in 223 children (112 boys) aged 7.4-10.5 years with HLA-conferred susceptibility to T1D. TPOAb were measured in all children; thyroglobulin antibodies (TGAb) and thyroid function in TPOAb positive subjects. Results Girls had a significantly higher median TPOAb concentration than boys (12 vs 11 kU/L; p=0.001). Positive TPOAb occurred in 13.9% and positive TGAb in 4% of subjects. Only two children had mild changes in thyroid function. There was no association between HLA risk groups and the prevalence of TPOAb. Conclusions TPOAb are common in children with HLA-conferred susceptibility to T1D, yet are weakly associated with thyroid function, suggesting limited value of thyroid screening in this cohort.

Association Between Severity of Diabetic Ketoacidosis at Diagnosis and Multiple Autoimmunity in Children With Type 1 Diabetes Mellitus: A Study From a Greek Tertiary Centre

OBJECTIVES

Type 1 diabetes mellitus is a chronic disorder associated with development of autoimmunity. In this work, we studied the relationship between severity of acidosis at diagnosis and future risk for autoimmunity development in children with type 1 diabetes.

METHODS

We investigated the presence of associated autoimmunity in 144 children with type 1 diabetes (mean ± standard deviation: age, 12.44±4.76 years; diabetes duration, 4.41±3.70 years). We identified the presence of thyroid disease, celiac disease, autoimmune gastritis and adrenal autoimmunity, and retrospectively reviewed the files for presence of diabetic ketoacidosis at diagnosis.

RESULTS

Autoimmunity prevalence was 16.7% for thyroid autoimmunity, 9.5% for celiac disease, 5% for gastric autoimmunity and 8.0% for multiple autoimmunities. There were strong associations between severe acidosis at diabetes diagnosis (pH<7.10) and development of thyroid autoimmunity (odds ratio [OR], 5.34; 95% confidence interval [CI], 1.90‒15.1; p<0.001), celiac disease (OR, 5.83; 95% CI, 1.19‒28.6; p=0.013), gastric autoimmunity (OR, 13.1; 95% CI, 1.22‒140; p=0.006) and multiple autoimmunity (OR, 26.7; 95% CI, 2.36‒301; p<0.01). The associations persisted after adjustment for sex, age at diabetes diagnosis, age at assessment, time since diabetes diagnosis and antiglutamic acid decarboxylase autoantibody status.

CONCLUSIONS

The severity of acidosis at diagnosis is strongly associated with the development of associated autoimmune diseases in children with type 1 diabetes and could act as a predictive factor for multiple autoimmunity development. This association can be either due to effect of acidosis on immune system or to the presence of a more aggressive diabetes endotype.

Characteristics of familial type 1 diabetes: effects of the relationship to the affected family member on phenotype and genotype at diagnosis

AIMS/HYPOTHESIS

In previous studies, the risk of developing familial type 1 diabetes has been reported to be more than two times higher in the offspring of affected fathers than in those of affected mothers. We tested the hypothesis that index children with an affected father may have a more aggressive disease process at diagnosis than those with other affected first-degree relatives.

METHODS

A cross-sectional, observational study was performed using the Finnish Pediatric Diabetes Register. Clinical and metabolic characteristics, beta cell autoantibodies and HLA class II genetics were analysed from index children in Finland diagnosed before the age of 15 years between January 2003 and December 2016. Information on the presence of type 1 diabetes in first-degree relatives was collected at diagnosis using a structured questionnaire.

RESULTS

Out of 4993 newly diagnosed index children, 519 (10.4%) had familial type 1 diabetes. More than 5% (n = 253, 5.1%) had an affected father, 2.8% (n = 141) had an affected mother, 1.9% (n = 95) had an affected sibling and 0.6% (n = 30) had two or more affected family members. All clinical and metabolic variables were markedly poorer in children with sporadic vs familial diabetes. The index children with an affected father or mother were younger than those with an affected sibling (median age 7.59 vs 6.74 vs 10.73 years, respectively; p < 0.001). After age- and sex-adjusted analyses, index children with an affected father presented more often with ketoacidosis (9.7% vs 3.6%; p = 0.033) and had greater weight loss before diagnosis (3.2% vs 0%; p = 0.006) than those with an affected mother. Children with familial disease tested negative for all autoantibodies more often (3.5% vs 2.1%; p = 0.041) and had insulin autoantibodies more frequently (49.8% vs 42.2%; p = 0.004) than those with sporadic disease. Both major HLA risk haplotypes (DR3-DQ2 and DR4-DQ8) were more often lacking among children with sporadic vs familial disease (15.9% vs 11.2%; p = 0.006). The DR4-DQ8 haplotype was more frequent in the familial vs the sporadic group (75.7% vs 68.5%; p = 0.001) and especially among children with an affected father when compared with children with sporadic disease (77.5% vs 68.5%; p < 0.05). When comparing index children with affected parents diagnosed before or after the birth of the index child, a clear male preponderance was seen among the affected parents diagnosed before the birth of the index child (fathers 66.2% vs mothers 33.8%; p = 0.006), whereas the proportion of fathers and mothers was similar if type 1 diabetes was diagnosed after the birth of the index child.

CONCLUSIONS/INTERPRETATION

The more severe metabolic derangement at diagnosis in children with sporadic type 1 diabetes compared with those with familial type 1 diabetes was confirmed. The higher frequency of diabetic ketoacidosis and increased weight loss at diagnosis in index children with an affected father compared with an affected mother support the hypothesis that paternal type 1 diabetes is associated with more severe disease in the offspring than maternal diabetes. The sex difference seen between affected parents diagnosed before and after the birth of the index child supports the hypothesis that maternal insulin treatment protects against type 1 diabetes.

Diabetic ketoacidosis in children newly diagnosed with type 1 diabetes mellitus: Role of demographic, clinical, and biochemical features along with genetic and immunological markers as risk factors. A 20-year experience in a tertiary Belgian center

BACKGROUND

Diabetic ketoacidosis (DKA) is the leading cause of morbidity and mortality in children with type 1 diabetes (T1D). Little is known about the association between genetic and immunological markers and the risk for DKA at onset of T1D. The aim of this study was to create a model foreseeing the onset of DKA in newly diagnosed patients.

METHODS

This retrospective study included 532 T1D children (aged <18 years at diagnosis) recruited in our hospital, from 1995 to 2014. DKA and its severity were defined according to the criteria of ISPAD. Genetic risk categories for developing T1D were defined according to the Belgian Diabetes Registry. Multivariate statistical analyses were applied to investigate risk factors related to DKA at diagnosis.

RESULTS

Overall 42% of patients presented DKA at diagnosis. This study outlined the major risk of DKA at diagnosis for younger children (<3 years) and for those belonging to ethnic minorities. Children carrying neutral genotypes had a 1.5-fold increased risk of DKA at diagnosis than those with susceptible or protective genotypes, a paradoxical observation not previously reported. Only solitary positive IA-2A increased the risk of DKA at diagnosis. The proposed model could help to predict the probability of DKA in 70% of newly diagnosed cases.

CONCLUSIONS

This was the first reported implication of IA-2A positivity and neutral genotypes predisposing to DKA at diagnosis regardless of its severity. Earlier diagnosis through genetic and immunological screening of high-risk children could decrease DKA incidence at diabetes onset.

Ketoacidosis at onset of type 1 diabetes in children up to 14 years of age and the changes over a period of 18 years in Saxony, Eastern-Germany: A population based register study

OBJECTIVE

The aim of this study was to examine the incidence trends of type 1 diabetes diagnosed with ketoacidosis in Saxony, Germany from 1999 to 2016.

METHODS

The population based Childhood Diabetes Registry of Saxony comprising valid data for all children aged 0-14 years diagnosed with type 1 diabetes from1999 to 2016 were used for the analyses. Direct age-standardized incidence rates were calculated and the effects of age, sex, calendar year, home districts and family history of any types of diabetes on the incidence were modelled using Poisson regression. Trend analyses for standard rate ratios of children with moderate and severe diabetic ketoacidosis versus children with type 1 diabetes with non-diabetic ketoacidosis were performed using join point regression.

RESULTS

The rate of ketoacidosis at the time of the type 1 diabetes diagnosis was high with 35.2% during the entire observation period in Saxony. The Poisson regression analysis indicated a statistically significant increased occurrence of diabetic ketoacidosis for younger age-groups, but no statistically significant differences between boys and girls. The join point trend analyses show that the proportion of severe and moderate ketoacidosis is increasing disproportionally to the increase in incidence of type 1 diabetes over the years.

CONCLUSION

Due to the observed increasing incidence of diabetes as well of diabetic ketoacidosis, an educational prevention campaign is needed in Saxony as soon as possible to aid pediatricians, general physicians as well as general public to identify the early signs of type 1 diabetes.

Development of atopic sensitization in Finnish and Estonian children: A latent class analysis in a multicenter cohort

BACKGROUND

The prevalence of atopy is associated with a Western lifestyle, as shown by studies comparing neighboring regions with different socioeconomic backgrounds. Atopy might reflect various conditions differing in their susceptibility to environmental factors.

OBJECTIVE

We sought to define phenotypes of atopic sensitization in early childhood and examine their association with allergic diseases and hereditary background in Finland and Estonia.

METHODS

The analysis included 1603 Finnish and 1657 Estonian children from the DIABIMMUNE multicenter young children cohort. Specific IgE levels were measured at age 3, 4, and 5 years, respectively, and categorized into 3 CAP classes. Latent class analysis was performed with the statistical software package poLCA in R software.

RESULTS

Both populations differed in terms of socioeconomic status and environmental determinants, such as pet ownership, farm-related exposure, time spent playing outdoors, and prevalence of allergic diseases (all P < .001). Nevertheless, we found similar latent classes in both populations: an unsensitized class, a food class, 2 inhalant classes differentiating between seasonal and perennial aeroallergens, and a severe atopy class. The latter was characterized by high total and specific IgE levels and strongly associated with wheeze (odds ratio [OR], 5.64 [95% CI, 3.07-10.52] and 4.56 [95% CI, 2.35-8.52]), allergic rhinitis (OR, 22.4 [95% CI, 11.67-44.54] and 13.97 [95% CI, 7.33-26.4]), and atopic eczema (OR, 9.39 [95% CI, 4.9-19.3] and 9.5 [95% CI, 5.2-17.5] for Finland and Estonia, respectively). Environmental differences were reflected in the larger seasonal inhalant atopy class in Finland, although composition of classes was comparable between countries.

CONCLUSION

Despite profound differences in environmental exposures, there might exist genuine patterns of atopic sensitization. The distribution of these patterns might determine the contribution of atopic sensitization to disease onset.

Ketoacidosis at diagnosis of type 1 diabetes: Effect of prospective studies with newborn genetic screening and follow up of risk children

We studied the frequency of diabetic ketoacidosis (DKA) in children at diagnosis of type 1 diabetes (T1D) in a region where newborn infants have since 1995 been recruited for genetic screening for human leukocyte antigen (HLA)-conferred disease susceptibility and prospective follow up. The aim was to study whether participation in newborn screening and follow up affected the frequency of DKA, and to follow the time trends in DKA frequency. We first included children born in Oulu University Hospital since 1995 when the prospective studies have been ongoing and diagnosed with T1D <15 years by 2015 (study cohort 1, n = 517). Secondly, we included all children diagnosed with T1D <15 years in this center during 2002-2014 (study cohort 2, n = 579). Children who had an increased genetic risk for T1D and participated in prospective follow up had low frequency of DKA at diagnosis (5.0%). DKA was present in 22.7% of patients not screened for genetic risk, 26.7% of those who were screened but had not an increased risk and 23.4% of children with increased genetic risk but who were not followed up. In study cohort 2 the overall frequency of DKA was 18.5% (13.0% in children <5 years, 14.0% in children 5-10 years and 28.6% in children ≥10 years at diagnosis; P<.001). In children <2 years the frequency of DKA was 17.1%. Participation in prospective follow-up studies reduces the frequency of DKA in children at diagnosis of T1D, but genetic screening alone does not decrease DKA risk.

Characteristics of the pre-diabetic period in children with high risk of type 1 diabetes recruited from the general Swedish population-The ABIS study

BACKGROUND

There is a need for increased understanding of the pre-diabetic period in individuals with high risk of type 1 diabetes from the general population.

METHODS

High-risk children (n = 21) positive for multiple islet autoantibodies were identified by autoantibody screening within the All Babies in Southeast Sweden study. The children and their parents were enrolled in a 2-year prospective follow-up study aiming to characterize the pre-diabetic period. Blood samples were collected every 6 months for measurement of C-peptide, HbA1c, fasting glucose, and autoantibodies. Human leukocyte antigen-genotype was determined, and oral glucose tolerance test was performed every 12 months.

RESULTS

Despite positivity for multiple autoantibodies, 9 out of 21 individuals had low-risk human leukocyte antigen-genotypes. Children who progressed to manifest diabetes (progressors, n = 12) had higher levels of IA2A and ZnT8A than children who did not (non-progressors, n = 9). Impaired glucose tolerance and impaired fasting glucose was observed to the same extent in progressors and non-progressors, but HbA1c increased over time in progressors in spite of increased C-peptide.

CONCLUSIONS

Autoantibodies to IA2 and ZnT8 may be useful discriminators for disease progression in at-risk children from the general population. Dysglycemia was observed long before diagnosis, and difficulties in maintaining glucose homeostasis despite increased C-peptide indicate that insulin resistance might be an important accelerator of disease in risk individuals.

Genetic susceptibility to type 1 diabetes in childhood - estimation of HLA class II associated disease risk and class II effect in various phases of islet autoimmunity

OBJECTIVE

The HLA-DR/DQ region remains the major determinant of susceptibility to type 1 diabetes (T1D) despite the more than 50 risk affecting loci outside human leukocyte antigen (HLA) region that have been identified. We aimed at developing a simple risk estimation based on HLA class II genotyping, which was also tested by analyzing HLA class II effect on the autoantibody seroconversion and further progression to diabetes.

SUBJECTS AND METHODS

A total of 2991 trio families with a diabetic child from the Finnish Pediatric Diabetes Register were genotyped and the risk contributed by each DR-DQ haplotype calculated through transmission analysis. The genotype risk was estimated based on the summary effect of haplotypes. Genotype grouping was further tested in a subcohort of the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) Study

RESULTS

The summary effect of haplotypes was generally seen in genotypes, while the expected synergistic effect of DR3-DQ2 and DR4-DQ8 (DRB1*04:03 excluded) combination was also clear in the T1D risk association analysis. This highest risk DR/DQ genotype was found in 21.6% of patients and 2.0% of controls, odds ratio (OR) = 13.2 (10.1-17.2), whereas the lowest risk genotype contained only 0.8% of patients and 28.0% of controls, OR = 0.02 (0.01-0.03). In the subcohort from the DIPP study the risk grades correlated clearly with seroconversion for islet autoantibodies and T1D development. In contrast, DR/DQ risk groups did not associate with the progression rate from advanced autoimmunity to clinical diabetes.

CONCLUSIONS

Class II HLA genotype groups improve the estimation of T1D risk. Class II effect is limited to the early phase of the disease process characterized by seroconversion for islet autoantibodies.

Epidemiology of diabetic ketoacidosis in Arab patients with type 1 diabetes: a systematic review

AIMS

Diabetic ketoacidosis (DKA) is an acute and risky complication of type 1 diabetes. The aim of this study is to build the overall rate of DKA in Arab patients with type 1 diabetes in the 22 Arab nations. This is expected to tailor the healthcare approaches in Arab countries where attention is needed to save lives from the devastating consequences of DKA.

METHODS

The study here is a quantitative analysis of the articles indexed in four different scientific literature databases: Web of Science, PubMed, Science Direct and Scopus, from inception to June 2015. Arab patients with type 1 diabetes who presented with DKA have been captured. Key information was possible to extract for patients belong to only 12 Arab countries out of the 22 Arab patients.

RESULTS

Twenty-nine studies in 12 different Arab countries captured 4,688 type 1 diabetes patients with overall rates of 46.7% patients presented with DKA, ranging from a low of 17% in Egypt to a high of 100% in Morocco, Algeria and Tunisia.

CONCLUSION

This is the first descriptive quantitative study to determine the overall DKA rate in 46 years of studies in the Arab world of patients with type 1 diabetes; DKA rates were found to range from 17% to 100% with overall rate of 46.7%.

Increased Blood Levels of Growth Factors, Proinflammatory Cytokines, and Th17 Cytokines in Patients with Newly Diagnosed Type 1 Diabetes

The production of several cytokines could be dysregulated in type 1 diabetes (T1D). In particular, the activation of T helper (Th) type 1 (Th1) cells has been proposed to underlie the autoimmune pathogenesis of the disease, although roles for inflammatory processes and the Th17 pathway have also been shown. Nevertheless, despite evidence for the role of cytokines before and at the onset of T1D, the corresponding findings are inconsistent across studies. Moreover, conflicting data exist regarding the blood cytokine levels in T1D patients. The current study was performed to investigate genetic and autoantibody markers in association with the peripheral blood cytokine profiles by xMap multiplex technology in newly diagnosed young T1D patients and age-matched healthy controls. The onset of young-age T1D was characterized by the upregulation of growth factors, including granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin (IL)-7, the proinflammatory cytokine IL-1β (but not IL-6 or tumor necrosis factor [TNF]-α), Th17 cytokines, and the regulatory cytokines IL-10 and IL-27. Ketoacidosis and autoantibodies (anti-IA-2 and -ZnT8), but not human leukocyte antigen (HLA) genotype, influenced the blood cytokine levels. These findings broaden the current understanding of the dysregulation of systemic levels of several key cytokines at the young-age onset of T1D and provide a further basis for the development of novel immunoregulatory treatments in this disease.

Differences in B7 and CD28 family gene expression in the peripheral blood between newly diagnosed young-onset and adult-onset type 1 diabetes patients

Type-1 diabetes (T1D) is a heterogeneous autoimmune disease, and there are pathogenetic differences between young- and adult-onset T1D patients. We hypothesized that the expressions of genes involved in costimulatory immune system pathways in peripheral blood are differently regulated in young- and adult-onset T1D. Study group I consisted of 80 children, adolescents, and young adults (age range 1.4-21.4 y; 31 controls and 49 T1D patients). Study group II consisted of 48 adults (age range 22.0-78.4 y; 30 controls and 18 T1D patients). The mRNA expression levels of CD86, CD28, CD25, CD226, CD40, BTLA, GITR, PDCD1, FoxP3, TGF-β, ICOS, sCTLA4, flCTLA4, and CD80 were measured in peripheral blood. Genetic polymorphisms (HLA haplotypes; rs231806, rs231775, and rs3087243 in CTLA4; rs763361 in CD226; and rs706778 in CD25) and T1D-associated autoantibodies were analyzed. In group I, there was significantly lower expression of CD226 in T1D patients than in the controls. In group II, there were significantly higher expression levels of CD86 and TGF-β in T1D patients than in the controls. In the T1D patients in group I, the upregulated CD80 expression correlated with the expression of both CTLA4 splice variants (sCTLA4 and flCTLA4). In contrast, in group II, upregulated CD86 correlated with TGF-β and CD25. In group I, the inhibitory CD80-CTLA4 pathway was activated, whereas, in group II, the activation CD86-CD28 pathway and TGF-β production were activated. These results emphasize the differences between young-onset and adult-onset T1D in the regulation of costimulatory pathways. These differences should be considered when developing novel treatments for T1D.

OGTT and random plasma glucose in the prediction of type 1 diabetes and time to diagnosis

AIMS/HYPOTHESIS

We assessed the utility of the OGTT and random plasma glucose concentrations in predicting the time to diagnosis of type 1 diabetes.

METHODS

A population-derived cohort of 14,876 newborns with HLA-conferred risk of type 1 diabetes were invited to regular follow-up for islet autoantibodies. When two or more autoantibodies were detected, an OGTT was performed once a year and random plasma glucose analysed twice a year. During follow-up, 567 children developed multiple autoantibodies, 255 (45%) of whom were diagnosed with type 1 diabetes, while 312 remained non-diabetic by December 2011.

RESULTS

Impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) were risk factors for type 1 diabetes (HR 3.2 [95% CI 1.5, 7.0] and 8.3 [95% CI 6.0, 11.5], respectively). When a random plasma glucose value ≥ 7.8 mmol/l was observed, the HR for diabetes was 6.0 (95% CI 4.3, 8.6). The median time to diagnosis after the detection of IFG was 5.2 years (interquartile range [IQR] 3.4, 6.3); after IGT, 0.7 years (IQR 0.3, 1.9); and, after a random plasma glucose ≥ 7.8 mmol/l, 1.0 years (IQR 0.3, 1.5). In a retrospective analysis, both OGTT-derived 2 h plasma glucose and random plasma glucose started to increase 1.5 years before diagnosis (p < 0.001 and p = 0.004, respectively).

CONCLUSIONS/INTERPRETATION

Dysglycaemia detected in an OGTT or based on random plasma glucose is a useful marker in the prediction of time to onset of type 1 diabetes in high-risk children. Random plasma glucose is a simple and low-cost measurement with comparable predictive characteristics to that of OGTT-derived 2 h glucose.

Circulating IGF1 and IGFBP3 in relation to the development of β-cell autoimmunity in young children

OBJECTIVE

This study aimed at investigating the role of IGF1 and IGF binding protein 3 (IGFBP3) in the development of β-cell autoimmunity.

METHODS

Five hundred and sixty-three subjects with HLA-conferred susceptibility to type 1 diabetes (T1D) were monitored for signs of seroconversion to positivity for insulin and/or GAD, IA2, and zinc transporter 8 autoantibodies by the age of 3 years. In 40 subjects who developed at least one autoantibody, IGF1 and IGFBP3 plasma concentrations were measured and compared with 80 control subjects who remained negative for autoantibodies, and were matched for age, sex, country of origin, and HLA genotype. The increments of IGF1, IGFBP3, and IGF1/IGFBP3 molar ratio before and after seroconverison were compared with corresponding time intervals in controls.

RESULTS

The IGF1 concentrations at the age of 12 months and the IGF1/IGFBP3 ratio at the age of 24 months were lower in the autoantibody-positive children (P<0.05). The increase in circulating IGFBP3 was significantly higher in the autoantibody-positive children before seroconversion than in the corresponding time intervals in controls (0.43 mg/l; 95% CI 0.29-0.56 vs 0.22 mg/l; 95% CI 0.10-0.34 mg/l; P<0.01). Children carrying the high-risk HLA genotype had lower plasma IGF1 and IGFBP3 concentrations at the age of 24 months than those with low-risk genotypes (P<0.05 and < 0.01 respectively).

CONCLUSIONS

Circulating IGF1 and IGFBP3 appear to have a role in early development of β-cell autoimmunity. The decreased IGF1 concentrations in children with the high-risk HLA genotype may contribute to the reduced growth previously described in such children.

Non-HLA gene effects on the disease process of type 1 diabetes: From HLA susceptibility to overt disease

In addition to the HLA region numerous other gene loci have shown association with type 1 diabetes. How these polymorphisms exert their function has not been comprehensively described, however. We assessed the effect of 39 single nucleotide polymorphisms (SNP) on the development of autoantibody positivity, on progression from autoantibody positivity to clinical disease and on the specificity of the antibody initiating the autoimmune process in 521 autoantibody-positive and 989 control children from a follow-up study starting from birth. Interestingly, PTPN2 rs45450798 gene polymorphism was observed to strongly affect the progression rate of beta-cell destruction after the appearance of humoral beta-cell autoimmunity. Moreover, primary autoantigen dependent associations were also observed as effect of the IKZF4-ERBB3 region on the progression rate of β-cell destruction was restricted to children with GAD antibodies as their first autoantibody whereas the effect of the INS rs 689 polymorphism was observed among subjects with insulin as the primary autoantigen. In the whole study cohort, INS rs689, PTPN22 rs2476601 and IFIH1 rs1990760 polymorphisms were associated with the appearance of beta-cell autoantibodies. These findings provide new insights into the role of genetic factors implicated in the pathogenesis of type 1 diabetes. The effect of some of the gene variants is restricted to control the initiation of β-cell autoimmunity whereas others modify the destruction rate of the β-cells. Furthermore, signs of primary autoantigen-related pathways were detected.

HbA1c Predicts Time to Diagnosis of Type 1 Diabetes in Children at Risk

Prediction of type 1 diabetes is based on the detection of multiple islet autoantibodies in subjects who are at increased genetic risk. Prediction of the timing of diagnosis is challenging, however. We assessed the utility of HbA1c levels in predicting the clinical disease in genetically predisposed children with multiple autoantibodies. Cord blood samples from 168,055 newborn infants were screened for class II HLA genotypes in Finland, and 14,876 children with increased genetic risk for type 1 diabetes were invited to participate in regular follow-ups, including screening for diabetes-associated autoantibodies. When two or more autoantibodies were detected, HbA1c levels were analyzed at each visit. During follow-up, multiple (two or more) autoantibodies developed in 466 children; type 1 diabetes was diagnosed in 201 of these children (43%, progressors), while 265 children remained disease free (nonprogressors) by December 2011. A 10% increase in HbA1c levels in samples obtained 3-12 months apart predicted the diagnosis of clinical disease (hazard ratio [HR] 5.7 [95% CI 4.1-7.9]) after a median time of 1.1 years (interquartile range [IQR] 0.6-3.1 years) from the observed rise of HbA1c. If the HbA1c level was ≥5.9% (41 mmol/mol) in two consecutive samples, the median time to diagnosis was 0.9 years (IQR 0.3-1.5, HR 11.9 [95% CI 8.8-16.0]). In conclusion, HbA1c is a useful biochemical marker when predicting the time to diagnosis of type 1 diabetes in children with multiple autoantibodies.

Age-associated DNA methylation changes in immune genes, histone modifiers and chromatin remodeling factors within 5 years after birth in human blood leukocytes

Background

Age-related changes in DNA methylation occurring in blood leukocytes during early childhood may reflect epigenetic maturation. We hypothesized that some of these changes involve gene networks of critical relevance in leukocyte biology and conducted a prospective study to elucidate the dynamics of DNA methylation. Serial blood samples were collected at 3, 6, 12, 24, 36, 48 and 60 months after birth in ten healthy girls born in Finland and participating in the Type 1 Diabetes Prediction and Prevention Study. DNA methylation was measured using the HumanMethylation450 BeadChip.

Results

After filtering for the presence of polymorphisms and cell-lineage-specific signatures, 794 CpG sites showed significant DNA methylation differences as a function of age in all children (41.6% age-methylated and 58.4% age-demethylated, Bonferroni-corrected P value <0.01). Age-methylated CpGs were more frequently located in gene bodies and within +5 to +50 kilobases (kb) of transcription start sites (TSS) and enriched in developmental, neuronal and plasma membrane genes. Age-demethylated CpGs were associated to promoters and DNAse-I hypersensitivity sites, located within −5 to +5 kb of the nearest TSS and enriched in genes related to immunity, antigen presentation, the polycomb-group protein complex and cytoplasm.

Conclusions

This study reveals that susceptibility loci for complex inflammatory diseases (for example, IRF5, NOD2, and PTGER4) and genes encoding histone modifiers and chromatin remodeling factors (for example, HDAC4, KDM2A, KDM2B, JARID2, ARID3A, and SMARCD3) undergo DNA methylation changes in leukocytes during early childhood. These results open new perspectives to understand leukocyte maturation and provide a catalogue of CpG sites that may need to be corrected for age effects when performing DNA methylation studies in children.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-015-0064-6) contains supplementary material, which is available to authorized users.

Th1/Th17 plasticity is a marker of advanced β cell autoimmunity and impaired glucose tolerance in humans

Upregulation of IL-17 immunity and detrimental effects of IL-17 on human islets have been implicated in human type 1 diabetes. In animal models, the plasticity of Th1/Th17 cells contributes to the development of autoimmune diabetes. In this study, we demonstrate that the upregulation of the IL-17 pathway and Th1/Th17 plasticity in peripheral blood are markers of advanced β cell autoimmunity and impaired β cell function in human type 1 diabetes. Activated Th17 immunity was observed in the late stage of preclinical diabetes in children with β cell autoimmunity and impaired glucose tolerance, but not in children with early β cell autoimmunity. We found an increased ratio of IFN-γ/IL-17 expression in Th17 cells in children with advanced β cell autoimmunity, which correlated with HbA1c and plasma glucose concentrations in an oral glucose tolerance test, and thus impaired β cell function. Low expression of Helios was seen in Th17 cells, suggesting that Th1/Th17 cells are not converted thymus-derived regulatory T cells. Our results suggest that the development of Th1/Th17 plasticity may serve as a biomarker of disease progression from β cell autoantibody positivity to type 1 diabetes. These data in human type 1 diabetes emphasize the role of Th1/Th17 plasticity as a potential contributor to tissue destruction in autoimmune conditions.

Interferon and interferon-inducible gene activation in patients with type 1 diabetes

Type 1 diabetes (T1D) is an autoimmune disease that is thought to be triggered by environmental factors in genetically susceptible individuals. Enteroviruses have been mentioned as the most probable induction component of the disease. Nevertheless, the literature is controversial regarding the association of T1D with viral infection and first-line antiviral defence components, for example type I interferons (IFNs). Our aim was to test the hypothesis that an abnormality in IFN-stimulated gene patterns may cause a failure in immunological tolerance and, thereby, initiate T1D as an autoimmune disorder. We studied material from 64 T1D and 36 control subjects, divided into two age groups: <10 years and ≥10 years old. Using a relative gene expression method, we observed a lower expression of interferon-induced helicase 1 (IFIH1) and other type I IFN-induced genes in the blood cells of T1D subjects, especially subjects under 10 years old, in spite of their higher IFN levels as measured by the pSTAT1-inducing capacity of their sera. Likewise, freshly purified CpG-stimulated cells from T1D patients showed significantly lower upregulation of IFN-induced genes, that is IFIH1 and CXCL10, compared to cells from the control group. The identified dysregulation in the IFN-α-induced antiviral response in T1D patients, especially in early childhood, could be one of the factors affecting T1D development.

Diabetic ketoacidosis at diagnosis in Austrian children: a population-based analysis, 1989-2011

OBJECTIVE

To analyze the effect of a community-based, poster-focused prevention program on the frequency of diabetic ketoacidosis (DKA) at diabetes onset in Austria.

STUDY DESIGN

All newly diagnosed patients with diabetes ≤ 15 years of age were registered prospectively by the Austrian Diabetes Incidence Study Group. Registered data included initial blood glucose, pH, and ketonuria. DKA was defined as pH < 7.3 and severe DKA as pH < 7.1. Data between 1989 and 2011 were available. In autumn, 2009, a community-based prevention program similar to the Parma Campaign, in which posters were dispensed broadly, was initiated. The frequency of DKA at the onset of diabetes in the years 2005-2009 and 2010-2011 was compared.

RESULTS

During the study period, 4038 children were registered. A total of 37.2% presented with DKA; 26% had a mild and 11.2% a severe form. The frequency of DKA was negatively associated with age at onset. In the years before the intervention program, 26% had mild DKA compared with 27% after the intervention (not significant). The prevalence of severe DKA in the years before the campaign was 12% compared with 9.5% thereafter (not significant). No significant change in the DKA rate at onset by the prevention program could be found when we compared age groups <5, 5 to <10, and 10 to <15 years, neither for mild nor for severe DKA.

CONCLUSION

The frequency of DKA in children with newly diagnosed type 1 diabetes in Austria is high and did not change despite the efforts of a community-based information program.

Insulin secretion and sensitivity in the prediction of type 1 diabetes in children with advanced β-cell autoimmunity

OBJECTIVE

Reduced early insulin response has been shown to predict type 1 diabetes (T1D) in first-degree relatives of diabetic patients, while its role, as well as that of insulin resistance, has remained poorly defined in young children representing the general population. The predictive values of these markers and their relation to other risk factors of T1D were assessed in children with advanced β-cell autoimmunity, i.e. persistent positivity for two or more autoantibodies.

DESIGN AND METHODS

Intravenous glucose tolerance tests (IVGTTs) were carried out in 218 children with HLA-DQB1-conferred disease susceptibility and advanced β-cell autoimmunity. Baseline, metabolic and growth data were compared between children progressing to diabetes and those remaining unaffected. Hazard ratios for the disease predictors and the progression rate of T1D were assessed.

RESULTS

Children developing T1D were younger at seroconversion, progressed more rapidly to advanced β-cell autoimmunity and had lower first-phase insulin response (FPIR) and homeostasis model assessment index for insulin resistance (HOMA-IR) than those remaining non-diabetic. The levels of HOMA-IR/FPIR, islet cell antibodies, insulin autoantibodies (IAA) and islet antigen 2 antibodies (IA-2A) were higher in progressors. BMI SDS, FPIR, age at IVGTT and levels of IAA and IA-2A were predictive markers for T1D.

CONCLUSIONS

Young age, higher BMI SDS, reduced FPIR and higher levels of IAA and IA-2A predicted T1D in young children with HLA-DQB1-conferred disease susceptibility and advanced β-cell autoimmunity. Disease risk estimates were successfully stratified by the assessment of metabolic status and BMI. The role of insulin resistance as an accelerator of the disease process was minor.

Diabetic ketoacidosis at diagnosis: role of family history and class II HLA genotypes

OBJECTIVE

To explore the relationship between family history of diabetes and frequency of diabetic ketoacidosis (DKA) at diagnosis and to analyze the possible association between HLA genotypes and DKA.

DESIGN AND METHODS

We recruited 510 children and adolescents aged <17 years with type 1 diabetes (T1D) and collected information on first-degree relative (FDR) history of T1D. DKA and severe DKA were defined as blood pH <7.30 and <7.10 at diabetes onset respectively. Risk categories for developing T1D were determined according to various HLA DQA1-DQB1 haplotype combination genotypes.

RESULTS

The frequency of DKA and severe DKA at diagnosis was 34.7 and 7.2% respectively. DKA was more frequent in younger patients (<2 years (60.0%; P<0.001)) and occurred less in children with at least one FDR affected by T1D (13.0 vs 37.4%, P<0.001). The logistic regression showed that age at diagnosis (<2 years) and increased HLA-associated risk genotypes were independent predictors of DKA (P<0.01, odds ratio (OR)=1.068 (95% confidence interval (CI) 1.021-1.117); P<0.05, OR=1.606 (95% CI 1.034-2.475)). Introducing the presence of T1D in at least one FDR in the logistic model, a significant association between DKA and age at diagnosis (<2 years; P<0.01, OR=1.072 (95% CI 1.024-1.123)) and absence of FDRs with T1D (P=0.001, OR=4.287 (95% CI 1.770-10.383)) was found, but no more with increased HLA-associated risk genotype (P=0.06, OR=1.550 (95% CI 0.992-2.423)).

CONCLUSIONS

HLA-associated high-risk genotypes are associated with a high chance of presenting DKA at diabetes onset. However, having at least one FDR with T1D reduced the risk of DKA regardless of HLA genotype.