Variation and trends in incidence of childhood diabetes in Europe. EURODIAB ACE Study Group

Cardiovascular Risk in Children and Adolescents with Type 1 and Type 2 Diabetes Mellitus

Rising rates of both type 1 and type 2 diabetes mellitus in children have led to increased concern regarding cardiovascular disease (CVD) risk during childhood. Diabetic children face prolonged exposure to hyperglycemia, and have increased risk of both microvascular and macrovascular disease. These circumstances may result in a generation of young adults presenting with cardiovascular outcomes, a tremendous personal and public health toll. In this article, we review CVD risk in type 1 and type 2 diabetes, discuss aspects of pathophysiology, and review current methods of CVD risk assessment. We also identify crucial areas in need of future research in order to devise effective prevention and treatment of CVD risk in children.

Incidence and modes of presentation of childhood type 1 diabetes mellitus in Malta between 2006 and 2010

AIM

To assess the incidence and mode of presentation of type 1 diabetes mellitus (T1DM) in children and adolescents younger than 14 yr of age between January 2006 and December 2010 in Malta.

METHODS

A nationwide prospective study which collected data from newly diagnosed T1DM children who presented to the only paediatric diabetes team available in Malta. The degree of ascertainment was estimated to be 100%. Incidence rates by age group and year were estimated using real values of diagnosed patients and population statistics. Trend analysis was carried out using Poisson's regression analysis.

RESULTS

From 2006 to 2010, 81 children below the age of 14 yr were diagnosed with T1DM for the first time. The age- and sex-standardised incidence rate was 21.86/100,000 children/yr. The estimated annual increase in incidence was 21.8%. Compared to data collected retrospectively between 1996-2001, the incidence has increased threefold between 2006 and 2010. Generally, the incidence rate was highest in the 5-9 yr age group, followed by the 0-4 yr age group and finally the10-14 yr age group. However, the highest annual increase occurred in the 0-4 yr age group at 39% per year, closely followed by 5-9 yr age group at 31% per year. In the 10-14 yr age group, the trend appeared to show a reduction in incidence. The proportion of patients presenting in diabetic ketoacidosis (DKA) was high at 41%.

CONCLUSION

In Malta, the number of children/adolescents with T1DM has been rising at a faster rate than expected, and a distinct shift to younger age at onset has been observed. DKA rate at presentation is still high in Maltese children.

Type 1 diabetes onset and pandemic influenza A (H1N1)

Type 1 diabetes (T1D) is a heterogeneous disorder characterized by destruction of pancreatic beta cells, culminating in loss of insulin secretion. Data from large epidemiologic studies worldwide indicate that during the last decades the incidence of T1D has increased significantly, reaching percentages of 2-5% annually. This increase suggests that there is a significant environmental contribution impacting the development of the disease, since genetic factors alone can hardly explain the rapid increase. Studies regarding T1D epidemiology in diverse populations aim to identify the disease causal factors and new targets for intervention. Viruses are one of the environmental factors implicated in the development of T1D in susceptible individuals. Recent studies suggest an association of T1D with H1N1 influenza. We would like to comment on this association and report our experience. Prospective studies are necessary to assess whether H1N1 infection is involved in T1D pathogenesis and provide directions on how to deal with viral infections in diabetes-susceptible individuals.

Pediatric diabetic ketoacidosis management in the era of standardization

Up to 70% of children with new-onset Type 1 diabetes mellitus (T1DM) present with diabetic ketoacidosis (DKA), with most cases initially assessed by their primary care provider. DKA is the most common cause of death in children with T1DM, mainly related to cerebral edema that occurs at a frequency of 0.15-4.6%. Early recognition of DKA can be improved by increasing the awareness of early clinical symptoms such as enuresis, polyuria and polydipsia. Clinical acumen paired with early assessment of patients with suspected T1DM and known T1DM, particularly if risk factors for DKA are present, can prevent serious complications and fatal outcomes. Urgent referral to specialist centers for suspected new-onset T1DM/DKA is required. A standardized approach is recommended to be followed to ensure successful initial management of DKA, both in the nonspecialist setting before transfer and in the more specialized hospital setting. This article outlines such a management approach.

Prevalence of adults with type 1 diabetes who meet the goals of care in daily clinical practice: a nationwide multicenter study in Brazil

OBJECTIVE

To determine the prevalence of patients with type 1 diabetes mellitus who meet the glycemic and cardiovascular (CV) risk factors goals and the frequency of screening for diabetic complications in Brazil according to the American Diabetes Association guidelines.

RESEARCH DESIGN AND METHODS

This was a cross-sectional, multicenter study conducted between December 2008 and December 2010 in 28 public clinics in 20 Brazilian cities. Data were obtained from 1774 adult patients (56.8% females, 57.2% Caucasians) aged 30.3 ± 9.8 years with diabetes duration of 14.3 ± 8.8 years.

RESULTS

Systolic blood pressure was at goal in 40.3% and diastolic blood pressure was at goal in 26.6% of hypertensive patients. LDL cholesterol and HbA1c were at the goal in 45.2% and 13.2% of the patients, respectively. Overweight was presented in 25.6% and obesity in 6.9%. Among those with more than 5 years of disease, screening for retinopathy was performed in the preceding year in 70.1%. Nephropathy and feet complications were screened in 63.1% and 65.1%, respectively.

CONCLUSIONS

The majority of patients did not meet metabolic control goals and a substantial proportion was not screened for diabetic complications. These issues may increase the risk of chronic complications and negatively impact public health.

Application of the capture-recapture method in estimating the size of the active homosexual male population in Hangzhou city of China

The homosexual population is particularly susceptible to sexually transmitted disease because of various high-risk sexual behaviors among them. The authors explored the application of capture-recapture methods in estimating the size of the sexually active homosexual male population in Hangzhou. Homosexual men at 9 activity sites were investigated in Hangzhou, Zhejiang. The total active homosexual male population of Hangzhou estimated by the capture-recapture method and multiplier method was 2014 (95% confidence interval [CI] = 1899-2129) and 2012.5 (95% CI 1925 to 2101), respectively. This study shows that the capture-recapture method can be used to enumerate and provide accurate and reliable estimates of the active homosexual population in any area, provided that certain conditions are controlled.

Type 1 diabetes and measles, mumps and rubella childhood infections within the Italian Insulin-dependent Diabetes Registry

AIMS

Several studies confirmed the growing rate of Type 1 diabetes mellitus in childhood coinciding with increasing diagnosis of viral infections. A study investigating the incidence of Type 1 diabetes during 1996-1997 showed a higher notification of viral infections in the Pavia District. The aim was to confirm these results.

METHODS

This study evaluated the relationship between new cases of Type 1 diabetes and those of measles, mumps and rubella in 1996-2001, analysing data of newly-diagnosed Type 1 diabetes children, aged 0-14 years and enrolled into the RIDI (Italian Insulin-dependent Diabetes Registry) during the same years. Measles, rubella and mumps rates were calculated using as denominator the estimated 'population at risk', represented by the number of 0- to 14 year-old subjects who did not undergo the MMR (measles, mumps and rubella) vaccination. In order to investigate the association between Type 1 diabetes incidence and measles, rubella and mumps respectively, Spearman's rank correlation was used.

RESULTS

The analysis of the whole Registries data did not at first show any statistical significance between age-standardized Type 1 diabetes incidence density and estimated rates of measles, mumps and rubella notifications. Excluding data from Sardinia Registry, a significant association was observed between Type 1 diabetes incidence and mumps (P = 0.034) and rubella (P = 0.014), respectively, while there was no statistical significance between the incidence of measles cases and diabetes rates (P = 0.269).

CONCLUSIONS

According to our findings, mumps and rubella viral infections are associated with the onset of Type 1 diabetes. The statistical significance observed after exclusion of the Sardinian data suggests that other environmental factors may operate over populations with different genetic susceptibility.

Immunology in the clinic review series: focus on type 1 diabetes and viruses: the role of viruses in type 1 diabetes: a difficult dilemma

Convincing evidence now indicates that viruses are associated with type 1 diabetes (T1D) development and progression. Human enteroviruses (HEV) have emerged as prime suspects, based on detection frequencies around clinical onset in patients and their ability to rapidly hyperglycaemia trigger in the non-obese diabetic (NOD) mouse. Whether or not HEV can truly cause islet autoimmunity or, rather, act by accelerating ongoing insulitis remains a matter of debate. In view of the disease's globally rising incidence it is hypothesized that improved hygiene standards may reduce the immune system's ability to appropriately respond to viral infections. Arguments in favour of and against viral infections as major aetiological factors in T1D will be discussed in conjunction with potential pathological scenarios. More profound insights into the intricate relationship between viruses and their autoimmunity-prone host may lead ultimately to opportunities for early intervention through immune modulation or vaccination.

Creating a national register of childhood type 1 diabetes using routinely collected hospital data

INTRODUCTION

There is no national register of childhood type 1 diabetes mellitus for England. Our aim was to assess the feasibility of using routine hospital admissions data as a surrogate for a childhood diabetes register across England, and to create a geographically referenced childhood diabetes dataset for use in epidemiologic studies and health service research.

METHODS

Hospital Episodes Statistics data for England from April 1992 to March 2006 referring to a type 1 diabetes diagnosis in 0-14 yr olds were cleaned to approximate an incident dataset. The cleaned data were validated against regional population-based register data, available for Yorkshire and the area of the former Oxford Regional Health Authority.

RESULTS

There were 32 665 unique cases of type 1 and type unknown diabetes over the study period. The hospital-derived data improved in quality over time (91% concordance with regional register data over the period 2000-2006 vs. 52% concordance over the period 1992-1999), and data quality was better for younger (0-9 yr) (86.5% concordance with regional register data) than older cases (10-14 yr). Overall incidence was 24.99 (95% confidence interval 24.71-25.26) per 100 000. Basic trends in age distribution, seasonality of onset, and incidence matched well with previously reported findings.

CONCLUSION

We were able to create a surrogate register of childhood diabetes based on national hospital admissions data, containing approximately 2300 cases/yr, and geo-coded to a high resolution. For younger cases (0-9 yr) and more recent years (from 2000) these data will be a useful resource for epidemiological studies exploring the determinants of childhood diabetes.

Could the social environment trigger the induction of diabetes related autoantibodies in young children?

AIMS

The onset and progression of the autoimmune process leading to type 1 diabetes is partly dependent on genetic predisposition and partly on environmental factors. We have implemented a study design where 1-year-old children, from two equally sized, neighbouring but socioeconomically different cities, were compared for the induction of beta-cell autoantibodies.

METHODS

This study comprises 2448 newborn infants, all living in the urban parts of the twin cities, followed prospectively with regular biological samples and questionnaires in a major population-based study. Of these, a random sample of 1497 children were tested for tyrosine phosphatase (IA-2A) and 1409 children for glutamic acid decarboxylase (GADA). Other documented risk factors of beta-cell autoimmunity and type 1 diabetes, such as family characteristics, dietary factors, and psychosocial factors were also included in the analysis.

RESULTS

The risk for diabetes-related autoantibodies, both against GADA and IA-2A (>95% cut off), was significantly higher (p<0.0001) among children from the blue-collar than from the white-collar city. This difference persisted still after adjustment for other previously documented risk factors. Some of these previously known risk factors remained significant in the multivariate analysis as independent explanatory factors, in addition to living in a blue-collar city.

CONCLUSIONS

Factors in the social environment could trigger the induction of diabetes-related autoantibodies in 1-year-old children. These results point out that our present knowledge of factors influencing the autoimmune process might be widen to also include factors in the social environment of the community.

Genetically engineered islets and alternative sources of insulin-producing cells for treating autoimmune diabetes: quo vadis?

Islet transplantation is a promising therapy for patients with type 1 diabetes that can provide moment-to-moment metabolic control of glucose and allow them to achieve insulin independence. However, two major problems need to be overcome: (1) detrimental immune responses, including inflammation induced by the islet isolation/transplantation procedure, recurrence autoimmunity, and allorejection, can cause graft loss and (2) inadequate numbers of organ donors. Several gene therapy approaches and pharmaceutical treatments have been demonstrated to prolong the survival of pancreatic islet grafts in animal models; however, the clinical applications need to be investigated further. In addition, for an alternative source of pancreatic β-cell replacement therapy, the ex vivo generation of insulin-secreting cells from diverse origins of stem/progenitor cells has become an attractive option in regenerative medicine. This paper focuses on the genetic manipulation of islets during transplantation therapy and summarizes current strategies to obtain functional insulin-secreting cells from stem/progenitor cells.

How does age at onset influence the outcome of autoimmune diseases?

The age at onset refers to the time period at which an individual experiences the first symptoms of a disease. In autoimmune diseases (ADs), these symptoms can be subtle but are very relevant for diagnosis. They can appear during childhood, adulthood or late in life and may vary depending on the age at onset. Variables like mortality and morbidity and the role of genes will be reviewed with a focus on the major autoimmune disorders, namely, systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), multiple sclerosis (MS), type 1 diabetes mellitus (T1D), Sjögren's syndrome, and autoimmune thyroiditis (AITD). Early age at onset is a worst prognostic factor for some ADs (i.e., SLE and T1D), while for others it does not have a significant influence on the course of disease (i.e., SS) or no unanimous consensus exists (i.e., RA and MS).

Genome-wide association studies (GWAS): impact on elucidating the aetiology of diabetes

It has proven to be challenging to isolate the genes underlying the genetic components conferring susceptibility to type 1 and type 2 diabetes. Unlike previous approaches, 'genome-wide association studies' have extensively delivered on the promise of uncovering genetic determinants of complex diseases, with a number of novel disease-associated variants being largely replicated by independent groups. This review provides an overview of these recent breakthroughs in the context of type 1 and type 2 diabetes, and outlines strategies on how these findings will be applied to impact clinical care for these two highly prevalent disorders.

A genome-wide meta-analysis of six type 1 diabetes cohorts identifies multiple associated loci

Diabetes impacts approximately 200 million people worldwide, of whom approximately 10% are affected by type 1 diabetes (T1D). The application of genome-wide association studies (GWAS) has robustly revealed dozens of genetic contributors to the pathogenesis of T1D, with the most recent meta-analysis identifying in excess of 40 loci. To identify additional genetic loci for T1D susceptibility, we examined associations in the largest meta-analysis to date between the disease and ∼2.54 million SNPs in a combined cohort of 9,934 cases and 16,956 controls. Targeted follow-up of 53 SNPs in 1,120 affected trios uncovered three new loci associated with T1D that reached genome-wide significance. The most significantly associated SNP (rs539514, P = 5.66×10⁻¹¹) resides in an intronic region of the LMO7 (LIM domain only 7) gene on 13q22. The second most significantly associated SNP (rs478222, P = 3.50×10⁻⁹) resides in an intronic region of the EFR3B (protein EFR3 homolog B) gene on 2p23; however, the region of linkage disequilibrium is approximately 800 kb and harbors additional multiple genes, including NCOA1, C2orf79, CENPO, ADCY3, DNAJC27, POMC, and DNMT3A. The third most significantly associated SNP (rs924043, P = 8.06×10⁻⁹) lies in an intergenic region on 6q27, where the region of association is approximately 900 kb and harbors multiple genes including WDR27, C6orf120, PHF10, TCTE3, C6orf208, LOC154449, DLL1, FAM120B, PSMB1, TBP, and PCD2. These latest associated regions add to the growing repertoire of gene networks predisposing to T1D.

Despite the fact that there is clearly a large genetic component to type 1 diabetes (T1D), uncovering the genes contributing to this disease has proven challenging. However, in the past three years there has been relatively major progress in this regard, with advances in genetic screening technologies allowing investigators to scan the genome for variants conferring risk for disease without prior hypotheses. Such genome-wide association studies have revealed multiple regions of the genome to be robustly and consistently associated with T1D. More recent findings have been a consequence of combining of multiple datasets from independent investigators in meta-analyses, which have more power to pick up additional variants contributing to the trait. In the current study, we describe the largest meta-analysis of T1D genome-wide genotyped datasets to date, which combines six large studies. As a consequence, we have uncovered three new signals residing at the chromosomal locations 13q22, 2p23, and 6q27, which went on to be replicated in independent sample sets. These latest associated regions add to the growing repertoire of gene networks predisposing to T1D.

Selective IgA deficiency in autoimmune diseases

Selective immunoglobulin A deficiency (IgAD) is the most common primary immunodeficiency in Caucasians. It has previously been suggested to be associated with a variety of concomitant autoimmune diseases. In this review, we present data on the prevalence of IgAD in patients with Graves disease (GD), systemic lupus erythematosus (SLE), type 1 diabetes (T1D), celiac disease (CD), myasthenia gravis (MG) and rheumatoid arthritis (RA) on the basis of both our own recent large-scale screening results and literature data. Genetic factors are important for the development of both IgAD and various autoimmune disorders, including GD, SLE, T1D, CD, MG and RA, and a strong association with the major histocompatibility complex (MHC) region has been reported. In addition, non-MHC genes, such as interferon-induced helicase 1 (IFIH1) and c-type lectin domain family 16, member A (CLEC16A), are also associated with the development of IgAD and some of the above diseases. This indicates a possible common genetic background. In this review, we present suggestive evidence for a shared genetic predisposition between these disorders.

The ALBA project: an evaluation of needs, management, fears of Italian young patients with type 1 diabetes in a school setting and an evaluation of parents' and teachers' perceptions

OBJECTIVE

To determine how Italian parents and school personnel of 6-13-year-old children with type 1 diabetes (T1D) manage during school hours, including insulin administration, management of hypoglycemia, and glucagon use. A further aim was an investigation into the responsibilities and training of school personnel regarding diabetes.

RESEARCH DESIGN AND METHODS

After an initial qualitative phase, semi-structured questionnaires were completed by a sample of parents and teachers.

RESULTS

220 parent and 52 teacher questionnaires were completed. 43.6% of parents said diabetes had negatively influenced school activities. Children either self-administer insulin, or have help from a parent, since there is very rarely a nurse present (3.6%) or a teacher who will take responsibility for the treatment (2.9%). Most parents (55.9%) stated either that the school had no refrigerator to store glucagon or that they did not know if the school was so equipped. A small percentage of teachers considered their schools to be equipped to manage an emergency (23%) and said they would use glucagon directly in an emergency (14.9%). Only 40.4% of teachers said that they had received any specific training.

CONCLUSIONS

The study shows that people who are not directly involved have superficial knowledge of the different aspects of diabetes, even though no parents reported episodes of neglect/incorrect management. There is no legislation which clearly defines the role of the school in the care of children with T1D, and teachers are not trained to help them. Training sessions for school personnel and greater legislative clarity about the 'insulin and glucagon question' are key factors that may improve the full integration of the child with diabetes.

Under-recognition and reporting of dengue in Cambodia: a capture–recapture analysis of the National Dengue Surveillance System

Robust disease burden estimates are important for decision-making concerning introduction of new vaccines. Dengue is a major public health problem in the tropics but robust disease burden estimates are lacking. We conducted a two-sample, capture–recapture study in the largest province in Cambodia to determine disease under-recognition to the National Dengue Surveillance System (NDSS). During 2006–2008, community-based active surveillance for acute febrile illness was conducted in 0- to 19-year-olds in rural and urban areas combined with testing for dengue virus infection. Of 14 354 individuals under active surveillance (22 498 person-seasons), the annual incidence ranged from 13·4 to 57·8/1000 person-seasons. During the same period, NDSS incidence rates ranged from 1·1/1000 to 5·7/1000, which was 3·9- to 29·0-fold lower than found in the capture–recapture study. In hospitalized cases, the rate of under-recognition was 1·1- to 2·4-fold. This study shows the substantial degree of under-recognition/reporting of dengue and that reported hospitalized cases are not a good surrogate for estimating dengue disease burden.

Data standards in diabetes patient registries

Widespread adoption of electronic health records (EHRs) and expansion of patient registries present opportunities to improve patient care and population health and advance translational research. However, optimal integration of patient registries with EHR functions and aggregation of regional registries to support national or global analyses will require the use of standards. Currently, there are no standards for patient registries and no content standards for health care data collection or clinical research, including diabetes research. Data standards can facilitate new registry development by supporting reuse of well-defined data elements and data collection systems, and they can enable data aggregation for future research and discovery. This article introduces standardization topics relevant to diabetes patient registries, addresses issues related to the quality and use of registries and their integration with primary EHR data collection systems, and proposes strategies for implementation of data standards in diabetes research and management.

Protection against or triggering of Type 1 diabetes? Different roles for viral infections

The emergence of autoreactivity that ultimately destroys insulin-producing β-cells and causes Type 1 diabetes (T1D) is a result of genetic susceptibility and environmental factors, such as viral infections. The ability to induce strong cellular immune responses and to cause inflammation in the target organ makes viral infections prime candidates for the initiation of islet autoreactivity. Indeed, certain viruses have been linked to the occurrence of T1D based on epidemiological, serological and histological findings; and several rodent studies clearly demonstrate that viral infections can trigger autoimmunity. However, viruses have also been shown to efficiently prevent autoimmunity, which underlines the beneficial aspects of exposure to microbial agents as suggested by the hygiene hypothesis. Here, we will try to untangle some aspects of the complex interplay between viruses and the immune system and we will recapitulate by what rationale certain viruses have been associated with T1D.

Prediction and prevention of Type 1 diabetes mellitus

Type 1A diabetes mellitus (T1DM) is caused by autoimmune islet β-cell destruction with consequent severe insulin deficiency. We can now predict the development of T1DM by determining four biochemically characterized islet autoantibodies, namely those antibodies against insulin, glutamic acid decarboxylase 65, insulinoma antigen (IA)-2 (ICA512) and the zinc transporter ZnT8. We can also prevent T1DM in animal models, but the final goal is the prevention of T1DM in humans. Multiple clinical trials are underway investigating methods to prevent β-cell destruction.

Parent stress and child behaviour among young children with type 1 diabetes

BACKGROUND

Parents of young children with type 1 diabetes (T1D) are responsible for executing a complex daily management regimen and are at risk for elevated levels of stress. Normative misbehaviour during the preschool years can complicate T1D management, and interpretation of behavioural concerns may vary because of child health status and parent stress. Within a paediatric transactional model framework, child characteristics (e.g. behaviour problems, metabolic control) and parent functioning (e.g. parenting stress, anxiety) likely impact one another.

METHODS

Parents of 2- to 6-year-old children with T1D completed self-report measures, including the Pediatric Inventory for Parents (PIP), State-Trait Anxiety Inventory (STAI), Eyberg Child Behavior Inventory (ECBI), and 24-h Recall Interviews. Medical data were obtained by parent report and medical record review. It was hypothesized that greater parent stress and child blood glucose variability would be significantly associated with greater parent-reported child behaviour concerns.

RESULTS

Moderate levels of parent stress and child behaviour problems were endorsed; however, parents perceived children's misbehaviour as problematic, particularly with relation to tasks relevant to diabetes management (e.g. bedtimes and mealtimes). Structural equation modelling indicated that greater general anxiety and paediatric parenting stress was associated with parent report of more problematic child behaviour. Blood glucose variability did not significantly contribute to this relationship.

CONCLUSIONS

The stress experienced by parents of young children with chronic illness appears to relate to their perception of their children's behaviour problems. Parents' experiences with developmentally normative misbehaviour may interfere with disease management and exacerbate parents' stress and the subsequent impact on well-being. Implications for supporting parents and children with T1D are discussed.

Association of insulin sensitivity to lipids across the lifespan in people with Type 1 diabetes

AIMS

Insulin resistance and dyslipidaemia both increase cardiovascular risk in Type 1 diabetes. However, little data exist on the associations of insulin resistance to lipids in Type 1 diabetes. Our objective was to explore the associations between insulin resistance (assessed by glucose infusion rate) and lipids in people with Type 1 diabetes and determine whether adiposity and/or average glycaemia influence these associations.

METHODS

Hyperinsulinaemic-euglycaemic clamp studies were performed in 60 subjects with Type 1 diabetes aged 12-19 years (age 15±2 years, 57% female, duration of diabetes 6.3±3.8 years, HbA(1c) 8.6±1.5%, IFCC=70 mmol/mol) and 40 subjects with Type 1 diabetes aged 27-61 years (age 45±9 years, 53% female, duration of diabetes 23±8 years, HbA(1c) 7.5±0.9%, IFCC=58 mmol/mol). Multiple linear regression models were fit to examine the association between glucose infusion rate and fasting lipid levels with adjustment for possible confounders.

RESULTS

Lower glucose infusion rate was significantly associated with lower levels of HDL cholesterol in youths with Type 1 diabetes and with higher levels of triglycerides and higher triglyceride/HDL ratio in both youths and adults. The magnitude of the associations between glucose infusion rate and lipid levels translate into interquartile differences of 0.098 mmol/l for HDL cholesterol, 0.17 mmol/l for triglycerides and 1.06 for triglycerides/HDL in the adolescents and 0.20 mmol/l for triglycerides and 1.01 for triglycerides/HDL in the adults. The associations were attenuated and no longer statistically significant by adjustment for adiposity among adults, while adjustment for HbA(1c) had a small effect in youths and adults.

CONCLUSIONS

Lower insulin sensitivity is associated with a more atherogenic lipid profile in both youths and adults with Type 1 diabetes.

The changing epidemiology of type 1 diabetes: why is it going through the roof?

The incidence of type 1 diabetes is increasing and this may double the burden of disease in our youngest by 2020. The recent increase in incidence is mostly happening in the very young and those with moderate genetic susceptibility. Many environmental factors have been implicated, but no major determinants have been clearly identified, and the mechanisms of involvement remain elusive. This review summarizes current research efforts directed at understanding the possible reasons for this increase, including the role of viruses, gut microbiota, early life feeding patterns, perinatal factors and childhood growth patterns. It also provides a road map for future research directions.

Diabetes in young--unusual case presentation

Diabetes in young is increasing in prevalence with each decade. Phenotypic features like obesity and acanthosis nigricans characterize type 2 diabetes, whereas autoimmune diseases like vitiligo and hypothyroidism suggest type 1 diabetes. We recently encountered a young boy with vitiligo who presented with hyperglycemia, but not associated with ketonuria and has underlying chronic pancreatitis with secondary diabetes. We report the case for its unusual presentation and etiology of the diabetes.

Encephalopathies: the emerging diabetic complications

Diabetic encephalopathies are now accepted complications of diabetes. They appear to differ in type 1 and type 2 diabetes as to underlying mechanisms and the nature of resulting cognitive deficits. The increased incidence of Alzheimer's disease in type 2 diabetes is associated with insulin resistance, hyperinsulinemia and hyperglycemia, and commonly accompanying attributes such as hypercholesterolemia, hypertension and obesity. The relevance of these disorders as to the emergence of dementia and Alzheimer's disease is discussed based on epidemiological studies. The pathobiology of accumulation of β-amyloid and tau the hallmarks of Alzheimer's disease are discussed based on experimental data. Type 1 diabetic encephalopathy is likely to increase as a result of the global increase in the incidence of type 1 diabetes and its occurrence in increasingly younger patients. Alzheimer-like changes and dementia are not prominently increased in type 1 diabetes. Instead, the type 1 diabetic encephalopathy involves learning abilities, intelligence development and memory retrieval resulting in impaired school and professional performances. The major underlying component here appears to be insulin deficiency with downstream effects on the expression of neurotrophic factors, neurotransmitters, oxidative and apoptotic stressors resulting in defects in neuronal integrity, connectivity and loss commonly occurring in the still developing brain. Recent experimental data emphasize the role of impaired central insulin action and provide information as to potential therapies. Therefore, the underlying mechanisms resulting in diabetic encephalopathies are complex and appear to differ between the two types of diabetes. Major headway has been made in our understanding of their pathobiology; however, many questions remain to be clarified. In view of the increasing incidence of both type 1 and type 2 diabetes, intensified investigations are called for to expand our understanding of these complications and to find therapeutic means by which these disastrous consequences can be prevented and modified.

Dietary iron intake in the first 4 months of infancy and the development of type 1 diabetes: a pilot study

AIMS

To investigate the impact of iron intake on the development of type 1 diabetes (T1DM).

METHODS

Case-control study with self-administered questionnaire among families of children with T1DM who were less than 10 years old at the time of the survey and developed diabetes between age 1 and 6 years. Data on the types of infant feeding in the first 4 months of life was collected from parents of children with T1DM (n = 128) and controls (n = 67) <10 years old. Because some cases had sibling controls, we used conditional logistic regression models to analyze the data in two ways. First we performed a case-control analysis of all 128 cases and 67 controls. Next, we performed a case-control analysis restricted to cases (n = 59) that had a sibling without diabetes (n = 59). Total iron intake was modeled as one standard deviation (SD) increase in iron intake. The SD for iron intake was 540 mg in the total sample and 539 mg in the restricted sample as defined above.

RESULTS

The median (min, max) total iron intake in the first 4 months of life was 1159 (50, 2399) mg in T1DM cases and 466 (50, 1224) mg among controls (P < 0.001). For each one standard deviation increase in iron intake, the odds ratio (95% confidence interval) for type 1 diabetes was 2.01 (1.183, 3.41) among all participants (128 cases and 67 controls) while it was 2.26 (1.27, 4.03) in a restricted sample of T1 D cases with a control sibling (59 cases and 59 controls) in models adjusted for birth weight, age at the time of the survey, and birth order.

CONCLUSION

In this pilot study, high iron intake in the first 4 months of infancy is associated with T1DM. Whether iron intake is causal or a marker of another risk factor warrants further investigation.

Epidemiology of type 1 diabetes

This article describes the epidemiology of type 1 diabetes mellitus (T1D) around the world and across the lifespan. Epidemiologic patterns of T1D by demographic, geographic, biologic, cultural, and other factors in populations are presented to gain insight about the causes, natural history, risks, and complications of T1D. Data from large epidemiologic studies worldwide indicate that the incidence of T1D has been increasing by 2% to 5% worldwide and that the prevalence of T1D is approximately 1 in 300 in the United States by 18 years of age. Research on risk factors for T1D is an active area of research to identify genetic and environmental triggers that could potentially be targeted for intervention. Although significant advances have been made in the clinical care of T1D with resultant improvements in quality of life and clinical outcomes, much more needs to be done to improve care of, and ultimately find a cure for, T1D. Epidemiologic studies have an important ongoing role to investigate the complex causes, clinical care, prevention, and cure of T1D.

A nested case-control study of intrauterine exposure to persistent organochlorine pollutants in relation to risk of type 1 diabetes

BACKGROUND

The incidence of type 1 diabetes in Europe is increasing at a rate of about 3% per year and there is also an increasing incidence throughout the world. Type 1 diabetes is a complex disease caused by multiple genetic and environmental factors. Persistent organochlorine pollutants (POPs) have been suggested as a triggering factor for developing childhood type 1 diabetes. The aim of this case-control study was to assess possible impacts of in utero exposure to POPs on type 1 diabetes.

METHODOLOGY/ PRINCIPAL FINDINGS

The study was performed as a case-control study within a biobank in Malmö, a city located in the Southern part of Sweden. The study included 150 cases (children who had their diagnosis mostly before 18 years of age) and 150 controls, matched for gender and day of birth. 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153) and the major DDT metabolite 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE) were used as a biomarkers for POP exposure. When comparing the quartile with the highest maternal serum concentrations of PCB-153 with the other quartiles, an odds ratio (OR) of 0.73 (95% confidence interval [CI] 0.42, 1.27) was obtained. Similar results was obtained for p,p'-DDE (OR 0.56, 95% CI 0.29, 1.08).

CONCLUSIONS

The hypothesis that in utero exposure to POPs will trigger the risk for developing type 1 diabetes was not supported by the results. The risk estimates did, although not statistically significant, go in the opposite direction. However, it is not reasonable to believe that exposure to POPs should protect against type 1 diabetes.

Asthma and autoimmunity: a complex but intriguing relation

Asthma and autoimmune diseases apparently have little to share except for the involvement of the immune system in both types of disorder. However, epidemiological studies have shown that asthma and Type 1 diabetes, a typical autoimmune disease, are associated at the population level, and some experimental findings have suggested that autoimmune mechanisms might be operating in asthma as well. Female preponderance, increased incidence of antinuclear autoantibodies and detection of autoantibodies against either bronchial epithelial antigens or endothelial antigens in patients with nonallergic asthma suggest that the disease may have an autoimmune basis. Approximately 50% of patients with nonallergic asthma react to intradermal injection of autologous serum, indicating the presence of circulating vasoactive factors and suggesting an autoreactive mechanism. Recent findings in experimental animals support the involvement of an autoreactive mechanism in allergic asthma as well, indicating that human alpha-nascent polypeptide-associated complex, identified as an IgE-reactive autoantigen, has the potential to sensitize and induce immediate skin reactions and airway inflammation. In summary, asthma is a heterogeneous disorder characterized by chronic inflammation of the respiratory airways that can be triggered by allergen exposure or by other mechanisms, possibly autoreactive/autoimmune. The autoimmune hypothesis is further, indirectly, supported by the response to immunosuppressive drugs.

The inhibitory effect against collagen-induced arthritis by Schistosoma japonicum infection is infection stage-dependent

BACKGROUND

A long-term existing schistosome infection can aid in maintaining immuno-homeostasis, thus providing protection against various types of autoimmune diseases to the infected host. Such benefits have often been associated with acute or egg stage infection and with the egg-induced Th2 response. However, since schistosome infection undergoes different stages, each associated with a specific induction of Th responses, the requirements for the ability of the different stages of schistosome infection to protect against autoimmune disease has not been elucidated. The present study was designed to study whether different stages of schistosome infection offer unique protection in collagen-induced arthritis and its mechanisms.

RESULTS

Arthritis susceptible strain DBA/1 male mice were infected with Schistosoma japonicum for either 2 weeks resulting in early stage infection or for 7 weeks resulting in acute or egg stage infection. Following Schistosoma japonicum infection, collagen II was administered to induce collagen-induced arthritis, an animal model for human rheumatoid arthritis. Infection by Schistosoma japonicum significantly reduced the severity and the incidence of experimental autoimmune collagen-induced arthritis. However, this beneficial effect can only be provided by a pre-established acute stage of infection but not by a pre-established early stage of the infection. The protection against collagen-induced arthritis correlated with reduced levels of anti-collagen II IgG, especially the subclass of IgG2a. Moreover, in protected mice increased levels of IL-4 were present at the time of collagen II injection together with sustained higher IL-4 levels during the course of arthritis development. In contrast, in unprotected mice minimal levels of IL-4 were present at the initial stage of collagen II challenge together with lack of IL-4 induction following Schistosoma japonicum infection.

CONCLUSION

The protective effect against collagen-induced arthritis provided by Schistosoma japonicum infection is infection stage-dependent. Furthermore, the ability of schistosomiasis to negatively regulate the onset of collagen-induced arthritis is associated with a dominant as well as long-lasting Th2 response at the initiation and development of autoimmune joint and systemic inflammation.

Prevention of diabetes in NOD mice by repeated exposures to a contact allergen inducing a sub-clinical dermatitis

BACKGROUND

Type 1 diabetes is an autoimmune disease, while allergic contact dermatitis although immune mediated, is considered an exposure driven disease that develops due to epicutaneous contact with reactive low-molecular chemicals. The objective of the present study was to experimentally study the effect of contact allergens on the development of diabetes in NOD mice. As the link between contact allergy and diabetes is yet unexplained we also examined the effect of provocation with allergens on Natural Killer T (NKT) cells, since involvement of NKT cells could suggest an innate connection between the two diseases.

METHOD

NOD mice 4 weeks of age were exposed, on the ears, to two allergens, p-phenylenediamine and 2,4-dinitrochlorobenzene respectively, to investigate the diabetes development. The mice were followed for a maximum of 32 weeks, and they were either repeatedly exposed to the allergens or only sensitized a week after arrival. The stimulation of NKT cells by the two allergens were additionally studied in C57BL/6 mice. The mice were sensitized and two weeks later provocated with the allergens. The mice were subsequently euthanized at different time points after the provocation.

RESULTS

It was found that repeated application of p-phenylenediamine reduced the incidence of diabetes compared to application with water (47% vs. 93%, P = 0.004). Moreover it was shown that in C57BL/6 mice both allergens resulted in a slight increment in the quantity of NKT cells in the liver. Application of the allergens at the same time resulted in an increased number of NKT cells in the draining auricular lymph node, and the increase appeared to be somewhat allergen specific as the accumulation was stronger for p-phenylenediamine.

CONCLUSION

The study showed that repeated topical application on the ears with a contact allergen could prevent the development of diabetes in NOD mice. The contact allergens gave a non-visible, sub-clinical dermatitis on the application site. The preventive effect on diabetes may be due to stimulation of peripheral NKT cells, as shown for provocation with p-phenylenediamine in the C57BL/6 mouse. This epicutaneous procedure may lead to new strategies in prevention of type 1 diabetes in humans.

Can the genetics of type 1 and type 2 diabetes shed light on the genetics of latent autoimmune diabetes in adults?

The pathophysiology of latent autoimmune diabetes in adults (LADA) is considered less understood than its much better characterized counterparts of type 1 and type 2 diabetes (T1D and T2D), where its clinical presentation exhibits some features of each of these two main diseases, earning it a reputation as being "type 1.5 diabetes". The etiology of LADA remains unknown, but a genetic component has been implicated from recent reports of T1D and T2D genes playing a role in its pathogenesis. One way to shed much needed light on the classification of LADA is to determine the discrete genetic factors conferring risk to the pathogenesis of this specific phenotype and to determine to what extent LADA shares genetic similarities with T1D and T2D. For instance, no conclusive support for a role of the T1D-associated INS gene has been reported in T2D; conversely, but similarly, no evidence has been found for the role of the T2D-associated genes IDE/HHEX, SLC30A8, CDKAL1, CDKN2A/B, IGF2BP2, FTO, and TCF7L2 in T1D. However, and somewhat at odds with current thinking, TCF7L2, the most strongly associated gene with T2D to date, is strongly associated with LADA, a disorder considered by the World Health Organization to be a slowly progressing form of T1D. In this review, we address recent advances in the genetics of T1D and T2D and how such discoveries have in turn shed some light on the genetics of LADA as being potentially at the "genetic intersection" of these two major diseases.

Prevalence of type 1 diabetes mellitus in Karnal district, Haryana state, India

BACKGROUND

Little work has been done on the prevalence of type 1 diabetes in north India. This paper reports the prevalence of type 1 diabetes in Karnal district of Haryana state, India.

MATERIALS AND METHODS

Prevalence of type 1 diabetes was assessed by a hospital-based registry and by analysis of data contributed by chemists and other physicians.

RESULTS

The overall prevalence of type 1 diabetes in Karnal district is 10.20/100,000 population, with a higher prevalence in urban (26.6/100,000) as compared to rural areas (4.27/100,000). Karnal city, with a population of 222017, has a relatively high prevalence of type 1 diabetes (31.9/100,000). The prevalence in men is higher (11.56/100,000) than in women (8.6/100,000).In the 5 to 16 years age group, the prevalence is 22.22/100,000, while in the 0-5 years age group, prevalence is 3.82/100,000.

CONCLUSIONS

This report highlights the urban-rural and male-female gradient in the prevalence of type 1 diabetes in Karnal, north India.

A study of three polymorphic sites of the ADA gene in children with type 1 diabetes mellitus

BACKGROUND

Adenosine deaminase is a polymorphic enzyme that has an important role in immune functions and in the regulation of intracellular and extracellular concentrations of adenosine and adenosine receptor activity.

AIM

To search for possible association of type 1 diabetes mellitus (DM1) with three loci haplotypes (ADA1, ADA2, ADA6) of the adenosine deaminase gene.

PATIENTS

One hundred and eighty-nine consecutive children with DM1 from Sassari, Sardinia, and a control sample of 239 children from the same area were studied.

METHODS

ADA loci genotypes were determined by DNA analysis.

RESULTS

Compared to controls, diabetic boys show a decrease of the 2(2)/6(1) haplotype while diabetic girls show an increase of the same haplotype. This association was replicated in an independent sample from Continental Italy.

CONCLUSIONS

The 2(2)/6(1) haplotype may exert a protective action in males but may increase susceptibility to DM1 in females: OR = 0.398, 95% CI 0.16-0.96 for males, and OR = 2.31, 95% CI 1.32-4.06 for females.

Validation of a health administrative data algorithm for assessing the epidemiology of diabetes in Canadian children

OBJECTIVE

To validate a case definition of pediatric diabetes using administrative health data and describe trends in incidence and prevalence over time in Ontario, Canada.

METHODS

We sampled hospital records of 700 children from 1994 to 2003 with a prior history of at least one outpatient or hospital record for diabetes mellitus and 300 randomly selected children with no diabetes records. We defined patients as having diabetes based on diagnoses and drug utilization from chart abstraction and compared sensitivity and specificity of a number of combinations of overall health care use using administrative data to develop a highly specific definition. We used Poisson regression to test changes in incidence over time (1994-2003).

RESULTS

Use of four physician claims and no hospital records over a 2-yr period yielded the most specific definition (83% sensitivity, 99% specificity). Using this definition overall age/sex standardized incidence per 100,000 was 32.3 [95% confidence intervals (CI) 30.4, 34.4] and prevalence 241.5 per 100 000 (95% CI 236.2-249.9) in 2003/2004. Overall incidence differs by age, (peaking in 10-14 yr olds) but not significantly by sex. The overall incidence has increased on average by 3.1% per year since 1994 (95% CI 1.02-1.04), with no difference in the rate of increase by age.

CONCLUSIONS

Population-based surveillance of diabetes in children is possible using administrative data. This will facilitate further study of trends in incidence but also in use of health services and outcomes. Further work to differentiate type 1 and 2 diabetes will be important.

Manual closed-loop insulin delivery in children and adolescents with type 1 diabetes: a phase 2 randomised crossover trial

BACKGROUND

Closed-loop systems link continuous glucose measurements to insulin delivery. We aimed to establish whether closed-loop insulin delivery could control overnight blood glucose in young people.

METHODS

We undertook three randomised crossover studies in 19 patients aged 5-18 years with type 1 diabetes of duration 6.4 years (SD 4.0). We compared standard continuous subcutaneous insulin infusion and closed-loop delivery (n=13; APCam01); closed-loop delivery after rapidly and slowly absorbed meals (n=7; APCam02); and closed-loop delivery and standard treatment after exercise (n=10; APCam03). Allocation was by computer-generated random code. Participants were masked to plasma and sensor glucose. In APCam01, investigators were masked to plasma glucose. During closed-loop nights, glucose measurements were fed every 15 min into a control algorithm calculating rate of insulin infusion, and a nurse adjusted the insulin pump. During control nights, patients' standard pump settings were applied. Primary outcomes were time for which plasma glucose concentration was 3.91-8.00 mmol/L or 3.90 mmol/L or lower. Analysis was per protocol. This trial is registered, number ISRCTN18155883.

FINDINGS

17 patients were studied for 33 closed-loop and 21 continuous infusion nights. Primary outcomes did not differ significantly between treatment groups in APCam01 (12 analysed; target range, median 52% [IQR 43-83] closed loop vs 39% [15-51] standard treatment, p=0.06;

INTERPRETATION

Closed-loop systems could reduce risk of nocturnal hypoglycaemia in children and adolescents with type 1 diabetes.

FUNDING

Juvenile Diabetes Research Foundation; European Foundation for Study of Diabetes; Medical Research Council Centre for Obesity and Related Metabolic Diseases; National Institute for Health Research Cambridge Biomedical Research Centre.

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Key Words Collapse

MESH Headings

• Adolescent
• Algorithms
• Biosensing Techniques
• Blood Glucose/metabolism
• Child
• Child, Preschool
• Cross-Over Studies
• Diabetes Mellitus, Type 1/blood
• Diabetes Mellitus, Type 1/drug therapy
• Female
• Humans
• Hypoglycemic Agents/administration & dosage
• Infusions, Subcutaneous
• Insulin/administration & dosage
• Insulin/blood
• Insulin Infusion Systems
• Male
• Treatment Outcome

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Grants

• G0600717 Medical Research Council

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Affiliation(s)

Roman Hovorka Department of Paediatrics, University of Cambridge, Cambridge, UK.
Janet M Allen
Daniela Elleri
Ludovic J Chassin
Julie Harris
Dongyuan Xing
Craig Kollman
Tomas Hovorka
Anne Mette F Larsen
Marianna Nodale
Alessandra De Palma
Malgorzata E Wilinska
Carlo L Acerini
David B Dunger

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Advances in urinary proteome analysis and biomarker discovery in pediatric renal disease

Recent progress in proteomic analysis and strategies for the identification of clinically useful biomarkers in biofluids has led to the identification of urine as an excellent non-invasive reservoir for biomarkers of disease. Urinary biomarkers have been identified and validated on independent cohorts in different high-incidence adult renal diseases, including diabetic nephropathy, chronic kidney disease and immunoglobulin A-nephropathy, but also in extrarenal disease, such as coronary artery disease. Unfortunately, this type of research is underrepresented in the pediatric population. Here, we present the rare studies in the pediatric population that identified potential clinically useful urinary biomarkers in ureteropelvic junction (UPJ) obstruction and renal Fanconi syndrome. These studies, although limited in number, clearly show the potential of urinary proteomics, especially in the pediatric population. It is anticipated that the advances made in the adult population, the lessons learned on the use of appropriate statistics and the inclusion of independent blinded validation cohorts in these types of studies will rapidly lead to clinical useful urinary biomarkers for other pediatric (renal) disease in a population where non-invasive analysis is particularly appreciated.

Toll-like receptors and type 1 diabetes

Type 1 diabetes (T1D) is an autoimmune disease that results in the progressive loss of insulin producing cells. Studies performed in humans with T1D and animal models of the disease over the past two decades have suggested a key role for the adaptive immune system in disease mechanisms. The role of the innate immune system in triggering T1D was shown only recently. Research in this area was greatly facilitated by the discovery of toll-like receptors (TLRs) that were found to be a key component of the innate immune system that detect microbial infections and initiate antimicrobial host defense responses. New data indicate that in some situations, the innate immune system is associated with mechanisms triggering autoimmune diabetes. In fact, studies preformed in the BioBreeding Diabetes Resistant (BBDR) and LEW1.WR1 rat models of T1D demonstrate that virus infection leads to islet destruction via mechanisms that may involve TLR9-induced innate immune system activation. Data from these studies also show that TLR upregulation can synergize with virus infection to dramatically increase disease penetrance. Reports from murine models of T1D implicate both MyD88-dependent and MyD88-independent pathways in the course of disease. The new knowledge about the role of innate immune pathways in triggering islet destruction could lead to the discovery of new molecules that may be targeted for disease prevention.

Immunology of beta-cell destruction

The pancreatic islet beta-cells are the target for an autoimmune process that eventually results in an inability to control blood glucose due to the lack of insulin. The different steps that eventually lead to the complete loss of the beta-cells are reviewed to include the very first step of a triggering event that initiates the development of beta-cell autoimmunity to the last step of appearance of islet-cell autoantibodies, which may mark that insulitis is about to form. The observations that the initial beta-cell destruction by virus or other environmental factors triggers islet autoimmunity not in the islets but in the draining pancreatic lymph nodes are reviewed along with possible basic mechanisms of loss of tolerance to islet autoantigens. Once islet autoimmunity is established the question is how beta-cells are progressively killed by autoreactive lymphocytes which eventually results in chronic insulitis. Many of these series of events have been dissected in spontaneously diabetic mice or rats, but controlled clinical trials have shown that rodent observations are not always translated into mechanisms in humans. Attempts are therefore needed to clarify the step 1 triggering mechanisms and the step to chronic autoimmune insulitis to develop evidence-based treatment approaches to prevent type 1 diabetes.

[Patient education for children and adolescents with chronic diseases]

The education of children with chronic diseases and of their parents is a treatment procedure that must be integrated into the management of the child's disease: it is essential for his or her physical and psychological health and quality of life. This continuous process is part of long-term follow-up and of the child's development; it is not a procedure that can be carried out once and for all. The program must include initial, follow-up, and advanced education. Treatment education for parents occurs simultaneously with the child's medical management and has the same requirements as that of the child (which means that the time spent in this education requires financial support). The role of the pediatrics departments serving these children is essential, and they must work with other participants, whose roles are not identical to they perform in education for adult patients. Pediatric patient education requires an interdisciplinary pediatric team with specific skills and appropriate liaison with those involved in other aspects of the child's life (e.g., daycare and school). The child's psychological development is central to the design and implementation of pediatric patient education programs. Knowledge of child development is critical in providing these services for children and adolescents; training in this field is required in addition to that necessary for adult patient education. Epidemiologic findings of the increased incidence of several chronic diseases in children must be considered in decisions about the resources allocated to coping with them. The particularities and requirements of adolescence and its interactions with chronic disease must also be considered in specific patient education programs for adolescents, and in the training and skills of healthcare professionals.

Strategies to prevent type 1 diabetes

Type 1 diabetes is a chronic autoimmune condition resulting from T cell-mediated destruction of the insulin-producing cells in the islets of Langerhans. Its primary cause remains unknown, but it has been established that the clinical presentation is preceded by a long prodrome. This enables individuals at high risk of disease to be identified and offers the possibility of intervention to prevent clinical disease. Many groups are working in this field, concentrating on manipulation of environmental exposures that are potential triggers of autoimmunity and on immunomodulation strategies that aim to prevent destruction of beta-cells. Some interventions have shown promising results in early trials, but effective disease prevention remains elusive. This article reviews current progress in the field.