Marked increase in type 1 diabetes mellitus incidence in children aged 0-14 yr in Victoria, Australia, from 1999 to 2002

Association of CIITA (rs8048002) and CLEC2D (rs2114870) gene variants and type 1 diabetes mellitus

Background

Type I diabetes mellitus (T1DM) is a significant health challenge, especially for children, owing to its chronic autoimmune nature. Although the exact etiology of T1DM remains elusive, the interplay of genetic predisposition, immune responses, and environmental factors are postulated. Genetic factors control immune reactivity against β-cells. Given the pivotal roles of CIITA and CLEC2D genes in modulating a variety of immune pathologies, we hypothesized that genetic variations in CIITA and CLEC2D genes may impact T1DM disease predisposition. This study was designed to explore the association between gene polymorphisms in CIITA (rs8048002) and CLEC2D (rs2114870) and type 1 diabetes (T1DM), with a focus on analyzing the functional consequence of those gene variants.

Methods

The study enlisted 178 healthy controls and 148 individuals with type 1 diabetes (T1DM) from Suez Canal University Hospital. Genotyping for CIITA and CLEC2D was done using allelic-discrimination polymerase chain reaction (PCR). Levels of glycated hemoglobin (HbA1c) and lipid profiles were determined through automated analyzer, while fasting blood glucose and insulin serum levels were measured using the enzyme-linked immunosorbent assay (ELISA) technique. RegulomeDB was used to examine the regulatory functions of CIITA (rs8048002) and CLEC2D (rs2114870) gene variants.

Results

Analysis of the genotype distribution of the CIITA rs8048002 polymorphism revealed a significantly higher prevalence of the rare C allele in T1DM patients compared to the control group (OR = 1.77; P = 0.001). Both the CIITA rs8048002 heterozygote TC genotype (OR = 1.93; P = 0.005) and the rare homozygote CC genotype (OR = 3.62; P = 0.006) were significantly more frequent in children with T1DM when compared to the control group. Conversely, the rare A allele of CLEC2D rs2114870 was found to be significantly less frequent in T1DM children relative to the control group (OR = 0.58; P = 0.002). The heterozygote GA genotype (OR = 0.61; P = 0.033) and the rare homozygote AA genotype (OR = 0.25; P = 0.004) were also significantly less frequent in T1DM patients compared to the control group. Both CIITA (rs8048002) and CLEC2D (rs2114870) gene variants were predicted to have regulatory functions, indicated by a RegulomeDB score of (1f) for each.

Conclusion

The rare C allele of CIITA rs8048002 genetic variant was associated with an increased risk of developing T1DM, while the less common A allele of CLEC2D rs2114870 was associated with a reduced risk of T1DM.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-024-01402-w.

Incidence and trends of type 1 diabetes before and after 2000 in the Western Pacific Region: A systematic review and meta-analysis

OBJECTIVES

To undertake a systematic review of publications describing Type 1 diabetes (T1DM) incidence, trends over time and associated factors in the Western Pacific Region (WPR).

METHODS

As per the PROSPERO-registered (CRD42019122646) protocol English (MEDLINE, Embase, Global Health) and Chinese data-bases (China National Knowledge Infrastructure, VIP, Wanfang) from onset to 31/12/2019 were searched for T1DM incidence in the WPR. Country level data extracted included annual crude incidence rates by sex, number of new cases per annum (p.a.) and cumulatively, and the population at-risk. A meta-analysis for T1DM incidence was performed (by region and narrow age-bands, where possible) with subgroup analyses by time and by region.

FINDINGS

Forty-five population-based studies (21 from China), published 1973-2017, estimated T1DM incidence, mostly in youth, in 11 WPR countries. After 2000, mean annual T1DM incidence/100,000 person years aged 0-14 years ranged from 0.9 (95 % confidence intervals (CI), 0.6-1.3) in Fiji to 23.2 (95 % CI, 21.3-25.2) in Australia. The mean annual increase over time ranged from 2.8 % in Australia (1990-2002) to 14.2 % in Shanghai (1997-2011). T1DM incidence increased most in China (2.7-fold over 30-years) then Thailand (2-fold over 15-years). Most studies documented increasing incidence with age, though only two studies included people aged ≥ 20 years. Many, but not all studies reported significantly higher T1DM incidence in females vs. males.

CONCLUSION

T1DM incidence in the WPR is generally increasing, varying by age, sex, time and country. Results increase understanding of regional T1DM incidence and inform research and healthcare strategies.

Prevalence and incidence of type 1 diabetes in the world: a systematic review and meta-analysis

Background: Diabetes is referred to a group of diseases characterized by high glucose levels in blood. It is caused by a deficiency in the production or function of insulin or both, which can occur because of different reasons, resulting in protein and lipid metabolic disorders. The aim of this study was to systematically review the prevalence and incidence of type 1 diabetes in the world. Methods: A systematic search of resources was conducted to investigate the prevalence and incidence of type 1 diabetes in the world. The databases of Medline (via PubMed and Ovid),ProQuest, Scopus, and Web of Science from January 1980 to September 2019 were searched to locate English articles. The located articles were screened in multiple levels of title, abstract,and full-text and final studies that met the inclusion criteria were retrieved and included in the study. Results: From 1202 located articles, 193 studies were included in this systematic review. The results of meta-analysis showed that the incidence of type 1 diabetes was 15 per 100,000 people and the prevalence was 9.5% (95% CI: 0.07 to 0.12) in the world, which was statistically significant. Conclusion: According to the results, the incidence and prevalence of type 1 diabetes are increasing in the world. As a result, insulin will be difficult to access and afford, especially in underdeveloped and developing countries.

Geographical variation in the incidence of type 1 diabetes in the Nordic countries: A study within NordicDiabKids

BACKGROUND

The incidence of type 1 diabetes (T1D) is high in the Nordic countries with geographic differences between as well as within countries.

OBJECTIVE

To describe the geographical distribution of the incidence of T1D among children in four Nordic countries, an area where the population is considered genetically similar.

METHODS

Data on children 0 to 14 years of age and diagnosed with T1D 2006 to 2011 was collected from four Nordic national pediatric quality diabetes registries. Data included year of diagnosis (2006-2011), sex, and age at diagnosis. Figures for number of children at risk during 2006 to 2011-as well as total population, proportion with foreign background and size of populated areas of geographic regions-were collected from official statistics.

RESULTS

The total incidence during the study period for all four countries was 35.7/100 000 person years but differed between the countries (range 18.2-44.1; P < .001). The incidence difference between the countries was most obvious in the highest age group, 10 to 14 years of age, whereas there was no difference in the youngest age group 0 to 5 years of age. Iceland had similar incidence in the entire country, whereas the other countries had areas with different incidence. Densely populated areas, such as major cities, had the lowest incidence.

CONCLUSION

The incidence of T1D differed between the Nordic countries and also between the neighboring countries and generally decreased with population density. This indicates that environmental factors may contribute to the level of incidence of T1D.

Australasian Diabetes Data Network: Building a Collaborative Resource

Australasia is a region with a high incidence of type 1 diabetes (T1D). There are approximately 140 000 individuals with T1D, and of these 10 000 are children. Although the region covers a huge geographical area, most children with T1D are managed by tertiary academic centers in the major capital cities. Local longitudinal data collection has been in place for several decades in most of these centers, however ongoing national data collection had not been attempted. In 2012, with funding from the Juvenile Diabetes Research Foundation (JDRF) Australian Type 1 Clinical Research Network, a national collaboration was formed to provide ongoing longitudinal collection of T1D patient characteristics and outcomes. The initial phase of this collaboration, known as the Australasian Diabetes Data Network or ADDN, was led by the Australasian Paediatric Endocrine Group (APEG) and thus included only children and adolescents. The next phase, commenced in 2016, will see adult sites added through collaboration with the Australian Diabetes Society (ADS). As most of the initial centers had longitudinal data collection in place the model employed was to establish the transfer and collation of data already collected into a central database. This required the definition of a common data dictionary, ethics and governance procedures and the employment of technology to enable efficient and accurate information transfer and accessibility. The ADDN project received widespread support from the diabetes research community with study investigators representing 20 pediatric centers across the region. The first phase focused on the 5 largest centers and at the end of 2015 these centers were uploading patient data to the ADDN database on a quarterly basis resulting in 5271 patients with 83 506 diabetes visits.

The Impact of Diabetes on Brain Function in Childhood and Adolescence

A constant supply of glucose to the brain is critical for normal cerebral metabolism. The dysglycemia of type 1 diabetes (T1D) can affect activity, survival, and function of neural cells. Clinical studies in T1D have shown impairments in brain morphology and function. The most neurotoxic milieu seems to be young age and/or diabetic ketoacidosis at onset, severe hypoglycemia under the age of 6 years followed by chronic hyperglycemia. Adverse cognitive outcomes seem to be associated with poorer mental health outcomes. It is imperative to improve outcomes by investigating the mechanisms of injury so that neuroprotective strategies independent of glycemia can be identified.

Sexual dimorphism in autoimmunity

Autoimmune diseases occur when the immune system attacks and destroys the organs and tissues of its own host. Autoimmunity is the third most common type of disease in the United States. Because there is no cure for autoimmunity, it is extremely important to study the mechanisms that trigger these diseases. Most autoimmune diseases predominantly affect females, indicating a strong sex bias. Various factors, including sex hormones, the presence or absence of a second X chromosome, and sex-specific gut microbiota can influence gene expression in a sex-specific way. These changes in gene expression may, in turn, lead to susceptibility or protection from autoimmunity, creating a sex bias for autoimmune diseases. In this Review we discuss recent findings in the field of sex-dependent regulation of gene expression and autoimmunity.

Enterovirus infection is associated with an increased risk of childhood type 1 diabetes in Taiwan: a nationwide population-based cohort study

AIMS/HYPOTHESIS

This study compared the incidence rate of type 1 diabetes in children diagnosed with enterovirus (EV) infections with that in age- and sex-matched children without EV infection in a population-based cohort. In addition, we examined whether the direction or magnitude of the association between EV infection and type 1 diabetes differs according to atopic disease status in children.

METHODS

We used insurance claims data from Taiwan's National Health Insurance Research Database to derive type 1 diabetes incidence in children aged up to 18 years with or without a diagnosis of EV infection during 2000-2008. Incidence rate ratios and HRs of type 1 diabetes for EV infection were estimated by Poisson regression and Cox's proportional hazard regression model.

RESULTS

Overall incidence of type 1 diabetes was higher in the EV than in the non-EV infection cohort (5.73 vs 3.89 per 100,000 person-years; incidence rate ratio 1.48 [95% CI 1.19, 1.83]), with an adjusted HR of 1.48 (95% CI 1.19, 1.83). Among children without EV, incidence increased with age at diagnosis of EV infection, except in those aged 5-10 years. The HRs of type 1 diabetes in children with allergic rhinitis, bronchial asthma or either one of these atopic diseases showed more variation than in those children without these diseases.

CONCLUSIONS/INTERPRETATION

This nationwide retrospective cohort study found a positive correlation between type 1 diabetes and EV infection. The results suggest that a preventive strategy, such as an effective vaccine against EV infection, may lessen the incidence of type 1 diabetes in Taiwan.

Infectious disease at gluten introduction and risk of childhood diabetes mellitus

OBJECTIVES

To investigate the risk of future diabetes mellitus type 1 (T1D) in children who suffered from infection at time of gluten introduction.

STUDY DESIGN

Population-based prospective study. Parents filled out a diary at home. We hereby obtained data on date of gluten introduction, breastfeeding duration, and infections in 9414 children born in the southeast of Sweden from October 1, 1997, through October 1, 1999 (the All Babies in Southeast Sweden cohort). The Cox proportional hazards model was used to investigate the risk of future T1D until February 1, 2012, among children with infection at time of gluten introduction.

RESULTS

Forty-six children (0.5%) developed T1D and were compared with 9368 reference children from the general population. Some 10 of 46 children with later T1D had an infection at time of gluten introduction (22%) compared with 2520 reference children (27%, P=.43). Later T1D was not associated with age at end of breastfeeding, age at any infection, or age at gluten introduction. Breastfeeding at time of gluten introduction was not protective against future T1D (hazard ratio 1.2; 95% CI, 0.5-2.7). In our final model, when we adjusted for age at gluten introduction, age at infection, and breastfeeding duration, infection at time of gluten introduction did not influence the risk of future T1D (hazard ratio 0.8; 95% CI, 0.3-1.6).

CONCLUSION

Infection at time of gluten introduction is not a major risk factor for future T1D in nonselected children.

Geography does not limit optimal diabetes care: use of a tertiary centre model of care in an outreach service for type 1 diabetes mellitus

AIM

Young people with type 1 diabetes mellitus living in rural and regional Australia have previously been shown to have limited access to specialised diabetes services. The Royal Children's Hospital Melbourne has been running diabetes outreach clinics to Western Victoria, Australia, for over 13 years. We aim to evaluate this service by comparing the outcomes of three outreach clinics with our urban diabetes clinic at the Royal Children's Hospital Melbourne.

METHODS

We examine our tertiary, multidisciplinary team-based model of care, where visiting specialist medical staff work alongside local allied health teams. The local teams provide interim care between clinics utilising the same protocols and treatment practices as the tertiary centre. Longitudinal data encapsulating the years 2005-2010, as a cohort study with a control group, are reviewed.

RESULTS

A total of 69 rural patients were compared with 1387 metropolitan patients. Metabolic control was comparable, with no difference in mean HbA1c (8.3%/67 mmol/mol for both groups). Treatment options varied slightly at diagnosis, while insulin pump usage was comparable between treatment settings (20.3% rural compared with 27.6% urban, P = 0.19). Of note was that the number of visits per year was higher in the rural group (3.3 per year rural compared with 2.7 urban, P < 0.001).

CONCLUSIONS

We conclude that the outreach service is able to provide a comparable level of care when the urban model is translated to a rural setting. This model may be further able to be extrapolated to other geographic areas and also other chronic health conditions of childhood.

Epidemiology of childhood type 1 diabetes mellitus in Nile Delta, northern Egypt - a retrospective study

OBJECTIVE

The geographical incidence of type 1 diabetes mellitus (T1DM) varies widely worldwide. Both genetic and environmental factors have been implicated, although environmental factors are still speculative and elusive. More epidemiological studies are needed to uncover such factors. To date, there are no reported studies on the epidemiology of childhood T1DM in Nile Delta, Egypt. We aimed to define the incidence, prevalence and demographic characteristics of T1DM in children (0-18 years) living in the Nile Delta region, one of the most densely populated areas in Egypt.

METHODS

The study included all T1DM patients aged 0-18 years who lived in the Nile Delta region of Egypt and who were either diagnosed at or referred to Mansoura University Children's Hospital (MUCH) between 1 January 1994 and 31 December 2011. The hospital files of the patients were reviewed. General population data on the 0-18 year age group in the Nile Delta governorates were also presented.

RESULTS

From a total of 1600 T1DM patients, 891 (55.7%) were females (p=0.000) and 935 (58.4%) were from rural areas (p=0.000). Calculated age-adjusted incidence of T1DM in 1996, 2006 and 2011 were 0.7, 2.0 and 3.1/10(5)/year, respectively, while calculated age-adjusted prevalence of T1DM in the same years were 1.9, 15.5 and 26.8/10(5)/year, respectively. Patients presented most frequently in the 5-10 year age group (p<0.000) and in winter months (p=0.009).

CONCLUSION

In this first childhood T1DM epidemiology study in the Nile Delta region of Egypt, T1DM incidence and prevalence were found to show an increase over the past 18 years (1994-2011). Incidence and prevalence were higher in females and more cases were found to originate from rural areas.

Rising incidence of type 1 diabetes in Belgrade children aged 0-14 years in the period from 1982 to 2005

BACKGROUND

Type 1 diabetes (T1DM) is an autoimmune disease in which both genetic and environmental factors play a role in the etiology.

AIM

The aim of this study was to analyze the incidence of T1DM.

METHODS

A retrospective technique was used to register all newly diagnosed cases of T1DM in Belgrade (Serbia) children at the age of 0- 14 yr between 1982 and 2005. The incidence was adjusted directly by age using the Segi's world population as the standard. A total of 702 cases was identified from the two sources: patients' records from two pediatric hospitals in Belgrade referent for the disease, and from the population based register.

RESULTS

The average annual age adjusted incidence rate of T1DM for Belgrade was 10.4/100,000 [95% confidence interval (95% CI)=3.8-15.4]. It was slightly higher in boys than in girls. The age-specific annual incidence rates (per 100,000) for the age groups 0-4, 5-9, and 10-14 were 5.5 (95% CI=4.5-6.7), 11.9 (95% CI=10.5-13.5), and 15.4 (95% CI=13.8-17.1), respectively. Over the 24 yr incidence rates significantly increased by 8.5% for boys and 3.0% for girls. The highest increase of incidence rate was in the 5-9 age group.

DISCUSSION

The results obtained are in line with data from other studies showing that the incidence of T1DM has been increasing in almost all populations worldwide.

How do childhood diagnoses of type 1 diabetes cluster in time?

Background

Previous studies have indicated that type 1 diabetes may have an infectious origin. The presence of temporal clustering—an irregular temporal distribution of cases—would provide additional evidence that occurrence may be linked with an agent that displays epidemicity. We tested for the presence and form of temporal clustering using population-based data from northeast England.

Materials and Methods

The study analysed data on children aged 0–14 years diagnosed with type 1 diabetes during the period 1990–2007 and resident in a defined geographical region of northeast England (Northumberland, Newcastle upon Tyne, and North Tyneside). Tests for temporal clustering by time of diagnosis were applied using a modified version of the Potthoff-Whittinghill method.

Results

The study analysed 468 cases of children diagnosed with type 1 diabetes. There was highly statistically significant evidence of temporal clustering over periods of a few months and over longer time intervals (p<0.001). The clustering within years did not show a consistent seasonal pattern.

Conclusions

The study adds to the growing body of literature that supports the involvement of infectious agents in the aetiology of type 1 diabetes in children. Specifically it suggests that the precipitating agent or agents involved might be an infection that occurs in “mini-epidemics”.

Bayesian analysis of the geographical variation of type 1 diabetes mellitus in under 15 yr olds in northeast Spain, 1991-2009

OBJECTIVE

High variability has been observed in type 1 diabetes mellitus (DM1) incidence rates (IRs) in childhood. The aim of this study was to characterize DM1 in Aragón and to identify variations in the geographical pattern by gender.

METHODS

A descriptive and ecological study was conducted to determine geographical variations in the DM1 incidence for the period 1991-2009. The source of information was the registry of DM1. To determine data completeness, a capture-recapture analysis was performed. Cases were georeferenced according to the Basic Healthcare Area (BHA) of residence. IRs for both genders, age group, 5 yr of diagnosis, and 95% confidence intervals (95% CIs) were calculated. Geographical pattern was studied applying Bayesian statistical model. The standardized incidence ratios (SIRs), smoothed SIR, and the posteriori risk probability (PRP) were represented cartographically for BHA stratified by gender.

RESULTS

The completeness was 93.5%. The global IR was 19.2 cases/10(5) person-years (95% CI: 17.6-20.8), boys 21.4 (95% CI: 19.0-23.8) and girls 16.8 (95% CI: 14.7-19.1). The age-specific rates were significantly lower in the 0-4 year age group with respect to the groups of 5-9 and 10-14 years. For boys, areas with a statistically significant excess of risk were found in the north [smoothed SIR: 118-167.9 and PRP of what the smoothed SIR would be greater than 100 (PRP) above 0.8] and below average risk in the south (smoothed SIR: 65.9-79.1 and PRP less than 0.2).

CONCLUSIONS

DM1 IR presented a north-south geographical pattern in boys. This pattern was not observed in girls or when both genders were considered together. Later studies should include gender as an essential variable.

Phenotypic and environmental factors associated with elevated autoantibodies at clinical onset of paediatric type 1 diabetes mellitus

To examine possible determinants of autoantibody levels at type 1 diabetes mellitus (T1DM) onset. We assessed levels of glutamic acid decarboxylase 65 islet cell antigen (GADA) and anti-insulin antibodies (IAA) in 247 incident T1DM cases presenting <15 years of age in Melbourne from 1st March 2008 to 30th June 2010. 58.9% (142/241) of cases were GADA seropositive and 42.3% (94/222) were IAA seropositive. Factors associated with elevated IAA antibodies included younger age and red hair phenotype. Factors associated with elevated GAD antibodies included lower birthweight and recent eczema. Intriguingly, low recent or past sun exposure was only associated with elevated GADA levels among children presenting at age <5 years, not older (difference in effect, p<0.05 for 4 of 5 associations). These findings show that environmental and phenotypic factors are associated with autoantibody levels at time of presentation for T1DM. We recommend such environmental and phenoytypic factors should be examined in further detail.

Enterovirus infection and type 1 diabetes mellitus: systematic review and meta-analysis of observational molecular studies

OBJECTIVE

To review the association between current enterovirus infection diagnosed with molecular testing and development of autoimmunity or type 1 diabetes.

DESIGN

Systematic review and meta-analysis of observational studies, analysed with random effects models.

DATA SOURCES

PubMed (until May 2010) and Embase (until May 2010), no language restrictions, studies in humans only; reference lists of identified articles; and contact with authors. Study eligibility criteria Cohort or case-control studies measuring enterovirus RNA or viral protein in blood, stool, or tissue of patients with pre-diabetes and diabetes, with adequate data to calculate an odds ratio and 95% confidence intervals.

RESULTS

The 24 papers and two abstracts (all case-control studies) that met the eligibility criteria included 4448 participants. Study design varied greatly, with a high level of statistical heterogeneity. The two separate outcomes were diabetes related autoimmunity or type 1 diabetes. Meta-analysis showed a significant association between enterovirus infection and type 1 diabetes related autoimmunity (odds ratio 3.7, 95% confidence interval 2.1 to 6.8; heterogeneity χ(2)/df = 1.3) and clinical type 1 diabetes (9.8, 5.5 to 17.4; χ(2)/df = 3.2).

CONCLUSIONS

There is a clinically significant association between enterovirus infection, detected with molecular methods, and autoimmunity/type 1 diabetes. Larger prospective studies would be needed to establish a clear temporal relation between enterovirus infection and the development of autoimmunity and type 1 diabetes.

A retrospective study of the incidence of diagnosed Type 1 diabetes among children and adolescents in a large health organization in Israel, 2000-2008

AIMS

To determine the incidence and examine temporal trends of Type 1 diabetes among children aged < 18 years, in a large Israeli health organization.

METHODS

All incident Type 1 diabetes cases diagnosed between 2000 and 2008 were ascertained from an automated diabetes registry based on members' electronic records and validated by comparison with the Israel Juvenile Diabetes Register.

RESULTS

During the study period, a total of 648 incident cases of Type 1 diabetes were identified. The average annual age-and-sex-standardized incidence was 11.09 per 100,000 person-years. There was an annual 5.82% (95% CI 1.80-9.98%) rise in incidence, with a greater relative increase in toddlers under 5 years of age. Incidence increased with age and demonstrated seasonal variation. Mean age at onset of diabetes significantly (P = 0.07) decreased from 10.21 years (SD = 4.48) in 2000-2002 to 9.25 years (SD = 4.54) in 2006-2008. Among very young patients (< 5 years), average blood glucose values at diagnosis dropped from 32.4 mmol/l (SD = 9.5) to 19.5 mmol/l (SD = 11.0) over the study period, with little change in average glucose for older children.

CONCLUSIONS

Incidence of diagnosed Type 1 diabetes continues to increase in Israel at a rate that is high compared with similar American and European populations. At the same time, the clinical presentation of children is changing.

Population density determines the direction of the association between ambient ultraviolet radiation and type 1 diabetes incidence

BACKGROUND

Type 1 diabetes incidence has increased rapidly over the last 20 years, and ecological studies show inverse latitudinal gradients for both incidence and prevalence. Some studies have found season of birth or season of diagnosis effects. Together these findings suggest an important role for environmental factors in disease etiology.

OBJECTIVE

To examine whether type 1 diabetes incidence varies in relation to ambient ultraviolet radiation (UVR) in Australian children.

METHODS

We used case records of 4773 children aged 0-14 yr from the Australian National Diabetes Register to estimate type 1 diabetes incidence in relation to residential ambient UVR, both as a continuous variable and in four categories. We examined season of birth and season of diagnosis and variation in these parameters and in age at diagnosis, in relation to ambient UVR.

RESULTS

Overall incidence was 20 per 100 000 population with no sex difference. There was a statistically significant trend toward winter diagnosis (adjusted RR = 1.22, 95% CI 1.13-1.33, p<0.001) but no apparent season of birth effect. Incidence in the highest UVR category was significantly lower than in the lowest UVR category (RR = 0.85, 95% CI 0.75-0.96). We found an inverse association between incidence and ambient UVR that was present only at low population densities; at high population densities type 1 diabetes incidence increased with increasing ambient UVR.

CONCLUSION

In low population density, largely rural environments, ambient UVR may better reflect the personal UV dose, with the latter being protective for the development of type 1 diabetes. This effect is lost or reversed in high population density, largely urban, environments.

Gene therapy in diabetes

Type 1 diabetes (T1D) is a chronic autoimmune disease, whereby auto-reactive cytotoxic T cells target and destroy insulin-secreting β-cells in pancreatic islets leading to insulin deficiency and subsequent hyperglycemia. These individuals require multiple daily insulin injections every day of their life without which they will develop life-threatening diabetic ketoacidosis (DKA) and die. Gene therapy by viral vector and non-viral transduction may be useful techniques to treat T1D as it can be applied from many different angles; such as the suppression of autoreactive T cells to prevent islet destruction (prophylactic) or the replacement of the insulin gene (post-disease). The need for a better method for providing euglycemia arose from insufficient numbers of cadaver islets for transplantation and the immunosuppression required post-transplant. Ectopic expression of insulin or islet modification have been examined, but not perfected. This review examines the various gene transfer methods, gene therapy techniques used to date and promising novel techniques for the maintenance of euglycemia in the treatment of T1D.

Cardiac complications and mortality rates in diabetic patients following non-cardiac surgery in an Australian teaching hospital

This retrospective study of diabetic patients undergoing non-cardiac surgery has identified that a greater number of patients are at risk of cardiac complications and death in the perioperative period than had previously been suggested. As well as insulin-dependent diabetic patients and patients with elevated creatinine (> 178 micromol/l) as previously found, our study suggests that non-insulin-dependent diabetic patients and patients with creatinine > 120 micromol/l are also at increased risk of cardiac complications and death following non-cardiac surgery. This increases by a factor of six those diabetic patients at risk of perioperative complications from non-cardiac surgery and also increases the number of patients with renal failure similarly at risk. The study confirms similar risks of cardiac complications and death to other recently published data and suggests ongoing comparisons will contribute to quality assurance activities in anaesthesia and surgery.

Australia's national trends in the incidence of Type 1 diabetes in 0-14-year-olds, 2000-2006

AIMS

To determine the national incidence of Type 1 diabetes in children aged 0-14 years and examine trends in incidence between 2000 and 2006 by age, sex and calendar year.

METHODS

Case ascertainment was from the Australian National Diabetes Register, a prospective population-based incidence register established in 1999, with two sources of ascertainment: the National Diabetes Services Scheme and the Australasian Paediatric Endocrine Group's state-based registers. Denominator data were from the Australian Bureau of Statistics.

RESULTS

There were 6350 new cases of Type 1 diabetes (3323 boys and 3027 girls). Case ascertainment was 97.1% complete using the capture-recapture method. The mean adjusted incidence rate for 2000-2006 was 21.6 per 100,000 person-years [95% confidence interval (CI) 21.0, 22.1], and increased from 19.8 in 2000 to 23.4 per 100,000 in 2006, an average increase of 2.8% (95% CI 1.5, 4.1) per year. Mean incidence for the 7-year period increased with age, and was significantly higher in boys aged 0-4 years and 10-14 years than in girls of the same age.

CONCLUSIONS

The incidence of Type 1 diabetes among 0-14-year-olds in Australia is very high compared with available data from many other countries. The rate of increase observed globally in the last decade has continued well into this decade in Australia. The rising incidence cannot be explained by changes in genetic susceptibility; there is an urgent need to examine the environmental factors that have contributed to this increase. The findings of this study also have important implications for resource planning.

Association between early-life factors and risk of child-onset Crohn's disease among Victorian children born 1983-1998: a birth cohort study

BACKGROUND

The incidence of Crohn's disease (CD) with onset before age 16 has increased. Several perinatal characteristics have been associated with CD. Our objective was to examine the temporal change in CD incidence by period of birth and the extent that this could be attributed to perinatal characteristics associated with higher CD risk.

METHODS

A record linkage study was conducted utilizing the perinatal records of Victorian births 1983-1998 inclusive and a state-based CD registry. Proportional hazards models were used to investigate the perinatal factors in relation to the onset of CD by age 16. Further, a nested case control study was conducted to examine the association between sibling exposure and CD risk.

RESULTS

The CD incidence rate for births 1983-1998 was 2.01 (95% confidence interval [CI] 1.79, 2.27) per 100,000 child-years. A birth cohort effect was demonstrated, with higher CD risk for 1992-1998 versus 1983-1991 births (hazard ratio [HR] 1.56; 95% CI 1.18, 2.06). Perinatal characteristics associated with higher CD risk included urban location, higher socioeconomic status, married mother, a congenital abnormality and delivery by elective cesarean section. Sibling exposure during the first 6 years of life was not associated with CD risk. The increased CD incidence among more recent births was not accounted for by changes in these measured perinatal factors.

CONCLUSIONS

The temporal increase in CD incidence documented for births up to 1990 has continued for children born after 1991 and was not accounted for by temporal changes in the measured perinatal factors.

Childhood body mass index (BMI), breastfeeding and risk of Type 1 diabetes: findings from a longitudinal national birth cohort

AIMS

To perform a longitudinal analysis of the association between childhood body mass index (BMI) and later risk of Type 1 diabetes, controlling for socio-economic status, birthweight, height in early and late childhood, breastfeeding history and pubertal status.

METHODS

Analysis of the 1970 British Birth Cohort, followed up at age 5, 10 and 30 years (n = 11,261). Data were available on birthweight, breastfeeding; height, weight, pubertal status, socio-economic status at age 10 years; self-report data on history of diabetes (type, age at onset) at age 30 years. Cox proportional hazards models were used to examine relations of childhood growth, socio-economic status and breastfeeding history to the incidence of Type 1 diabetes between 10 and 30 years of age.

RESULTS

Sixty-one subjects (0.5%) reported Type 1 diabetes at 30 years of age; 47 (77%) reported onset >or= age 10 years. Higher BMI z-score at 10 years predicted higher risk of subsequent Type 1 diabetes (hazard ratio 1.8, 95% confidence interval 1.2 to 2.8, P = 0.01) when adjusted for birthweight, pubertal status, breastfeeding history and socio-economic status. Repeating the model for childhood obesity, the hazard ratio was 3.1 (1.0, 9.3; P = 0.05). Birthweight, breastfeeding, height growth and pubertal timing were not associated with incidence of Type 1 diabetes.

CONCLUSIONS

Higher BMI in childhood independently increased the risk of later Type 1 diabetes, supporting suggestions that obesity may provide a link between Type 1 and Type 2 diabetes. This supports observations of a rise in Type 1 diabetes prevalence. Reduction in childhood obesity may reduce the incidence of Type 1 as well as Type 2 diabetes.

Increasing incidence of type 1 diabetes in children aged 0-14 years in Harbin, China (1990-2000)

AIMS

(1) To determine the incidence of type 1 diabetes mellitus in children aged<15 years in Harbin, China and (2) to examine the trend in incidence over the period from 1990 to 2000.

METHODS

Newly diagnosed cases of type 1 diabetes from 1990 to 2000 were identified among 1,286,154 Chinese children aged 0-14 years in Harbin. The primary source of case ascertainment was from hospital records and the secondary source from the health records of school clinics.

RESULTS

One hundred and three cases were identified during 1990 and 2000. The annual incidence rate was 0.73 per 100,000 (95% CI: 0.59-0.88 per 100,000). No significant difference between males and females in the incidence of type 1 diabetes was observed. The incidence was significantly associated with age. With those aged<5 years as reference, the rate ratios were 2.06 and 4.1 for those aged 5-9 and 10-14 years, respectively. The incidence was higher in urban than in suburban regions, particularly among those aged 10-14 years. No significant seasonality was observed. There was a significant increasing trend in the incidence of type 1 diabetes during the period of 1990 and 2000, with an annual increase of 7.4% (95% CI: 1.6-13.5%).

CONCLUSIONS

There is a significantly increasing trend in the incidence of type 1 diabetes among children in Harbin. Increased number of cases has important implications for diabetes care providers. Understanding the etiology of this rise is critical for developing preventive measures to halt the trend.

Nutritional management of children and adolescents on insulin pump therapy - a survey of Australian Practice

OBJECTIVE

The aims of the survey were to review nutritional care provided to children on insulin pump therapy (IPT) and to identify areas of consensus in medical nutrition therapy. Interventions were compared with existing evidence for best practice.

METHOD

A questionnaire was sent to Dieticians in tertiary pediatric diabetes centers in Australia. Data were gathered on clinic demographics, reasons for commencement of pump therapy, and time spent in medical nutrition therapy. Details of nutrition education strategies were identified. Outcomes from nutrition interventions were reported.

RESULTS

A 100% response rate was achieved (n = 12). A number of nutrition therapy interventions were provided to children on IPT. These included carbohydrate counting, glycemic index (GI), and carbohydrate exchanges. At most centers, nutrition education involved teaching dose adjustment for meals based on the carbohydrate content of the meal with estimations to within 5 g. All centers taught GI. The format of nutrition education, including number and length of consults, varied greatly between centers. Only one center had developed nutrition guidelines for managing insulin pump patients.

CONCLUSIONS

Most pediatric diabetes centers in Australia did not follow nutrition guidelines for the management of children on IPT. There were inconsistencies in the number and length of nutrition consultations provided. Some strategies employed in nutrition education were not supported by existing guidelines for best practice. Differences between centers highlighted gaps in the evidence for nutrition therapy interventions in children on pumps.