Independent effects of socioeconomic status and place of residence on the incidence of childhood type 1 diabetes in Western Australia

Environmental Determinants of Islet Autoimmunity (ENDIA) longitudinal prospective pregnancy to childhood cohort study of Australian children at risk of type 1 diabetes: parental demographics and birth information

INTRODUCTION

The Environmental Determinants of Islet Autoimmunity (ENDIA) Study is an ongoing Australian prospective cohort study investigating how modifiable prenatal and early-life exposures drive the development of islet autoimmunity and type 1 diabetes (T1D) in children. In this profile, we describe the cohort's parental demographics, maternal and neonatal outcomes and human leukocyte antigen (HLA) genotypes.

RESEARCH DESIGN AND METHODS

Inclusion criteria were an unborn child, or infant aged less than 6 months, with a first-degree relative (FDR) with T1D. The primary outcome was persistent islet autoimmunity, with children followed until a T1D diagnosis or 10 years of age. Demographic data were collected at enrollment. Lifestyle, clinical and anthropometric data were collected at each visit during pregnancy and clinical pregnancy and birth data were verified against medical case notes. Data were compared between mothers with and without T1D. HLA genotyping was performed on the ENDIA child and all available FDRs.

RESULTS

The final cohort comprised 1473 infants born to 1214 gestational mothers across 1453 pregnancies, with 80% enrolled during pregnancy. The distribution of familial T1D probands was 62% maternal, 28% paternal and 11% sibling. The frequency of high-risk HLA genotypes was highest in T1D probands, followed by ENDIA infants, and lowest among unaffected family members. Mothers with T1D had higher rates of pregnancy complications and perinatal intervention, and larger babies of shorter gestation. Parent demographics were comparable to the Australian population for age, parity and obesity. A greater percentage of ENDIA parents were Australian born, lived in a major city and had higher socioeconomic advantage and education.

CONCLUSIONS

This comprehensive profile provides the context for understanding ENDIA's scope, methodology, unique strengths and limitations. Now fully recruited, ENDIA will provide unique insights into the roles of early-life factors in the development of islet autoimmunity and T1D in the Australian environment.

TRIAL REGISTRATION NUMBER

ACTRN12613000794707.

Multiple sclerosis prevalence and its relationship with economic status in Afyonkarahisar, Turkey

BACKGROUND

Over the past decade, the prevalence of Multiple Sclerosis (MS) has increased in Turkey. However, the prevalence of MS in Middle Anatolia, specifically Afyonkarahisar, remains unknown. Additionally, the potential link between economic status and MS has not yet been explored in Turkey.

METHODS

A stratified sampling method was employed to select samples from the population residing in Afyonkarahisar City Center, taking into account demographic factors such as income level, sex, and age. The sample size was calculated using the formula N = p.q.Zα2/d2, where an average prevalence rate of 70/100,000 was considered based on previous studies. The minimum sample size was 29,858. Considering incomplete, inaccurate, and low-reliability data, data were collected from 30,500 individuals and 30,408 individuals were evaluated.

RESULTS

The prevalence of Multiple Sclerosis in the center of Afyonkarahisar was 105.2 per 100,000 individuals. Upon investigating the association between economic status and MS prevalence, the findings revealed rates of 193.6 per 100,000 in individuals with high income, contrasting with 80.2 per 100,000 in those with low income. Notably, a heightened prevalence of MS is evident among individuals with higher income levels.

CONCLUSION

This study revealed a significantly elevated prevalence of MS in Afyonkarahisar, the highest in Turkey. The inverse correlation between the prevalence of MS and socioeconomic status is intriguing. Possible reasons for the high prevalence include the relatively new and specific geologic and environmental conditions in the area.

Socioeconomic status and diabetes technology use in youth with type 1 diabetes: a comparison of two funding models

Background

Technology use, including continuous glucose monitoring (CGM) and insulin pump therapy, is associated with improved outcomes in youth with type 1 diabetes (T1D). In 2017 CGM was universally funded for youth with T1D in Australia. In contrast, pump access is primarily accessed through private health insurance, self-funding or philanthropy. The study aim was to investigate the use of diabetes technology across different socioeconomic groups in Australian youth with T1D, in the setting of two contrasting funding models.

Methods

A cross-sectional evaluation of 4957 youth with T1D aged <18 years in the national registry was performed to determine technology use. The Index of Relative Socio-Economic Disadvantage (IRSD) derived from Australian census data is an area-based measure of socioeconomic status (SES). Lower quintiles represent greater disadvantage. IRSD based on most recent postcode of residence was used as a marker of SES. A multivariable generalised linear model adjusting for age, diabetes duration, sex, remoteness classification, and location within Australia was used to determine the association between SES and device use.

Results

CGM use was lower in IRSD quintile 1 in comparison to quintiles 2 to 5 (p<0.001) where uptake across the quintiles was similar. A higher percentage of pump use was observed in the least disadvantaged IRSD quintiles. Compared to the most disadvantaged quintile 1, pump use progressively increased by 16% (95% CI: 4% to 31%) in quintile 2, 19% (6% to 33%) in quintile 3, 35% (21% to 50%) in quintile 4 and 51% (36% to 67%) in the least disadvantaged quintile 5.

Conclusion

In this large national dataset, use of diabetes technologies was found to differ across socioeconomic groups. For nationally subsidised CGM, use was similar across socioeconomic groups with the exception of the most disadvantaged quintile, an important finding requiring further investigation into barriers to CGM use within a nationally subsidised model. User pays funding models for pump therapy result in lower use with socioeconomic disadvantage, highlighting inequities in this funding approach. For the full benefits of diabetes technology to be realised, equitable access to pump therapy needs to be a health policy priority.

Predicting the development of T1D and identifying its Key Performance Indicators in children; a case-control study in Saudi Arabia

The increasing incidence of type 1 diabetes (T1D) in children is a growing global concern. It is known that genetic and environmental factors contribute to childhood T1D. An optimal model to predict the development of T1D in children using Key Performance Indicators (KPIs) would aid medical practitioners in developing intervention plans. This paper for the first time has built a model to predict the risk of developing T1D and identify its significant KPIs in children aged (0-14) in Saudi Arabia. Machine learning methods, namely Logistic Regression, Random Forest, Support Vector Machine, Naive Bayes, and Artificial Neural Network have been utilised and compared for their relative performance. Analyses were performed in a population-based case-control study from three Saudi Arabian regions. The dataset (n = 1,142) contained demographic and socioeconomic status, genetic and disease history, nutrition history, obstetric history, and maternal characteristics. The comparison between case and control groups showed that most children (cases = 68% and controls = 88%) are from urban areas, 69% (cases) and 66% (control) were delivered after a full-term pregnancy and 31% of cases group were delivered by caesarean, which was higher than the controls (χ2 = 4.12, P-value = 0.042). Models were built using all available environmental and family history factors. The efficacy of models was evaluated using Area Under the Curve, Sensitivity, F Score and Precision. Full logistic regression outperformed other models with Accuracy = 0.77, Sensitivity, F Score and Precision of 0.70, and AUC = 0.83. The most significant KPIs were early exposure to cow's milk (OR = 2.92, P = 0.000), birth weight >4 Kg (OR = 3.11, P = 0.007), residency(rural) (OR = 3.74, P = 0.000), family history (first and second degree), and maternal age >25 years. The results presented here can assist healthcare providers in collecting and monitoring influential KPIs and developing intervention strategies to reduce the childhood T1D incidence rate in Saudi Arabia.

Parental socio-economic position and the risk of type 1 diabetes in children and young adults in Denmark: A nation-wide register-based study

AIM

Diabetes mellitus type 1 is one of the most common serious chronic diseases in childhood and the incidence is increasing. Insight into risk factors may inform our etiologic understanding of the disease and subsequent prevention. Any socio-economic gradient in disease risk indicates a potential for prevention, since this points towards socially patterned environmental risk factors. The aim of this study was to investigate the association between measures of parental socio-economic position and the onset of type 1 diabetes in offspring based on individual data in the entire Danish population.

METHODS

In a study population of all children born in Denmark between 1 January 1987 and 31 December 2010, we examined the association between parental socio-economic position and the risk of type 1 diabetes up to the age of 25 years. The risk of type 1 diabetes was estimated according to maternal education, paternal education and household income using Cox proportional hazards regression, with adjustments for the a priori selected confounding variables: year of birth, maternal age at birth and parental type 1 diabetes.

RESULTS

In the study population of 1,433,584 children, a total of 4610 developed type 1 diabetes. We found no clear pattern in type 1 diabetes risk according to parental educational attainment or parental household income.

CONCLUSIONS

In this large population covering study of the risk of type 1 diabetes according to individual-level parental socio-economic position, we found no strong indication of a socially patterned disease risk.

The impact of race and socioeconomic factors on paediatric diabetes

There are over 29,000 children and young people (CYP) with Type 1 diabetes mellitus (T1DM) in England and Wales and another 726 with Type 2 diabetes mellitus (T2DM). There is little effect of deprivation on the prevalence of T1DM whereas the association of deprivation on the percentage of CYP with T2DM is striking with 45% of cases drawn from the most deprived backgrounds. A number that has not changed over the last 4 years. Data from the UK and USA as well as other countries demonstrate the impact of deprivation on outcomes in diabetes mellitus with clear effects on measures of long-term control and complications. In the UK black CYP had higher glycosylated haemoglobin (HbA1c) values compared to other groups. Within the black group, CYP from a Caribbean background had a higher mean HbA1c (77.0 mmol/mol (9.2%)) than those from Africa (70.4 mmol/mol (8.6%)). Treatment regimen (multiple daily injections or insulin pump therapy) explained the largest proportion of the variability in HbA1c followed by deprivation. Those in the least deprived areas had an average HbA1c 5.88 mmol/mol (0.5%) lower than those living in the most deprived areas. The picture is complex as UK data also show that deprivation and ethnicity is associated with less use of technology that is likely to improve diabetes control. Increased usage of pump therapy and continuous glucose monitoring was associated with a younger age of patient (less than 10 years of age), living in the least deprived areas and white ethnicity. This gap between pump usage amongst CYP with T1DM living in the most and least deprived areas has widened with time. In 2014/15 the gap was 7.9% and by 2018/19 had increased to 13.5%. To attain an equitable service for CYP with diabetes mellitus we need to consider interventions at the patient, health care professional, community, and health care system levels.

Twenty years of pediatric diabetes surveillance: what do we know and why it matters

SEARCH for Diabetes in Youth (SEARCH) was initiated in 2000 as a multicenter study to address major gaps in the understanding of childhood diabetes in the United States. An active registry of youth diagnosed with diabetes at age <20 years since 2002 assessed prevalence, annual incidence, and trends by age, race/ethnicity, sex, and diabetes type. An observational cohort nested within the population-based registry was established to assess the natural history and risk factors for acute and chronic diabetes-related complications, as well as the quality of care and quality of life of children and adolescents with diabetes from diagnosis into young adulthood. SEARCH findings have contributed to a better understanding of the complex and heterogeneous nature of youth-onset diabetes. Continued surveillance of the burden and risk of type 1 and type 2 diabetes is important to track and monitor incidence and prevalence within the population. SEARCH reported evidence of early diabetes complications highlighting that continuing the long-term follow-up of youth with diabetes is necessary to further our understanding of its natural history and to develop the most appropriate approaches to primary, secondary, and tertiary prevention of diabetes and its complications. This review summarizes two decades of research and suggests avenues for further work.

Type 1 Diabetes incidence among youth in Utah: A geographical analysis

Type 1 Diabetes (T1D) poses an increasing threat to public health, as incidence rates continue to rise globally. However, the etiology of T1D is still poorly understood, especially from the perspective of geography. The objective of this research is to examine the incidence of T1D among youth and to identify high-risk clusters and their association with socio-demographic and geographic variables. The study area was the entire state of Utah and included youth with T1D from birth to 19 years of age from 1998 to 2015 (n = 4161). Spatial clustering was measured both globally and locally using the Moran's I statistic and spatial scan statistic. Ordinary least squares (OLS) regression was used to measure the association of high-risk clusters with certain risk factors at the Census Block Group (CBG) level. The mean age at diagnosis was 9.3 years old. The mean incidence rate was 25.67 per 100,000 person-years (95% CI, 24.57-26.75). The incidence rate increased by 14%, from 23.94 per100,000 person-years in 1998 to 27.98 per 100,000 person-years in 2015, with an annual increase of 0.80%. The results of the spatial scan statistic found 42 high-risk clusters throughout the state. OLS regression analysis found a significant association with median household income, population density, and latitude. This study provides evidence that incidence rates of T1D are increasing annually in the state of Utah and that significant geographic high-risk clusters are associated with socio-demographic and geographic factors.

Incidence of type 1 diabetes by socio-demographic characteristics among South Australian children: Whole-of-population study

AIM

To describe and compare the incidence of type 1 diabetes (T1D) in South Australia by individual and area-level socio-economic characteristics among children aged ≤11 years.

METHODS

This is a whole-of-population, data linkage study (n = 231 685) conducted in South Australia, and included children born from 2002 to 2013, hospitalisation followed from 2002 to 2014. The study used de-identified, linked administrative hospitalisation, birth and perinatal data from the South Australian Early Childhood Data Project. Incidence was calculated by identifying T1D cases from T1D-related hospitalisations using International Classification of Disease, 10th Revision, Australian Modification diagnosis codes (E10, E101-E109).

RESULTS

Overall, 333 children aged ≤11 years (173 boys) were identified as having T1D. The T1D incidence rate was 23.0 per 100 000 person-years (95% confidence interval (CI): 20.7-25.7), with no sex difference. T1D incidence was higher among children whose mothers were Caucasian, private patients and whose parents were employed. For example, T1D incidence was 26.0 per 100 000 (95% CI: 22.8-29.5) among children with both parents employed, compared to 20.0 per 100 000 (95% CI: 12.3-30.6) among children with both parents unemployed. There was no clear gradient in the association between area-level socio-economic position and T1D, with highest incidence for the fourth quintile (26.5 per 100 000 (95% CI: 20.9-33.1)). The most advantaged area (19.4 per 100 000 (95% CI: 13.8-26.5)) had lower incidence than the most disadvantaged area (23.5 per 100 000 (95% CI: 18.9-28.9)).

CONCLUSION

T1D incidence rates differed depending on the measures of socio-economic characteristics. Individual-level indicators showed higher incidence among more advantaged children; however, there was no clear area-level socio-economic patterning of T1D.

Childhood type 1 diabetes: an environment-wide association study across England

AIMS/HYPOTHESIS

Type 1 diabetes is an autoimmune disease affecting ~400,000 people across the UK. It is likely that environmental factors trigger the disease process in genetically susceptible individuals. We assessed the associations between a wide range of environmental factors and childhood type 1 diabetes incidence in England, using an agnostic, ecological environment-wide association study (EnWAS) approach, to generate hypotheses about environmental triggers.

METHODS

We undertook analyses at the local authority district (LAD) level using a national hospital episode statistics-based incident type 1 diabetes dataset comprising 13,948 individuals with diabetes aged 0-9 years over the period April 2000 to March 2011. We compiled LAD level estimates for a range of potential demographic and environmental risk factors including meteorological, land use and environmental pollution variables. The associations between type 1 diabetes incidence and risk factors were assessed via Poisson regression, disease mapping and ecological regression.

RESULTS

Case counts by LAD varied from 1 to 236 (median 33, interquartile range 24-46). Overall type 1 diabetes incidence was 21.2 (95% CI 20.9, 21.6) per 100,000 individuals. The EnWAS and disease mapping indicated that 15 out of 53 demographic and environmental risk factors were significantly associated with diabetes incidence, after adjusting for multiple testing. These included air pollutants (particulate matter, nitrogen dioxide, nitrogen oxides, carbon monoxide; all inversely associated), as well as lead in soil, radon, outdoor light at night, overcrowding, population density and ethnicity. Disease mapping revealed spatial heterogeneity in type 1 diabetes risk. The ecological regression found an association between type 1 diabetes and the living environment domain of the Index of Multiple Deprivation (RR 0.995; 95% credible interval [CrI] 0.991, 0.998) and radon potential class (RR 1.044; 95% CrI 1.015, 1.074).

CONCLUSIONS/INTERPRETATION

Our analysis identifies a range of demographic and environmental factors associated with type 1 diabetes in children in England.

The Challenges of Identifying Environmental Determinants of Type 1 Diabetes: In Search of the Holy Grail

Type 1 diabetes is the result of autoimmune-mediated destruction and inflammation of the insulin-producing β-cells of the pancreas. The excess morbidity and mortality from its complications coupled with its increasing incidence emphasize the importance to better understand the etiology of this condition. It has a strong genetic component, but a genetic predisposition is not the sole contributor to disease development as only 30% to 50% of identical twins both develop the disease. In addition, there are multiple lines of evidence to support that environmental factors contribute to the pathogenesis of type 1 diabetes. Environmental risk factors that have been proposed include infections, dietary factors, air pollution, vaccines, location of residence, childhood obesity, family environment and stress. Researchers have conducted many observational studies to identify and characterize these potential environmental factors, but findings have been inconsistent or inconclusive. Many studies have had inherent methodological issues in recruitment, participation, defining cases and exposures, and/or data analysis which may limit the interpretability of findings. Identifying and addressing these limitations may allow for greatly needed advances in our understanding of type 1 diabetes. As such, the purpose of this article is to review and discuss the limitations of observational studies that aim to determine environmental risk factors for type 1 diabetes and propose recommendations to overcome them.

Diabetes mellitus literacy in a regional community of a developed country

Background: Prevalence of diabetes mellitus (DM) is on the increase. Yet discrepancies exist in research reports regarding the level of knowledge of the disease in ‘rural versus metropolitan communities’, and ‘developed versus developing countries’. This study examines the level of general knowledge of diabetes among adult community members of a regional city of Australia, whether it is comparable to reports from low-mid income countries. Methods: The study was designed to be a cross-sectional day-time-population survey. Major shopping centres were chosen for convenience sampling of community’s daytime population. A total of 315 participants’ (154 males and 161 females) responses were received. Data were analysed using SPSS – 20 software to identify differences between sub-groups of age stratifications, educational status, gender and the participants assumed knowledgee. The participant’s average knowledge of diabetes symptoms and complications were also assessed. Results: The major finding is that the subgroup who claimed to know ‘very little’ showed equivalent knowledge levels with those who thought they had ‘considerable knowledge’. The females know more about diabetes management than males (P < 0.004); level of knowledge increased with educational status (p < 0.01). These observations were comparable with reports from developing countries. Conclusions: The limited knowledge of diabetes symptoms and complications in the population can be mitigating against early reporting of patients to diabetes clinics in the community. To ensure continuous decline in prevalence rates of diabetes and its complications, the ongoing efforts of diabetes awareness and educational programs need to be improved, particularly with regard to males and school children. (www.actabiomedica.it)

Environmental (Lifestyle) Risk Factors for LADA

BACKGROUND

In order to prevent diabetes it is important to identify common, modifiable risk factors in the population. Such knowledge is extensive for type 2 diabetes but limited for autoimmune forms of diabetes.

OBJECTIVE

This review aims at summarizing the limited literature on potential environmental (lifestyle) risk factors for LADA.

METHODS

A PubMed search identified 15 papers estimating the risk of LADA in relation to lifestyle. These were based on data from two population-based studies; one Swedish case-control study and one Norwegian cohort study.

RESULTS

Studies published to date indicate that the risk of LADA is associated with factors promoting insulin resistance and type 2 diabetes such as overweight, physical inactivity, smoking, low birth weight, sweetened beverage intake and moderate alcohol consumption (protective). Findings also indicate potential effects on autoimmunity exerted by intake of coffee (harmful) and fatty fish (protective). This supports the concept of LADA as being a hybrid form of diabetes with an etiology including factors associated with both insulin resistance and autoimmunity.

CONCLUSION

LADA may in part be preventable through the same lifestyle modifications as type 2 diabetes including weight loss, physical activity and smoking cessation. However, current knowledge is hampered by the small number of studies and the fact that they exclusively are based on Scandinavian populations. There is a great need for additional studies exploring the role of lifestyle factors in the development of LADA.

Is the incidence of type 1 diabetes in children and adolescents stabilising? The first 6 years of a National Register

The Irish Childhood Diabetes National Register (ICDNR) was established in 2008 to define accurately the incidence and monitor the epidemiology of type 1 diabetes (T1D) in the Irish population. Here, we report data from the first 6 years of the National Register and compare with previous national data. Prospective national incident data regarding T1D in those under 15 years resident in Ireland were collected from 2008 to 2013 and national incidence rates (IRs) calculated. Ascertainment completeness was assessed using capture-recapture methodology. The period identified 1566 new cases of T1D, ascertainment reached 96.8 % in 2013. The standardised incidence rate was 27.5 in 2008 stabilising at 28.7 and 28.8 cases /100,000/year in 2012 and 2013. There was no evidence that the incidence changed significantly in the 6-year period either overall or for each age group and gender. There was evidence of a difference in the incidence of T1D across the age groups with the overall incidence highest in the 10-14 year age category. A strong seasonal association was demonstrated.

CONCLUSIONS

This study confirms Ireland as a high-incidence country for type 1 diabetes whilst demonstrating that the previous marked increase in IR from 16.3 cases/100,000/year in 1997 has not continued. Ongoing monitoring through the robust mechanism of the ICDNR is required to clarify whether this is a fluctuation or if the incidence of T1D diabetes has stopped rising in our population. Alternatively, this apparent stabilisation may reflect a shift to a later age at diagnosis. "What is known :" • The incidence of Type 1 diabetes (T1D) is increasing in most populations worldwide although in certain high-incidence populations, it may be stabilising • There was a marked increase in T1D in Ireland between 1997 and 2008 • T1D incidence increases with affluence "What is New:" • The high incidence of T1D in Ireland has been confirmed at 28.8 cases/100,000/year in 2013 and has been effectively stable in the period 2008-2013 • Incidence is highest in Irish 10-14 year olds • Changes in incidence possibly reflecting life style and economic climate • Marked seasonality of diagnosis confirmed.

School performance in children with type 1 diabetes: a contemporary population-based study

AIMS

Our aim was to examine the school performance of children with type 1 diabetes in comparison to their peers, exploring changes over time, and the impact of clinical factors on school performance.

METHODS

The study included data on 666 children with type 1 diabetes from the Western Australia Children's Diabetes Database. (WACDD), a population-based registry, and 3260 school and school year matched non-diabetic children. Records from the National Assessment Program - Literacy and Numeracy (NAPLAN) (2008-2011), which examines four educational outcome domains and is administered annually to all years 3, 5, 7, and 9 children in Australia, were sourced for both groups. Clinical data were obtained for the children with diabetes from the WACDD.

RESULTS

No significant difference was observed between those with type 1 diabetes and their peers, across any of the tested domains and school years analysed. No decline over time was observed, and no decline following diagnosis was observed. Type 1 diabetes was associated with decreased school attendance, 3% fewer days attended per year. Poorer glycaemic control [higher haemoglobin A1c (HbA1c)] was associated with a lower test score [0.2-0.3 SD per 1% (10.9 mmol/mol) increase in HbA1c], and with poorer attendance [1.8% decrease per 1% (10.9 mmol/mol) increase in HbA1c]. No association was observed with history of severe hypoglycaemia, diabetic ketoacidosis or age of onset and school test scores.

CONCLUSION

These results suggest that type 1 diabetes is not associated with a significant decrement in school performance, as assessed by NAPLAN. The association of poorer glycaemic control with poorer school performance serves as further evidence for clinicians to focus on improving glycaemic control.

Trends in childhood type 1 diabetes mellitus incidence in Beijing from 1995 to 2010: a retrospective multicenter study based on hospitalization data

BACKGROUND

The incidence of type 1 diabetes mellitus (T1DM) is increasing rapidly worldwide for children of every age group.

MATERIALS AND METHODS

A retrospective analysis of hospital registration data from five tertiary hospitals in Beijing, China, identified 485 patients (210 boys, 275 girls) younger than 15 years of age with newly diagnosed T1DM between 1995 and 2010.

RESULTS

From 1995 to 2010, the incidence of T1DM in patients <15 years of age ranged from 0.935-3.26 per 100,000 per year. During this period, the average age-standardized incidence rate was 1.7 per 100,000 per year, and the average annual increase in T1DM incidence was 4.36%. The highest rate increases occurred in boys and in patients <5 years of age. For both genders and all age groups, T1DM incidence increased at an accelerated rate after 2006. By 2020, the incidence of T1DM among children in Beijing is projected to increase by a factor of 1.69.

CONCLUSIONS

The incidence of T1DM among patients younger than 15 years of age in Beijing increased from 1995 to 2010, with rates growing at an accelerated pace since 2006. Based on recent trends, we project continued rapid growth in the number of new childhood T1DM cases in Beijing.

Clinical and demographic risk factors associated with mortality during early adulthood in a population-based cohort of childhood-onset type 1 diabetes

AIMS

To calculate standardized mortality ratios and to assess the association between paediatric clinical factors and higher risk of mortality during early adulthood in a population-based cohort of subjects with Type 1 diabetes.

METHODS

Subjects with Type 1 diabetes were identified through the Western Australian Children's Diabetes Database and clinical data for those who reached 18 years of age (n = 1309) were extracted. An age- and sex-matched (without diabetes) comparison cohort (n = 6451) was obtained from the birth registry. Mortality records were obtained from the death registry. Participants were followed up until 31 January 2012. Associations of clinical factors (from clinic visits before 18 years of age) with mortality were assessed using Cox proportional hazard models.

RESULTS

The standardized mortality ratio for all-cause mortality was 1.7 (95% CI 0.7-3.3) for male and 10.1 (95% CI 5.2-17.7) for female subjects with Type 1 diabetes (median age at end of study 25.6 years). The adjusted hazard ratio was 1.5 (95% CI 1.1-2.1) for a 1% increase in mean paediatric HbA1c level, 3.8 (95% CI 0.9-15.3) for four episodes of severe hypoglycaemia relative to zero episodes, and 6.21 (95% CI 1.4-28.4) for a low-level socio-economic background relative to a high-level background.

CONCLUSIONS

People with childhood-onset Type 1 diabetes have higher mortality rates in early adulthood. At particularly high risk are women, those with a history of poor HbA1c levels, those with recurrent severe hypoglycaemia during paediatric management, and those from a low socio-economic background. These groups may benefit from intensified management during transition from paediatric to adult care facilities.

Trends in the incidence of childhood type 1 diabetes mellitus in Beijing based on hospitalization data from 1995 to 2010

OBJECTIVES

To study the incidence trend of type 1 diabetes mellitus (T1DM) in children in Beijing from 1995 to 2010, to compare it with incidences reported worldwide and to predict the requirement of medical resources in the future.

METHODS

This study involved newly diagnosed T1DM cases younger than 15 years of age in the Beijing Children's Hospital from January 1995 to December 2010. We calculated the incidence of T1DM children in Beijing according to hospitalization data and Beijing's population. We defined it as the underestimated incidence rate (UE-IR).

RESULTS

The UE-IRs of T1DM ranged from around 0.88/100,000 to 2.37/100,000 for children in Beijing younger than 15 years of age from 1995 to 2010. The UE-IR increased faster in boys (1.47 times) and in the age group of 0-4 years (1.89 times) after 2003. The UE-IR was greatest in children aged 5-9 years (1.81/100,000) followed by the age of puberty (10-14 years, 1.76/100,000). The predicted number of new T1DM cases in Beijing will increase 1.97 times over the next 10 years.

CONCLUSIONS

The incidence trend of T1DM was increasing gradually in those younger than 15 years of age in Beijing. The incidence of younger children and boys grew faster. The 5- to 14-year-old children represented a high-risk population of T1DM. The number of predicted new T1DM cases will grow rapidly. This means that we should train more health care providers for pediatric diabetes patients, in order to achieve high-quality medical care and to be able to prevent or postpone chronic complications.

Socioeconomic status. The relationship with health and autoimmune diseases

Socioeconomic status (SES) is a hierarchical social classification associated with different outcomes in health and disease. The most important factors influencing SES are income, educational level, occupational class, social class, and ancestry. These factors are closely related to each other as they present certain dependent interactions. Since there is a need to improve the understanding of the concept of SES and the ways it affects health and disease, we review herein the tools currently available to evaluate SES and its relationship with health and autoimmune diseases.

Type I diabetes among children and young adults: the role of country of birth, socioeconomic position and sex

OBJECTIVE

To investigate associations between country of birth, parental country of birth, and education with respect to incidence rate and time trends of type 1 diabetes mellitus (T1DM) among children and young adults.

METHODS

We followed a nation-wide cohort of 4 469 671 males and 4 231 680 females aged 0-30 years between 1969 and 2008. Incidence rate ratios (IRRs) with 95% confidence intervals (CIs) for T1DM were calculated using Poisson regression models. We further calculated age-standardized rates (ASRs) of T1DM, using the world population as standard.

RESULTS

During the study period, the ASR of T1DM increased among children younger than 15 years, but not among young adults (15-30 years). Compared with Swedish-born children, male and female immigrant children had 44 and 42% lower IRR of TIDM, respectively. Among offspring to immigrants, corresponding decreases in IRRs were 27 and 24%, respectively. Compared with children to parents with high education, male children to parents with low education had a 10% decreased IRR of T1DM, while no effect was observed among females. The IRR of T1DM increased with increasing age and calendar time of follow-up in both sexes (p-for trend <0.0001). In young adults, the IRR among immigrants decreased by 32% in males and 22% in females, while corresponding reductions in IRRs were less in offspring to immigrants.

CONCLUSIONS

We found a lower IRR of T1DM among offspring to immigrants, but especially among young immigrants compared with Sweden-born individuals. The findings show that environmental factors are important in the etiology of T1DM.

Incidence of type 1 diabetes mellitus in Turkish children from the southeastern region of the country: a regional report

OBJECTIVE

Variability in the incidence of type 1 diabetes mellitus (T1DM) related to geographical region, ethnic background, gender, and age indicates a need for further epidemiological studies. To date, there are no reported studies on the incidence of T1DM in the pediatric age group from the Southeastern region of Turkey. To define the incidence, demographic and clinical characteristics of T1DM in children 0-14 years of age in Diyarbakir, one of the largest cities in the Southeast region of Turkey.

METHODS

Hospital files of patients with the diagnosis of T1DM were reviewed. Data of all patients diagnosed between 1 June 2010 and 31 May 2011 were evaluated. Population data on the 0-14 age group were obtained from the Turkish Statistical Institute (TSI) reports.

RESULTS

From a total of 41 T1DM patients, 24 (58.5%) were female (male: 41.5%) with a male/female ratio of 1.4. The overall annual incidence of T1DM was 7.2/10(5), being 8.7/10(5) in females and 5.7/10(5) in males. The peak incidence was found to occur at age 5-9 years in the girls and 10-14 years in the boys. Mean age at diagnosis was 8.1±3.8 years. Rate of presentation with diabetic ketoacidosis was 65.9%. Patients applied most frequently in spring and winter months.

CONCLUSIONS

In this first T1DM incidence study on the pediatric age group in Diyarbakir, Turkey, T1DM incidence was found to be similar to that in countries with low-middle incidence.

Variation between countries in the frequency of diabetic ketoacidosis at first presentation of type 1 diabetes in children: a systematic review

AIMS/HYPOTHESIS

Type 1 diabetes is the most frequent endocrine disease in children, with 65,000 children diagnosed worldwide every year. Up to 80% of these children present with diabetic ketoacidosis (DKA), which is associated with both short-term risks and long-term consequences. This study aimed to characterise the worldwide variation in presentation of type 1 diabetes to inform future interventions to reduce this excess morbidity and mortality.

METHODS

This was a systematic review of studies indexed on PubMed, EMBASE, Web of Science, Scopus or CINAHL before March 2011 that included unselected groups of children presenting with new-onset type 1 diabetes, reported the proportion presenting with DKA and used a definition of DKA based on measurement of pH or bicarbonate.

RESULTS

Sixty-five studies of cohorts comprising over 29,000 children in 31 countries were included. The frequency of DKA at diagnosis ranged from 12.8% to 80%, with highest frequencies in the United Arab Emirates, Saudi Arabia and Romania, and the lowest in Sweden, the Slovak Republic and Canada. Multivariable modelling showed the frequency of DKA was inversely associated with gross domestic product, latitude and background incidence of type 1 diabetes.

CONCLUSIONS/INTERPRETATION

This is the first description of the variation in frequency of DKA at presentation of type 1 diabetes in children across countries. It demonstrates large variations that may, at least in part, be explained by different levels of disease awareness and healthcare provision and suggests ways to decrease the excess morbidity and mortality associated with DKA at diagnosis.

Neighborhood context and incidence of type 1 diabetes: the SEARCH for Diabetes in Youth study

Findings regarding type 1 diabetes mellitus (T1DM) and neighborhood-level characteristics are mixed, with few US studies examining the influence of race/ethnicity. We conducted an ecologic study using SEARCH for Diabetes in Youth Study data to explore the association of neighborhood characteristics and T1DM incidence. 2002-2003 incident cases among youth at four SEARCH centers were included. Residential addresses were geocoded to US Census Tract. Standardized incidence ratios tended to increase with increasing education and median household income. Results from Poisson regression mixed models were similar and stable across race/ethnic groups and population density. Our study suggests a relationship of T1DM incidence with neighborhood-level socioeconomic status, independent of individual-level race/ethnic differences.

Neurocognitive outcomes in young adults with early-onset type 1 diabetes: a prospective follow-up study

OBJECTIVE

The aim of this study was to reexamine the neurocognitive function of a cohort of young adults with early-onset type 1 diabetes and compare their cognitive function to a matched control group. We also examined whether cognitive function was related to prospectively obtained severe hypoglycemia history, long-term glycemic control, or severe diabetic ketoacidosis.

RESEARCH DESIGN AND METHODS

Testing included Wechsler Intelligence Scale for Children and Adults, Wechsler Memory Scale, Cattell Culture Fair Intelligence Test (CCFIT), Wisconsin Card Sorting Test (WCST), youth and adult self-report, and Beck Depression Inventory. We tested 34 control subjects (mean ± SE, age 19.5 ± 0.5 years) and 33 type 1 diabetic subjects (age 19.3 ± 0.5 years, age at type 1 diabetes onset 3.3 ± 0.3 years, A1C from diagnosis 8.7 ± 0.1%, and diabetes duration 16.0 ± 0.5 years).

RESULTS

There was no difference in full-scale IQ scores in type 1 diabetic and control subjects (100.7 ± 2.0 vs. 102.5 ± 1.4). There was no difference between groups in memory subtests or in reporting of emotional and behavioral difficulties. The type 1 diabetes group scored lower on the CCFIT for fluid intelligence compared with control subjects (P = 0.028) and also scored lower on WCST with more perseverative errors (P = 0.002) and fewer categories completed (P = 0.022).

CONCLUSIONS

These data suggest no difference in general intellectual ability, memory, and emotional difficulties in our cohort of young adults with early-onset type 1 diabetes compared with control subjects and no deterioration over time. There were, however, findings to suggest subtle changes leading to poorer performance on complex tasks of executive function.

Prevalence of type 1 diabetes mellitus in 6-18-yr-old school children living in Istanbul, Turkey

BACKGROUND

Type 1 diabetes mellitus (T1DM) is among the most common chronic diseases in childhood and the incidence of T1DM is increasing worldwide. There is no actual data regarding the frequency of T1DM in Turkish children.

OBJECTIVES

We aimed to assess current prevalence of T1DM in 6-18-yr-old school children living in Istanbul.

METHODS

Total number of students and children on insulin treatment were reported by the schools, as the first part of the study. At the second step, the study team visited 203 schools for confirmation of the reported data.

RESULTS

One thousand and ninety children in a population of 1 630 751 school children were reported to have T1DM, which made the total prevalence of T1DM 0.67/1000 (95% confidence interval 0.6/1000-0.7/1000). A population of 217 030 children (α=0.05 and β=0.20) from 203 schools were screened. The difference between the reported and detected prevalence was 0.032/1000 (215 detected vs. 222 reported, p>0.05). Comparison of the current data with the prevalence reported in a smaller population in Ankara, Turkey, 16 yr ago, demonstrated that the prevalence of T1DM is higher in the current study (0.46/1000 vs. 0.16/1000, 0.57/1000 vs. 0.34/1000, and 0.92/1000 vs. 0.69/1000 at primary, secondary, and high schools, respectively).

CONCLUSION

This first pediatric T1DM prevalence data in a large pediatric population in Istanbul, Turkey, estimated the prevalence of T1DM as 0.67/1000. This prevalence is 2.5-fold higher than that reported in Ankara, Turkey, in 1993, suggesting that T1DM prevalence is increasing in Turkey as in the other parts of the world.

Early introduction of root vegetables in infancy associated with advanced ß-cell autoimmunity in young children with human leukocyte antigen-conferred susceptibility to Type 1 diabetes

AIMS

Early introduction of supplementary foods has been implicated to play a role in the development of ß-cell autoimmunity. We set out to study the effects of breastfeeding and age at introduction of supplementary foods on the development of ß-cell autoimmunity.

METHODS

A prospective birth cohort of 6069 infants with HLA-DQB-conferred susceptibility to Type 1 diabetes was recruited between 1996 and 2004. Antibodies against islet cells, insulin, glutamate dehydroxylase and islet antigen 2 were measured at 3- to 12-month intervals. The families recorded at home the age at introduction of new foods and, for each visit, completed a structured dietary questionnaire. The endpoint was repeated positivity for islet cell antibodies plus at least one other antibody and/or clinical Type 1 diabetes (n = 265).

RESULTS

Early introduction of root vegetables (by the age of 4 months) was related to increased risk of developing positivity for the endpoint [hazard ratio (95% CI) for the earliest third 1.75 (1.11-2.75) and for the middle third 1.79 (1.22-2.62) compared with the last third (> 4 months), likelihood ratio test P = 0.006], independently of the introduction of other foods and of several putative socio-demographic and perinatal confounding factors. Introducing wheat, rye, oats and/or barley cereals (P = 0.013) and egg (P = 0.031) early was related to an increased risk of the endpoint, but only during the first 3 years of life.

CONCLUSIONS

Early introduction of root vegetables during infancy is independently associated with increased risk of ß-cell autoimmunity among Finnish children with increased genetic susceptibility to Type 1 diabetes.

Prevalance and associations of food insecurity in children with diabetes mellitus

OBJECTIVES

To examine the prevalence of food insecurity in households with a child with insulin-requiring diabetes mellitus (DM), investigate whether food insecurity is associated with poorer DM control, and describe the household characteristics and coping strategies of food-insecure families with a child with DM.

STUDY DESIGN

Telephone interviews were conducted with consecutive consenting families over a 16-month period. Food insecurity was assessed through a validated questionnaire; additional questions elicited demographic information and DM management strategies. Charts were reviewed for hemoglobin A1c (HbA1c). Univariate and logistic regression analyses were performed.

RESULTS

A total of 183 families were interviewed. Food insecurity was present in 21.9% (95% confidence interval, 15.87%-27.85%), significantly higher than the overall prevalences in Nova Scotia (14.6%) and Canada (9.2%). Food insecurity was associated with higher HbA1c level; however, in multivariate analysis, only child's age and parents' education were independent predictors of HbA1c. Children from food-insecure families had higher rates of hospitalization, for which food security status was the only independent predictor. Common characteristics and coping strategies of food-insecure families were identified.

CONCLUSIONS

Food insecurity was more common in families with a child with DM, and the presence of food insecurity was predictive of the child's hospitalization. Risk factors identified in this study should be used to screen for this problem in families with a child with DM.

Rapid increase in the incidence of type 1 diabetes in Polish children from 1989 to 2004, and predictions for 2010 to 2025

AIMS/HYPOTHESIS

We analysed the temporal changes in the incidence of childhood type 1 diabetes and its demographic determinants in Poland from 1989 to 2004, validating the model with data from 1970 to 1989. We also estimated a predictive model of the trends in childhood diabetes incidence for the near future.

METHODS

Children under 15 years with newly diagnosed type 1 diabetes mellitus and drawn from seven regional registries in Poland were ascertained prospectively using the Epidemiology and Prevention of Diabetes study (EURODIAB) criteria. The type 1 diabetes incidence rates (IRs) were analysed in dependency of age, sex, seasonality, geographical region and population density. Time trends in IR were modelled using several approaches.

RESULTS

The average incidence, standardised by age and sex, for 1989 to 2004 was 10.2 per 100,000 persons per year and increased from 5.4 to 17.7. No difference was found between boys and girls, or between urban and rural regions. In children above 4 years, IR was significantly higher in the population of northern Poland than in that of the country's southern part, as well as in the autumn-winter season, this finding being independent of child sex. Based on the trend model obtained, almost 1,600 Polish children aged 0 to 14 years are expected to develop type 1 diabetes in 2010, rising to more than 4,800 in 2025. The estimates suggest at least a fourfold increase of IR between 2005 and 2025, with the highest dynamics of this increment in younger children.

CONCLUSIONS/INTERPRETATION

These estimates show that Poland will have to face a twofold higher increase in childhood type 1 diabetes than predicted for the whole European population. The dramatic increase could have real downstream effects on Poland's healthcare system.

High levels of education are associated with an increased risk of latent autoimmune diabetes in adults: results from the Nord-Trøndelag health study

OBJECTIVE

To investigate whether the risk for autoimmune diabetes in adults differs between socioeconomic groups and to compare such risk with that for type 2 diabetes.

RESEARCH DESIGN AND METHODS

The inhabitants of the Norwegian county of Nord-Trøndelag were investigated by questionnaires and clinical examinations on three occasions during 1984-2008. We used information from a subset consisting of 56,296 subjects (participating in at least two surveys), including 122 incident cases of autoimmune diabetes in adults (aged ≥35 and anti-GAD positive) and 1,555 cases of type 2 diabetes (aged ≥35 and anti-GAD negative). Hazard ratios (HRs) of diabetes associated with self-reported education and occupation were estimated by Cox proportional hazards models.

RESULTS

High levels of education (university versus primary school) were associated with an increased risk of autoimmune diabetes (HR 1.98 [95% CI 1.21-3.26]), after adjustment for BMI, lifestyle factors, and family history of diabetes. Case subjects with high levels of education had lower levels of C-peptide, tended to have higher levels of anti-GAD, and were more often treated with insulin. Conversely, these subjects had a reduced risk of type 2 diabetes (HR 0.69 [95% CI 0.57-0.82]), a risk that was partly explained by lower BMI and more physical activity (adjusted HR 0.89 [95% CI 0.74-1.06]).

CONCLUSIONS

High levels of education are associated with an increased risk of autoimmune diabetes in adults, a finding that may be mediated by effects on autoimmune activity. Because the association is not explained by traditional risk factors, other, currently unidentified, environmental factors are likely to be involved.

Environmental factors associated with childhood-onset type 1 diabetes mellitus: an exploration of the hygiene and overload hypotheses

OBJECTIVE

To assess the relationship between selected maternal and infant characteristics and risk of type 1 diabetes mellitus, specifically characteristics identified from birth records that may pertain to the hygiene or overload hypotheses.

DESIGN

Population-based case-control study.

SETTING

Washington State from 1987 to 2005.

PARTICIPANTS

All children younger than 19 years hospitalized for type 1 diabetes (International Classification of Diseases, Ninth Revision codes 250.x1 and 250.x3) identified (n=1852) from hospital discharge data and linked with their birth certificates. Controls (n=7408) were randomly selected from birth records, frequency matched on year of birth.

MAIN EXPOSURES

Maternal factors included age, race, educational attainment, marital status, use of Medicaid insurance, body mass index, prepregnancy weight, prior births, timing and adequacy of prenatal care, and cesarean delivery. Infant factors included birth weight, size for gestational age, and gestational age.

MAIN OUTCOME MEASURE

The main outcome was first hospitalization for type 1 diabetes mellitus; adjusted odds ratios were estimated for the association of selected maternal and infant characteristics with type 1 diabetes.

RESULTS

Consistent with the hygiene hypothesis, type 1 diabetes was negatively associated with having older siblings (for >or=3 siblings, odds ratio [OR], 0.56; 95% confidence interval [CI], 0.45-0.70) and with indicators of lower economic status or care access, such as an unmarried mother (OR, 0.79; 95% CI, 0.69-0.91), inadequate prenatal care (OR, 0.53; 95% CI, 0.40-0.71), or Medicaid insurance (OR, 0.67; 95% CI, 0.58-0.77). Related to the overload hypothesis, maternal body mass index of 30 or higher (OR, 1.29; 95% CI, 1.01-1.64) was associated with increased risk of diabetes.

CONCLUSION

Environmental factors related to decreased antigenic stimulation in early life and maternal obesity may be associated with type 1 diabetes.

Neighborhood socioeconomic change and diabetes risk: findings from the Chicago childhood diabetes registry

OBJECTIVE

To examine whether patterns in socioeconomic characteristics in Chicago over a 30-year period are associated with neighborhood distribution of youth diabetes risk.

RESEARCH DESIGN AND METHODS

Incident cases of diabetes in youth aged 0-17 years were identified from the Chicago Childhood Diabetes Registry between 1994 and 2003. Those with a type 2 diabetes-like clinical course or related indicators were classified as non-type 1 diabetic; the remaining cases were considered to have type 1 diabetes.

RESULTS

Compared with stable diversity neighborhoods, significant associations for type 1 diabetes were found for younger children residing in emerging low-income neighborhoods (relative risk 0.56 [95% CI 0.36-0.90]) and older children residing in emerging high-income neighborhoods (1.52 [1.17-1.98]). For non-type 1 diabetes, older youth residing in desertification neighborhoods were at increased risk (1.47 [1.09-1.99]).

CONCLUSIONS

Neighborhood socioeconomic characteristics in Chicago may be associated with the risk of diabetes in youth.

Epidemiology of type 1 diabetes among Silesian children aged 0-14 years, 1989-2005

The aim of this study was to estimate the present Polish incidence rate of diabetes mellitus type 1 in children aged 0-14. The research was conducted between 1989 and 2005 among the children of Upper Silesia region (Poland), being the part of the EURODIAB program, according to all criteria of this project. During this period, 1,385 new cases (720 boys) of diabetes mellitus type 1 were recognized. The analysis of the standardized incidence rates performed after dividing into shorter periods (1989-1994, 1995-1999, 2000-2005) showed a sharp increase from 5.80/10(5)/year through 9.54/10(5)/year to 15.26/10(5)/year, respectively, in the periods. Analysis of age subgroups showed the greatest increase in the incidence rate among the younger children: 3.59 times for children aged 0-4, 3.40 times for children aged 5-9 and 2.08 times for children aged 10-14. No significant difference of incidence rate between boys and girls was established. Such high increase of incidence rate of diabetes mellitus type 1 (above 260%) noted since 1989 shows a secular trend of an epidemic of diabetes mellitus type 1 in Poland and a conversion from countries with the lower incidence rates in Europe to the countries with the highest incidence rates.

The geoepidemiology of type 1 diabetes

Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by absolute insulin deficiency resulting from the progressive immune-mediated destruction of pancreatic islet beta cells. It is thought to be triggered by as yet unidentified environmental factors in genetically susceptible individuals, the major genetic contribution coming from loci within the HLA complex, in particular HLA class II. The worldwide incidence of T1D varies by at least 100-fold, being highest in Finland and Sardinia (Italy) and lowest in Venezuela and China. The incidence has been increasing worldwide at an annual rate of approximately 3%. While genetic factors are thought to explain some of the geographic variability in T1D occurrence, they cannot account for its rapidly increasing frequency. Instead, the declining proportion of newly diagnosed children with high-risk genotypes suggests that environmental pressures are now able to trigger T1D in genotypes that previously would not have developed the disease during childhood. Although comparisons between countries and regions with low and high-incidence rates have suggested that higher socioeconomic status and degree of urbanization are among the environmental factors that play a role in the rising incidence of T1D, the findings are too inconsistent to allow firm conclusions. Morbidity and mortality as well as causes of death also show considerable geographic variation. While glycemic control has been identified as a major predictor of the micro- and macrovascular complications of T1D and shows considerable geographical variability, it does not appear to be the only factor involved in the regional differences in complication rates. The role of genetics in susceptibility to nephropathy, retinopathy and other diabetic complications largely remains to be explored.

Prevalence of allergic symptoms among children with diabetes mellitus type 1 of different socioeconomic status

The aim of the study was to assess the possible associations between allergies and type 1 diabetes mellitus (DM1), stratified by social class. We studied 127 children with DM1 with a median age of 10.8 yr and 150 controls of comparable age and sex distribution. The parents completed questionnaires on their education and occupation and on their children's history of allergic symptoms, breast-feeding, viral infections, and measles-mumps-rubella (MMR) vaccination. Lower family's social class was more frequently encountered among the DM1 families than in the controls (OR = 0.56, 95% CI: 0.35-0.92). The occurrence of any allergic symptoms among children with DM1 (35.45%) was not significantly different from the controls (38.78%), neither in the total group (OR = 0.87, 95% CI: 0.52-1.45) nor in the stratified analysis by social class. Similar findings were observed regarding the different types of allergic symptoms. In the univariate analysis, breast-feeding, the experience of viral infections, and MMR vaccination were found to be protective of DM1 presentation in both upper and lower social classes. In the multiple logistic regression analysis, the experience of more than 2 infections/yr (OR = 0.12, 95% CI: 0.04-0.34), the origin from middle and upper social classes (OR = 0.42, 95% CI: 0.22-0.80) and breast-feeding (OR = 0.58, 95% CI: 0.31-1.07) were protective of DM1 occurrence. In children with DM1, the presence of allergic symptoms was not associated with the development of DM1. Among the environmental factors, the origin from middle or upper social classes, breast-feeding, the experience of viral infections, and MMR vaccination were found to have a protective effect on DM1 presentation.

Does social-economical transformation influence the incidence of type 1 diabetes mellitus? A Polish example

BACKGROUND

The dramatic increase in the incidence of diabetes mellitus type 1 (DMT1) in all countries of Central and Eastern Europe seems to be correlated with the rapid transformations of the political, economical, and social conditions. The aim of this study was to analyze the increase of DMT1 incidence vs. changes of parameters describing economical conditions, medical care standards, and level of hygiene.

MATERIALS AND METHODS

The study was based on the Upper Silesia, Poland, prospective register of DMT1 cases, a part of the EURODIAB program. The analyzed parameters were number of salmonellosis, taeniasis, diarrhea, and diarrhea in children aged 0 - 2 yr, alimentary toxicosis, neonatal mortality rate, average male and female life expectancy, gross domestic product (GDP), and accessibility to the water supply and sewage lines.

RESULTS

The dynamics of incidence increase has been very high: from 4.71/100 000 (1989) to 15.20/100 000 (2002); average increase per year is 7.52%. The statistically significant positive associations between DMT1 incidence and average male and female life expectancy, GDP, and accessibility of the water supply and sewage systems as well as the negative association for both neonatal mortality rate and nursery attendance were observed. No significant correlation was found between DMT1 and incidence rates of chosen diseases.

CONCLUSIONS

Currently, Poland and its part, Upper Silesia, belong to regions with high DMT1 incidence in children. The change from low to high incidence of DMT1 over the past 14 yr corresponded to profound social and economical transformations. Our observations confirm the importance of environmental factors in the aetiopathogenesis of DMT1. The state of hygiene and the state of the health of the society influence its susceptibility to DMT1.

Changing geographical distribution of diabetes mellitus type 1 incidence in Austrian children 1989--2005

OBJECTIVES

We investigated whether the significant spatial West/East trend of incidence of Diabetes mellitus Type 1 in Austrian children changed between 1989 and 2005. Additionally we tested, whether population density and mean body mass index of newborns is associated with incidence.

STUDY DESIGN AND SETTING

All newly diagnosed cases aged 0-14 years in Austria (n = 2644), prospectively registered from 1989 to 2005 were allocated to 99 districts. Ecological regression and analysis was done by Bayesian hierarchical models including spatially correlated risks.

RESULTS

In Austria, the incidence rose from 9.1/100.000 in 1989--1994 to 14.9/100.000 in 2001--2005. The spatial trend in the period 1989--1995, showing high incidence in the Eastern parts of Austria, disappeared. In the period 2001--2005 a significant inverse negative association of population density with incidence was found. Mean body mass index of newborns in the Austrian population is significantly positively associated with incidence.

CONCLUSION

The observation of higher incidence in rural areas in Austria during recent years may reflect a lower exposure to protective environmental factors, e.g. infections early in life. The observed association with the BMI in newborns indicates that neonatal or prenatal metabolic aspects may modulate the risk for childhood diabetes. We cannot explain the change in the spatial distribution of incidence.

Perinatal risk factors for childhood Type 1 diabetes in Western Australia--a population-based study (1980-2002)

AIMS

To investigate perinatal risk factors for childhood Type 1 diabetes in Western Australia, using a complete population-based cohort.

METHODS

Children born between 1980 and 2002 and diagnosed with Type 1 diabetes aged < 15 years (n = 940) up to 31 December 2003 were identified using a prospective population-based diabetes register with a case ascertainment rate of 99.8%. Perinatal data were obtained for all live births in Western Australia from 1980 to 2002 (n = 558 633) and record linkage performed to identify the records of cases.

RESULTS

The incidence of Type 1 diabetes increased by 13% for each 5-year increase in maternal age [adjusted incidence rate ratio (IRR) 1.13, 95% confidence interval (CI) 1.05, 1.21], by 13% for every 500-g increase in birth weight (adjusted IRR 1.13, 95% CI 1.04, 1.23). The incidence decreased with increasing birth order (adjusted IRR 0.89, 95% CI 0.82, 0.96) and increasing gestational age (adjusted IRR 0.84, 95% CI 0.77, 0.93). A higher incidence of Type 1 diabetes was associated with an urban vs. non-urban maternal address at the time of birth (adjusted IRR 1.38, 95% CI 1.18, 1.63), but no association was found with socio-economic status of the area.

CONCLUSIONS

A higher incidence of Type 1 diabetes was associated with increasing maternal age, higher birth weight, lower gestational age, lower birth order and urban place of residence at the time of birth.

The relationship between ACE genotype and risk of severe hypoglycaemia in a large population-based cohort of children and adolescents with type 1 diabetes

AIMS/HYPOTHESIS

Genetic factors may account for familial clustering related to diabetes complications. Studies have shown a significant relationship between the presence of the deletion (D) allele of the gene encoding ACE and risk of severe hypoglycaemia. This large prospective cohort study assesses this relationship in a large sample of children and adolescents with type 1 diabetes.

SUBJECTS AND METHODS

We studied 585 children and adolescents (mean age 11.9 +/- 4 years, 48.4% males). The frequency of severe hypoglycaemia (an event leading to loss of consciousness or seizure) was prospectively assessed over the 13-year period 1992-2004. Patients were seen with their parents every 3 months and data recorded at each visit. The ACE gene was detected using PCR.

RESULTS

In our cohort of 585 children, 186 (31.8%) had at least one episode of severe hypoglycaemia, and of these 28.0% had the II genotype, 48.9% had the ID genotype and 23.1% had the DD genotype. This was in agreement with the Hardy-Weinberg proportion. A total of 477 severe hypoglycaemic episodes was recorded with a total of 3,404 person-years of follow-up, giving a total incidence of 14 per 100 patient-years. No significant increase in risk for DD genotype (incidence rate ratio = 0.97, 95% CI 0.61-1.55) relative to II genotype was observed.

CONCLUSIONS/INTERPRETATION

This large prospective study concludes that the presence of the D allele of the ACE gene does not predict a significantly higher risk of severe hypoglycaemia in type 1 diabetic children and adolescents.

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

OBJECTIVES

The objectives of the study were to (i) determine the incidence of type 1 diabetes mellitus (T1DM) in children aged <15 yr in Victoria, Australia, from 1999 to 2002 and (ii) to analyze trends in incidence over this period.

METHODS

Prospective population-based incidence study. The primary source of case ascertainment was from the Australasian Paediatric Endocrine Group (APEG) Victorian diabetes register. The secondary source was the National Diabetes Register (NDR), which ascertains cases from the National Diabetes Service Scheme (NDSS), a Commonwealth government initiative, where patients register to receive diabetes supplies at a subsidized price.

MAIN OUTCOME MEASURES

Age-standardized incidence, trends in incidence by age, sex and year, and variation in incidence by region, season, and socioeconomic status.

RESULTS

Case ascertainment was 99.1% complete using the capture-recapture method. The mean annual age-standardized incidence was 19.3 per 100 000 person years from 1999 to 2002. On average, incidence increased by 9.3% per year, with a greater relative increase in the 0-4 yr age-group (p = 0.037). No gender bias in incidence was found, but the increase in females was statistically significant (13.6% per year, 95% confidence interval 3.7-24.3). Variation in geographical distribution and seasonal onset of incidence was not statistically significant.

CONCLUSIONS

The marked increase in the incidence of T1DM in Victoria is greater than that recently described in other Australia states and developed nations. The etiology of this rise is unclear, while the increased caseload has major implications for diabetes health care providers for current and future resource allocation.

Higher incidence of childhood-onset type 1 diabetes mellitus in remote areas: a UK regional small-area analysis

AIMS/HYPOTHESIS

We investigated the association between the incidence of type 1 diabetes mellitus and remoteness (a proxy measure for exposure to infections) using recently developed techniques for statistical analysis of small-area data.

SUBJECTS, MATERIALS AND METHODS

New cases in children aged 0 to 14 years in Northern Ireland were prospectively registered from 1989 to 2003. Ecological analysis was conducted using small geographical units (582 electoral wards) and area characteristics including remoteness, deprivation and child population density. Analysis was conducted using Poisson regression models and Bayesian hierarchical models to allow for spatially correlated risks that were potentially caused by unmeasured explanatory variables.

RESULTS

In Northern Ireland between 1989 and 2003, there were 1,433 new cases of type 1 diabetes, giving a directly standardised incidence rate of 24.7 per 100,000 person-years. Areas in the most remote fifth of all areas had a significantly (p=0.0006) higher incidence of type 1 diabetes mellitus (incidence rate ratio=1.27 [95% CI 1.07, 1.50]) than those in the most accessible fifth of all areas. There was also a higher incidence rate in areas that were less deprived (p<0.0001) and less densely populated (p=0.002). After adjustment for deprivation and additional adjustment for child population density the association between diabetes and remoteness remained significant (p=0.01 and p=0.03, respectively).

CONCLUSIONS/INTERPRETATION

In Northern Ireland, there is evidence that remote areas experience higher rates of type 1 diabetes mellitus. This could reflect a reduced or delayed exposure to infections, particularly early in life, in these areas.