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

Height growth velocity, islet autoimmunity and type 1 diabetes development: the Diabetes Autoimmunity Study in the Young

AIMS/HYPOTHESIS

Larger childhood body size and rapid growth have been associated with increased type 1 diabetes risk. We analysed height, weight, BMI and velocities of growth in height, weight and BMI, for association with development of islet autoimmunity (IA) and type 1 diabetes.

METHODS

Since 1993, the Diabetes Autoimmunity Study in the Young (DAISY) has followed children at increased type 1 diabetes risk, based on HLA-DR, -DQ genotype or family history, for the development of IA and type 1 diabetes. IA was defined as the presence of autoantibodies to insulin, GAD or protein tyrosine phosphatase islet antigen 2 twice in succession, or autoantibody-positive on one visit and diabetic at the next consecutive visit within 1 year. Type 1 diabetes was diagnosed by a physician. Height and weight were collected starting at age 2 years. Of 1,714 DAISY children <11.5 years of age, 143 developed IA and 21 progressed to type 1 diabetes. We conducted Cox proportional hazards analysis to explore growth velocities and size measures for association with IA and type 1 diabetes development.

RESULTS

Greater height growth velocity was associated with IA development (HR 1.63, 95% CI 1.31-2.05) and type 1 diabetes development (HR 3.34, 95% CI 1.73-6.42) for a 1 SD difference in velocity.

CONCLUSIONS/INTERPRETATION

Our study suggests that greater height growth velocity may be involved in the progression from genetic susceptibility to autoimmunity and then to type 1 diabetes in pre-pubertal children.

Maximising engagement, motivation and long term change in a Structured Intensive Education Programme in Diabetes for children, young people and their families: Child and Adolescent Structured Competencies Approach to Diabetes Education (CASCADE)

Background

This trial aims to evaluate effective delivery and cost effectiveness of an innovative structured psycho-educational programme (CASCADE) for young people and their families living with diabetes. The increase in numbers of people being diagnosed with diabetes is posing a challenge for both the UK and the rest of the world. The peak age for diagnosis is between 10 and 14 years of age. There is clear evidence that improved diabetes control from diagnosis in childhood can reduce the incidence and progression of long-term complications. However, despite the development of improved insulin regimens and delivery methods, the overall metabolic control in children and adolescents has improved little in the UK in the past decade. Therefore there is a need for novel interventions and health delivery mechanisms aimed at young people and their families to help improve control and reduce complications, illness burden and costs to the NHS.

Methods/Design

The CASCADE trial is a multi-centre randomised control trial with 26 clinics randomised to control or intervention groups, with 572 children and young people involved in the study. The intervention will be delivered in 4 group sessions, over a 4 month period. A developmentally appropriate curriculum will be delivered to groups of 3 - 4 families, focusing on achievement of increasing competency in self-management of diabetes. The control group will receive standard care from their clinical team, usually consisting of regular 3-monthly clinic visits and telephone contact as required with the clinical nurse specialist and consultant. The primary outcomes of the trial will be change in HbA1c between baseline and 12 months and 24 months post recruitment. Secondary outcomes will include measures related to the economic evaluation, psychosocial outcomes, outcomes related to management of diabetes outcomes, and adherence to the intervention.

Discussion

The trial will be run by independent research and service delivery teams and supervised by a trial steering committee. A data monitoring and ethics committee has been put in place to monitor the trial and recommend stopping/continuation according to a Peto-Haybittle rule. The trial will be conducted according to the principles of MRC Good Clinical Practice (GCP) Guidelines and CTRU Phase III Trial Standard Operating procedures.

Trial Registration

Current Controlled Trials ISRCTN52537669

Bioartificial Organ Grafts: A View at the Beginning of the Third Millennium

An immunoisolated collection of cells, which communicate and exchange essential factors, co-stimulatory hormones, as well as providing immunoprotection and immunomodulation, can be prepared, given existing scientific and medical know-how, within two decades. These "Bioartificial Organ Grafts" have advantages relative to isolated cell therapies, including beta-cell encapsulation for diabetes treatment, and xenotransplantation, which has a de facto moratorium. This paper documents that the majority of the research for the bioartificial organ grafts has been concluded, with the remaining hurdles minimum in comparison. The use of co-encapsulation and the induction of local immune-privilege will provide a more sensitive humoral hormonal response and graft survival, without systemic immunosuppression. A call for the staged implementation of bioartificial organ grafts, based on the best available medical practice, materials, tissue and technology available, is advocated. The implementation of bioartificial organ grafts can begin within the next two years, based on allografts succeeded by genetically modified human tissue, without the need to pass through a xenograft stage.

Early exposure to germs modifies kidney damage and inflammation after experimental ischemia-reperfusion injury

Kidney ischemia-reperfusion injury (IRI) is, in part, mediated by immune and inflammatory factors. Since microbial stimuli are known to alter immune and inflammatory responses, we hypothesized that differences in perinatal microbial status would modify renal injury following IRI. We performed bilateral renal IRI on 6-wk-old germ-free and control mice and studied the effects on kidney lymphocyte trafficking, cytokines, function, and structure. Compared with control mice, normal kidneys of germ-free mice exhibited more NKT cells and lower IL-4 levels. Postischemia, more CD8 T cells trafficked into postischemic kidneys of germ-free mice compared with control mice. Renal structural injury and functional decline following IRI were more severe in germ-free mice compared with control mice. When germ-free mice were conventionalized with the addition of bacteria to their diet, the extent of renal injury after IRI became equivalent to age-matched control mice, with similar numbers and phenotypes of T cells and NKT cells, as well as cytokine expression in both normal kidneys and postischemic kidneys of conventionalized germ-free mice and age-matched control mice. Thus microbial stimuli influence the phenotype of renal lymphocytes and the expression of cytokines of normal kidneys and also modulate the outcome of IRI.

Intron 4 polymorphism of the endothelial nitric oxide synthase eNOS gene and early microangiopathy in type 1 diabetes

Nitric oxide (NO) is an endogenous vasodilator involved in inflammatory and autoimmune response, and in the pathophysiology of diabetic vascular disease. Endothelium-derived NO is formed from L-arginine by endothelial NO synthase (eNOS), and earlier studies have provided evidence for altered NO metabolism and impaired endothelial function in diabetes, probably due to polymorphisms in eNOS gene. In the present study we investigated the association of the eNOS gene intron 4 a/b VNTR polymorphism with diabetic microangiopathy in 61 young individuals with type 1 diabetes (T1D), 35 male and 26 female, aged 5.0-29.1 (mean 15.6) years, and followed up for 3.24-11.4 (mean 7.44) years. Ten patients (16.4%) had developed microalbuminuria, three hypertension and two retinopathy. Wild-type b/b homozygosity for eNOS gene intron 4 VNTR was found in 37 (60.7%) and a/b polymorphism in 24 (39.3%). No significant relationship was demonstrated between eNOS gene intron 4 polymorphisms and microalbuminuria, hypertension or retinopathy in these young individuals. Our findings suggest that a/b polymorphism of the intron 4 eNOS gene is not associated with early onset diabetic microangiopathy.

Incidence and time trend of type 1 and type 2 diabetes in Austrian children 1999-2007

OBJECTIVE

To analyze the time trend of the nationwide incidence of type 2 diabetes in children and adolescents < or = 15 years of age compared with type 1 diabetes between 1999 and 2007 in Austria.

STUDY DESIGN

In a prospective, population-based incidence study, all newly diagnosed patients with diabetes < or = 15 years of age were registered by the Austrian Diabetes Incidence Study Group. The Diabetes type was classified on the basis of clinical and laboratory findings according to ADA criteria. Time trends were estimated by linear regression models.

RESULTS

During the observation period, 1881 patients with type 1 diabetes and 34 patients with type 2 diabetes could be identified. Sixty-two percent of patients with type 2 diabetes were female, 56% had a positive family history for type 2 diabetes, and 74% presented with diabetes-specific symptoms. The incidence of type 1 diabetes in Austria increased from 12.0 to 18.4/100,000 (P < .001) and the incidence of type 2 diabetes remained stable below 0.6/100 000 (P = .706).

CONCLUSIONS

The incidence of type 2 diabetes in Austrian children is 10-fold lower than reported in other regions and did not increase over the last 8 years. During the same time period, a significant rise in the incidence of type 1 diabetes was observed.

Incidence trends for childhood type 1 diabetes in Europe during 1989-2003 and predicted new cases 2005-20: a multicentre prospective registration study

BACKGROUND

The incidence of type 1 diabetes in children younger than 15 years is increasing. Prediction of future incidence of this disease will enable adequate fund allocation for delivery of care to be planned. We aimed to establish 15-year incidence trends for childhood type 1 diabetes in European centres, and thereby predict the future burden of childhood diabetes in Europe.

METHODS

20 population-based EURODIAB registers in 17 countries registered 29 311 new cases of type 1 diabetes, diagnosed in children before their 15th birthday during a 15-year period, 1989-2003. Age-specific log linear rates of increase were estimated in five geographical regions, and used in conjunction with published incidence rates and population projections to predict numbers of new cases throughout Europe in 2005, 2010, 2015, and 2020.

FINDINGS

Ascertainment was better than 90% in most registers. All but two registers showed significant yearly increases in incidence, ranging from 0.6% to 9.3%. The overall annual increase was 3.9% (95% CI 3.6-4.2), and the increases in the age groups 0-4 years, 5-9 years, and 10-14 years were 5.4% (4.8-6.1), 4.3% (3.8-4.8), and 2.9% (2.5-3.3), respectively. The number of new cases in Europe in 2005 is estimated as 15 000, divided between the 0-4 year, 5-9 year, and 10-14 year age-groups in the ratio 24%, 35%, and 41%, respectively. In 2020, the predicted number of new cases is 24 400, with a doubling in numbers in children younger than 5 years and a more even distribution across age-groups than at present (29%, 37%, and 34%, respectively). Prevalence under age 15 years is predicted to rise from 94 000 in 2005, to 160 000 in 2020.

INTERPRETATION

If present trends continue, doubling of new cases of type 1 diabetes in European children younger than 5 years is predicted between 2005 and 2020, and prevalent cases younger than 15 years will rise by 70%. Adequate health-care resources to meet these children's needs should be made available.

FUNDING

European Community Concerted Action Program.

Genetics of type 1 diabetes and autoimmune thyroid disease

The search for the susceptibility alleles for the complex genetic conditions of type 1 diabetes and autoimmune thyroid diseases has gained momentum in recent years. Studies have revealed several novel disease susceptibility alleles of relevance to both conditions, which brings the total number of genetic variants contributing to type 1 diabetes to ten. Additional genetic loci remain to be discovered, particularly in the autoimmune thyroid diseases. In the future, the density and coverage of single nucleotide polymorphisms available for high throughput genotyping will improve, and detailed analysis of the role of copy number variants in these diseases will shed new light on the pathogenesis of these common endocrinopathies.

Long-term trends in the incidence of type 1 diabetes in Denmark: the seasonal variation changes over time

There is a worldwide increase of type 1 diabetes mellitus (T1DM). In 1996, the Danish population-based registry was initiated including all newly diagnosed children aged 0-15 yr. This is the report of incidence and seasonal variation for the first 10 yr of the registry. The data was analyzed using Poisson's regression analysis. A total of 2166 children with diabetes were diagnosed before the age of 15 yr between 1996 and 2005. In this period, the annual increase in childhood T1DM was 3.43% (95% confidence interval: 1.91-4.97), which was unaffected by age and gender. Seasonal variation in incidence rates varied by year but not by age and gender. In conclusion, there is a steep increase in incidence of childhood T1DM in Denmark; the increase is comparable with the increase seen in other European countries. There is a significant seasonal variation that changes on a year-to-year basis. The observed variations in cadence rates may be associated with viral epidemics, sunshine exposure, or vitamin D levels and suggest further exploration of these relations.

Interplay between PTPN22 C1858T polymorphism and cow's milk formula exposure in type 1 diabetes

Genetic heterogeneity may affect the analysis of risk factors associated with type 1 diabetes (T1D). We studied the effect of the INS -23A/T, PTPN22 1858C/T, and CTLA-4 +49A/G polymorphisms on the emergence of T1D-associated autoimmunity in children exposed to cow's milk (CM) based formula during early or late infancy. The study comprised of 156 children from the Finnish DIPP cohort who had developed >or= 2 types of autoantibodies (ICA, IAA, GADA or IA-2A) or clinical T1D and 563 control children. The PTPN22 1858T allele was associated with the appearance of the autoantibodies and clinical T1D among children exposed to CM formula before the age of 6 months (PTPN22: for all P <or= 0.001, Log Rank test), but not among children exposed later on. Cox regression analysis showed an interaction between early CM exposure and 1858T allele and enhanced appearance of ICA, IAA and IA-2A (for all P <or= 0.04). Our results imply that the PTPN22 polymorphism affects the development of T1D-associated autoimmunity only if children are exposed to CM formula during early infancy suggesting an interplay between genetic and environmental factors. This may provide an explanation for the contradictory findings on the significance of CM formula exposure in T1D.

Genome-wide association studies in type 1 diabetes

Type 1 diabetes (T1D) is a chronic disease that typically manifests itself in childhood through the autoimmune destruction of pancreatic beta cells, resulting in a lack of production of insulin. T1D is a multifactorial disease with a strong genetic component that is thought to interact with specific environmental triggers. Several genetic determinants of T1D were already established before the era of genome-wide association studies, primarily with the HLA class II genes, encoding highly polymorphic antigen-presenting proteins that account for almost 50% of the genetic risk for T1D. The recent development of high-throughput single nucleotide polymorphism genotyping array technologies has enabled investigators to perform high-density genome-wide association studies in search of the remaining T1D loci. Combined with the well-established genes known for many years, 16 loci have now been uncovered to date as being robustly associated with the pathogenesis of this phenotype.

Type 1 diabetes in the BB rat: a polygenic disease

OBJECTIVE

Two type 1 diabetes susceptibility genes have been identified in the spontaneously diabetic biobreeding diabetes-prone (BBDP) rat, the major histocompatibility complex (MHC) (RT1) class II u haplotype (Iddm1) and Gimap5 (Iddm2). The strong effects of these have impeded previous efforts to map additional loci. We tested the hypothesis that type 1 diabetes is a polygenic disease in the BBDP rat.

RESEARCH DESIGN AND METHODS

We performed the most comprehensive genome-wide linkage analysis for type 1 diabetes, age of disease onset (AOO), and insulitis subphenotypes in 574 F2 animals from a cross-intercross between BBDP and type 1 diabetes-resistant, double congenic ACI.BBDP-RT1u,Gimap5 (ACI.BB(1u.lyp)) rats, where both Iddm1 and Iddm2 were fixed as BBDP.

RESULTS

A total of 19% of these F2 animals developed type 1 diabetes, and eight type 1 diabetes susceptibility loci were mapped, six showing significant linkage (chromosomes 1, 3, 6 [two loci], 12, and 14) and two (chromosomes 2 and 17) suggestive linkage. The chromosomes 6, 12, and 14 intervals were also linked to the severity of islet infiltration by immunocytes, while those on chromosomes 1, 6 (two loci), 14, 17, and a type 1 diabetes-unlinked chromosome 8 interval showed significant linkage to the degree of islet atrophy. Four loci exhibited suggestive linkage to AOO on chromosomes 2 (two loci), 7, and 18 but were unlinked to type 1 diabetes. INS, PTPN22, IL2/IL21, C1QTNF6, and C12orf30, associated with human type 1 diabetes, are contained within the chromosomes 1, 2, 7, and 12 loci.

CONCLUSIONS

This study demonstrates that the BBDP diabetic syndrome is a complex, polygenic disease that may share additional susceptibility genes besides MHC class II with human type 1 diabetes.

Variations in incidence of type 1 diabetes in different municipalities of stockholm

This article reports a test of the hypothesis that municipalities within the County of Stockholm have varying incidence rates of type 1 diabetes (T1D), suggesting a strong etiologic environmental component to the disease. The study group included T1D patients in the age group from birth to 18 years who were diagnosed each year from 20 municipalities in Stockholm County during the 1990-2003. Specific incidence rates by age, sex, and socioeconomic characteristics (income level, proportion of taxpayers, proportion of foreigners, population density and green cover) were estimated annually together with age standardization. chi(2) analyses were used for the statistical assessment of variability in incidence. During the study period, 733 newly diagnosed T1D patients aged 0-18 years were recorded from the 20 municipalities under study. The overall age-standardized incidence in these 20 municipalities was 24.38 (22.65-26.21) per 100,000, with 45.35 (32.08-62.29) as highest and 13.41 (9.53-18.35) as lowest estimated incidence. For all socioeconomic variables statistically significant heterogeneity was demonstrated in the standardized incidence rate. High green index was positively associated with the incidence of T1D, as was low population density. For the three remaining socioeconomic variables no clear patterns of associations with incidence of T1D were seen. This study demonstrates a considerable and statistically significant variation between the lowest and highest values in the incidence and prevalence rates for T1D in municipalities of Stockholm County. Such variation seems unlikely to be explained by genetic differences since the population is homogeneous. Our study provides support for the hypothesis that environmental factors have a major influence on the pathogenesis of T1D.

Special needs of children with type 1 diabetes at primary school: perceptions from parents, children, and teachers

OBJECTIVE

To identify the special needs of children with type 1 diabetes at primary school taking into account the perceptions reported by parents, children, and teachers.

METHODS

This was a cross-sectional survey carried out at nine public hospitals with a cohort of 6- to 13-yr-old children. Parents were personally informed about the objectives of the survey and the necessity to involve their children and the teachers. The self-reporting questionnaire included demographic information as well as some questions that helped to evaluate the general situation of children with type 1 diabetes at primary school, main worries about the disease, and possible improvement measures.

RESULTS

A total of 430 questionnaires were completed and validated of which 39% were filled in by parents, 35% by children, and 26% by teachers. The majority of children were 10-13 yr old and came from public schools. At school, most children required glucose monitoring, but few of them (9-12%) needed insulin administration. Some parents (7%) experienced problems at their schools when they informed them about their children's disease, 2% were finally not accepted, and 1% were forced to change school. Major children's concerns included the ability to recognize hypoglycemia or to self-administer insulin. Parents, teachers, and children demanded better information at school about diabetes and about emergency management.

CONCLUSIONS

The three population groups agreed about the necessity of having more available information on diabetes at schools. Although some discriminatory behavior was still occurring, it seemed it has been diminishing in recent years.

Epidemiology of type 1 diabetes and what animal models teach us about the role of viruses in disease mechanisms

There is a consensus among epidemiologists that the worldwide incidence rate of type 1 diabetes has been rising in recent decades. The cause of this rise is unknown, but epidemiological studies suggest the involvement of environmental factors, and viral infections in particular. Data demonstrating a cause-and-effect relationship between microbial infections and type 1 diabetes and how viruses may cause disease in humans are currently lacking. However, new evidence from animal models supports the hypothesis that viruses induce disease via mechanisms linked with innate immune upregulation. In the BioBreeding Diabetes Resistant rat, infection with a parvovirus induces islet destruction via upregulation of the toll-like receptor 9 (TLR9) signaling pathway. Data from mouse models of diabetes implicate TLR2, TLR3, and TLR7 in the disease process. Understanding the link between environmental agents and innate immune pathways involved in early stages of diabetes may advance the design of immune interventions to prevent disease in genetically susceptible individuals.

[Controversies in the association between type 1 diabetes and asthma]

OBJECTIVE

Critical review of the literature to investigate the relationship between asthma and type 1 diabetes mellitus (DM1).

SOURCE OF DATA

Bibliography search in MEDLINE and LILACS databases in the last twenty years.

SUMMARY OF DATA

Several studies demonstrate an inverse relationship between asthma, atopic diseases and the risk to develop DM1. According to the "Hygiene Hypothesis", the risk of allergic diseases decreases with infections early in childhood, towards distance of Th2 profile, common at birth, to the Th1 phenotype. Other articles described lack of association or positive association between DM1 and allergies. There is a possibility of environmental factors interfering in the development of disorders mediated by Th1 and Th2 cells, in the same individual, due to the absence of immunomodulatory mechanisms mediated by interleukin-10 and regulatory cells.

CONCLUSION

The existing information about the inverse association between Th1-mediated diseases (e.g., DM1), and those that are Th2-mediated (e.g., allergies) are conflicting requiring more investigation to explain this question.

Seasonal variance of 25-(OH) vitamin D in the general population of Estonia, a Northern European country

BACKGROUND

Vitamin D has a wide variety of physiological functions in the human body. There is increasing evidence that low serum levels of this vitamin have an important role in the pathogenesis of different skeletal and extra-skeletal diseases. Vitamin D deficiency and insufficiency is common at northern latitudes. There are few population-based studies in the northern European region looking at the issue in a wider age group. We aimed to measure Vitamin D level in the general population of Estonia (latitude 59 degrees N), a North-European country where dairy products are not fortified with vitamin D.

METHODS

The study subjects were a population-based random selection of 367 individuals (200 women and 167 men, mean age 48.9 +/- 12.2 years, range 25-70 years) from the registers of general health care providers. 25-(OH) vitamin D (25(OH)D) level and parathyroid hormone (PTH) were measured in summer and in winter. Additionally age, sex, body mass index (BMI) and self-reported sunbathing habits were recorded.

RESULTS

The mean serum 25(OH)D concentration in winter was 43.7 +/- 15 nmol/L and in summer 59.3 +/- 18 nmol/L (p < 0.0001). In winter 73% of the subjects had 25(OH)D insufficiency (25(OH)D concentration below 50 nmol/L) and 8% had deficiency (25(OH)D below 25 nmol/L). The corresponding percentages in summer were 29% for insufficiency and less than 1% for deficiency. PTH reached a plateau at around 80 nmol/L. BMI and age were inversely associated with 25(OH)D, but lost significance when adjusted for sunbathing habits. A difference in the seasonal 25(OH)D amplitude between genders (p = 0.01) was revealed.

CONCLUSION

Vitamin D insufficiency is highly prevalent throughout the year in a population without vitamin D dairy fortification living at the latitude of 59 degrees N.

A TLR2 polymorphism is associated with type 1 diabetes and allergic asthma

Type 1 diabetes (T1D) and allergic asthma are immune-mediated diseases. Pattern recognition receptors are proteins expressed by cells in the immune system to identify microbial pathogens and endogenous ligands. Toll-like receptors (TLRs) and CD14 are members of this family and could represent a molecular link between microbial infections and immune-mediated diseases. Diverging hypotheses regarding whether there exists a common or inverse genetic etiology behind these immune-mediated diseases have been presented. We aimed to test whether there exist common or inverse associations between polymorphisms in the pattern recognition receptors TLR2, TLR4 and CD14 and T1D and allergic asthma. Eighteen single nucleotide polymorphisms (SNPs) were genotyped in TLR2 (2), TLR4 (12) and CD14 (4) in 700 T1D children, 357 nuclear families with T1D children and 796 children from the 'Environment and Childhood Asthma' study. Allele and haplotype frequencies were analyzed in relation to diseases and in addition transmission disequilibrium test analyses were performed in the family material. Both T1D and allergic asthma were significantly associated with the TLR2 rs3804100 T allele and further associated with the haplotype including this SNP, possibly representing a susceptibility locus common for the two diseases. Neither TLR4 nor CD14 were associated with T1D or allergic asthma.

Testicular mitochondrial alterations in untreated streptozotocin-induced diabetic rats

Diabetes-induced complications are associated with mitochondrial dysfunction and increasing evidence suggests that diabetes has an adverse effect on male reproductive function. The STZ-induced diabetic rat was used as an animal model for the type 1 form of the disease with the aim of determining its effects in spermatogenesis and testicular mitochondrial function. Several aspects of mitochondrial function were measured, including respiratory and electric potential function, as well as mitochondrial calcium loading capacity. Additionally oxidative stress production, antioxidant levels and possible apoptotic alterations were also evaluated. We observed that diabetic animals present alterations in spermatogenesis in both the testis and epidydimus. However, and surprisingly, the overall results in mitochondrial parameters failed to reveal severe testicular mitochondrial dysfunction in diabetic animals, with the exception of a decrease in calcium load. Taken together, results suggest that in animal models that mimic untreated type 1 diabetes the severe effects of the condition on spermatogenesis are not directly mitochondrial-mediated.

Tobacco exposure and diabetes-related autoantibodies in children: results from the ABIS study

Passive smoking has decreased in recent years ("increased hygiene"). Less environmental tobacco smoke (ETS) gives increased hygiene that, if the hygiene hypothesis is true, in turn might give more autoimmune diseases. The presence of auto antibodies is considered to be an early indicator of type 1 diabetes (T1D). Because tobacco exposure may influence the immune system, we analyzed the relation between passive smoking and development of autoantibodies. A subsample (n= 8794) of the children in the ABIS study was used for this analysis. The parents answered questionnaires on smoking from pregnancy and onwards, and blood samples from the children aged 2.5-3 years were analyzed for GADA and IA-2A. Results showed that there was no significant difference in the prevalence of GADA or IA-2A (>95 percentile) between tobacco-exposed and nonexposed children. It was concluded that passive smoking does not seem to influence development of diabetes-related autoantibodies early in life.

Temporal trends of HLA genotype frequencies of type 1 diabetes patients in Sweden from 1986 to 2005 suggest altered risk

The aim of this study was to compare the frequency of human leukocyte antigen (HLA) genotypes in 1-18-year-old patients with type 1 diabetes newly diagnosed in 1986-1987 (n = 430), 1996-2000 (n = 342) and in 2003-2005 (n = 171). We tested the hypothesis that the HLA DQ genotype distribution changes over time. Swedish type 1 diabetes patients and controls were typed for HLA using polymerase chain reaction amplification and allele specific probes for DQ A1* and B1* alleles. The most common type 1 diabetes HLA DQA1*-B1*genotype 0501-0201/0301-0302 was 36% (153/430) in 1986-1987 and 37% (127/342) in 1996-2000, but decreased to 19% (33/171) in 2003-2005 (P \ 0.0001). The 0501-0201/0501-0201 genotype increased from 1% in 1986-1987 to 7% in 1996-2000 (P = 0.0047) and to 5% in 2003-2005 (P > 0.05). This study in 1-18-year-old Swedish type 1 diabetes patients supports the notion that there is a temporal change in HLA risk.

A coding polymorphism in NALP1 confers risk for autoimmune Addison's disease and type 1 diabetes

Variants in the gene encoding NACHT leucine-rich-repeat protein 1 (NALP1), an important molecule in innate immunity, have recently been shown to confer risk for vitiligo and associated autoimmunity. We hypothesized that sequence variants in this gene may be involved in susceptibility to a wider spectrum of autoimmune diseases. Investigating large patient cohorts from six different autoimmune diseases, that is autoimmune Addison's disease (n=333), type 1 diabetes (n=1086), multiple sclerosis (n=502), rheumatoid arthritis (n=945), systemic lupus erythematosus (n=156) and juvenile idiopathic arthritis (n=505), against 3273 healthy controls, we analyzed four single nucleotide polymorphisms (SNPs) in NALP1. The major allele of the coding SNP rs12150220 revealed significant association with autoimmune Addison's disease compared with controls (OR=1.25, 95% CI: 1.06-1.49, P=0.007), and with type 1 diabetes (OR=1.15, 95% CI: 1.04-1.27, P=0.005). Trends toward the same associations were seen in rheumatoid arthritis, systemic lupus erythematosus and, although less obvious, multiple sclerosis. Patients with juvenile idiopathic arthritis did not show association with NALP1 gene variants. The results indicate that NALP1 and the innate immune system may be implicated in the pathogenesis of many autoimmune disorders, particularly organ-specific autoimmune diseases.

Infectious diseases and Type 1 diabetes in children

Type 1 diabetes (T1D) is an autoimmune disease triggered by environmental factors. Among those of infectious origin, viruses mostly associated to T1D are rubella virus, enteroviruses (Rotavirus, Coxackie B), Cytomegalovirus and mumps virus. The role of bacterial infections is still controversial, acting either as modulators or precipitating factors of an already started autoimmune process. Polymorphic genes of innate immunity, such as Toll-like receptors, nucleotide-binding oligomerization domain (NOD) 1 and NOD2 and mannose-binding lectin (MBL) genes, did not show a strict association with T1D onset, while protein tyrosine phosphatase (PTPN22), cytotoxic T-lymphocyte antigen (CTLA)4 and natural killer cells immunoglobulin-like receptor (KIR) genes appear to play an important role. However, the adaptive immune response genes (HLA) still provide the major contribution to T1D susceptibility. Here, we review the mechanism by which microorganisms might induce autoimmunity.

Helminth infections associated with multiple sclerosis induce regulatory B cells

OBJECTIVE

To assess the importance of B-cell control during parasite infections in multiple sclerosis (MS) patients.

METHODS

Peripheral blood CD19+ B cells from 12 helminth-infected MS patients, 12 MS patients without infection, 10 patients infected with Trypanosoma cruzi, 8 subjects infected with Paracoccidioides brasiliensis, and 12 healthy control subjects were purified using magnetic cell sorting. Interleukin (IL)-4, IL-6, IL-10, tumor necrosis factor-alpha, lymphotoxin, transforming growth factor-beta, brain-derived neurotrophic factor, and nerve growth factor secretion were evaluated after stimulation with CDw32 L cells and CD40 antibody using enzyme-linked immunosorbent assays. The production of anti-myelin oligodendrocyte glycoprotein IgG and IgM antibodies was evaluated by enzyme-linked immunosorbent spot assays. Cell phenotype was assessed by flow cytometry.

RESULTS

Helminth infections in MS patients created a B-cell population producing high levels of IL-10, dampening harmful immune responses through a mechanism mediated, at least in part, by the ICOS-B7RP-1 pathway. The IL-10-producing B-cell phenotype detected expressed high levels of CD1d and was similar to the one observed in mature naive B2 cells (namely, CD11b(-), CD5(-), CD27(-), and IgD+). Moreover, B cells isolated from helminth-infected MS patients also produced greater amounts of brain-derived neurotrophic factor and nerve growth factor compared with those of normal subjects, T. cruzi-infected subjects, P. brasiliensis-infected subjects, or uninfected MS patients, raising the possibility that these cells may exert a neuroprotective effect on the central nervous system.

INTERPRETATION

Increased production of B-cell-derived IL-10 and of neurotrophic factors are part of the parasite's regulation of host immunity and can alter the course of MS, potentially explaining environmental-related MS suppression observed in areas with low disease prevalence.

Translational mini-review series on the immunogenetics of gut disease: immunogenetics of coeliac disease

Recent advances in immunological and genetic research in coeliac disease provide new and complementary insights into the immune response driving this chronic intestinal inflammatory disorder. Both approaches confirm the central importance of T cell-mediated immune responses to disease pathogenesis and have further begun to highlight other relevant components of the mucosal immune system, including innate immunity and the control of lymphocyte trafficking to the mucosa. In the last year, the first genome wide association study in celiac disease led to the identification of multiple new risk variants. These risk regions implicate genes involved in the immune system. Overlap with autoimmune diseases is striking with several of these regions being shown to confer susceptibility to other chronic immune-mediated diseases, particularly type 1 diabetes.

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.

Correlative and quantitative 1H NMR-based metabolomics reveals specific metabolic pathway disturbances in diabetic rats

Type 1 diabetes was induced in Sprague-Dawley rats using streptozotocin. Rat urine samples (8 diabetic and 10 control) were analyzed by 1H nuclear magnetic resonance (NMR) spectroscopy. The derived metabolites using univariate and multivariate statistical analysis were subjected to correlative analysis. Plasma metabolites were measured by a series of bioassays. A total of 17 urinary metabolites were identified in the 1H NMR spectra and the loadings plots after principal components analysis. Diabetic rats showed significantly increased levels of glucose (P < 0.00001), alanine (P < 0.0002), lactate (P < 0.05), ethanol (P < 0.05), acetate (P < 0.05), and fumarate (P < 0.05) compared with controls. Plasma assays showed higher amounts of glucose, urea, triglycerides, and thiobarbituric acid-reacting substances in diabetic rats. Striking differences in the Pearson's correlation of the 17 NMR-detected metabolites were observed between control and diabetic rats. Detailed analysis of the altered metabolite levels and their correlations indicate a significant disturbance in the glucose metabolism and tricarboxylic acid (TCA) cycle and a contribution from gut microbial metabolism. Specific perturbed metabolic pathways include the glucose-alanine and Cori cycles, the acetate switch, and choline metabolism. Detection of the altered metabolic pathways and bacterial metabolites using this correlative and quantitative NMR-based metabolomics approach should help to further the understanding of diabetes-related mechanisms.

Variation in associations between allelic variants of the vitamin D receptor gene and onset of type 1 diabetes mellitus by ambient winter ultraviolet radiation levels: a meta-regression analysis

Vitamin D receptor (VDR) gene polymorphisms may be associated with risk of developing type 1 diabetes mellitus (T1DM), but reports have been conflicting. The authors reexamined population-based case-control studies on selected VDR polymorphisms and T1DM to investigate whether variation in reported associations could be partly explained by differences in ambient winter ultraviolet radiation (UVR) levels. A meta-analysis of 16 studies from 19 regions (midwinter UVR range, 1.0-133.8 mW/m(2)) was conducted. The association between winter UVR and the log odds ratio was examined by meta-regression. For FokI and BsmI, the log odds ratio for the association between the F and B alleles and T1DM increased as regional winter UVR increased (p = 0.039 and p = 0.036, respectively). The association between the TaqI T allele and T1DM was reduced with increasing winter UVR (p = 0.040). Low winter regional UVR was associated with a higher proportion of controls carrying BsmI and ApaI uppercase alleles and a lower proportion of controls carrying TaqI uppercase alleles. These findings strengthen the case that VDR variants are involved in the etiology of T1DM. They suggest that environmental UVR may influence the association between VDR genotype and T1DM risk. Further work on VDR polymorphisms and T1DM should concomitantly examine the roles of past UVR exposure and vitamin D status.

Diabetes and osteoporosis

Care of patients with diabetes should include assessment of bone health. The extension of the average life expectancy of people with diabetes, which has accompanied improvements in medical care, has also increased the significance of osteoporosis. In addition to the usual causes of osteoporosis associated with aging, bone health is also compromised by diabetes. Studies on bone involvement in patients with diabetes mellitus have generated conflicting results, largely because of the pathogenetic complexity of the condition. It is now clear that patients with type 1 diabetes have lower bone mineral density (BMD) and a higher risk of fractures. Evidence is emerging that patients with type 2 diabetes who have complications are also at increased risk of certain types of osteoporotic fractures, despite having a higher BMD when compared to patients with type 1 diabetes. Although many factors, including number and type of falls, visual impairment, neuropathy, and reduced muscle strength, influence the probability of fractures, the most significant factor seems to be the strength of the bone itself. Thus, sarcopenia, a reduction in muscle mass and muscle strength, is considered one of the main determinants of bone fragility. The aim of this review is to examine the occurrence of osteoporosis in type 1 and type 2 diabetes.

Glycaemic control and diabetes care utilization in young adults with Type 1 diabetes

OBJECTIVES

To explore how glycaemic control in young adults is related to diabetes care utilization during the transition to adult diabetes care and if these variables differ between males and females.

METHODS

This is a retrospective, longitudinal design following patients' records from age 18-24 years. Adolescents (n = 104) connected to one paediatric outpatient clinic and referred to six different adult clinics were included. Data were collected regarding gender, age at diagnosis and transfer, yearly glycated haemoglobin (HbA(1c)) and body mass index, severe hypoglycaemia and diabetic ketoacidosis, retinopathy and diabetes care utilization.

RESULTS

HbA(1c) decreased over time in females (P = 0.004) but not in males. Less than 10% had HbA(1c) in the recommended range during the study period. The decrease in severe hypoglycaemia and diabetic ketoacidosis was not significant. The prevalence of background retinopathy increased from 5 to 29% during the study period (P < 0.001). Mean transfer age was 19.8 years. The youths visited the paediatric clinic more often than the adult clinic (P < 0.001) and females visited adult care more often than males (P = 0.04). There was a steady decrease in the number of visits/year over time (P < 0. 001). Poor glycaemic control was associated with more visits for both males and females (P = 0.005) in adult care.

CONCLUSIONS

As there was no gender difference in the relation between HbA(1c) and the number of visits in adult diabetes care, the higher frequency of visits in adult care for females cannot be solely explained by their glycaemic control. Gender differences regarding diabetes care utilization should be further explored.

Trends of type 1 diabetes in Karachi, Pakistan

OBJECTIVE

Our study aims to assess the presentation, prevalence, and associations of acute and chronic complications in subjects with type 1 diabetes mellitus (T1DM) at their first visit to outpatient departments.

STUDY DESIGN AND SETTING

Study was carried out at two centers, Diabetic Association of Pakistan and WHO Collaborating Centre and Baqai Institute of Diabetology and Endocrinology, Karachi. Records of 591 T1DM subjects divided into two groups were studied. Group 1 (62.1%, n = 367) includes patients with known T1DM and group 2 (n = 224, 37.9%), newly diagnosed T1DM. Clinical features [polyuria, polydipsia, polyphagia, history of weight loss, and history of diabetic ketoacidosis (DKA)] were recorded. Biochemical parameters including fasting plasma glucose, 2-h postprandial plasma glucose, hemoglobin A1c, urinary ketones, and proteinuria were recorded. Arterial blood gases was done in suspected cases of DKA.

RESULTS

In group 1, male predominance was seen (57.8 vs. 42.2%). Mean age at presentation was 19.1 +/- 10 yr. Mean duration of diabetes was 16 +/- 9 yr. Two percent subjects presented with DKA, while 21% had a history of DKA. Among the subjects with >10 yr of diabetes, 20.1% had hypertension, 5.5% had nephropathy, 2.9% had neuropathy, and 7.7% had retinopathy. In group 2, 224 T1DM subjects were identified, with mean age of 17 +/- 11 yr. Equal number of males (50.9%) and females (49.1%) were diagnosed at their first presentation. Most subjects (40.8%, n = 91) diagnosed between 11 and 20 yr of age presented with polyuria (81.3%), polydipsia (77.2%), polyphagia (56.7%), and weight loss (79.5%). Ketonuria was positive in 4.9%, while 5.8% presented with DKA.

CONCLUSIONS

This is the first study in Pakistan to assess the mode of presentation and prevalence of acute and chronic complications in T1DM. Larger scale prospective studies are needed to have more detailed informative data.

Attitudes to psychological groups in a paediatric and adolescent diabetes service--implications for service delivery

OBJECTIVE

To explore the potential interest in psychology support groups in a paediatric and adolescent diabetes service.

RESEARCH DESIGN AND METHODS

A short semi-structured interview using both open and closed questions to generate quantitative and qualitative data. Sixty-four parents were interviewed on the telephone by an assistant psychologist.

RESULTS

The majority of parents (81%) reported an interest in participating in a psychology group if it was offered, but preferences varied between a child/young person group (33%), parents only (15%) or family groups (11%). Twenty-three percent said that they would prefer individual work rather than a group. Parents identified groups as an opportunity to acquire practical knowledge, exchange ideas in an informal setting, share a common reality with others and gain more confidence in managing diabetes together with their child. Reasons not to attend a group included parents being able to cope well at the moment, school demands, feeling uncomfortable speaking in front of a group and use of online support groups.

CONCLUSION

The majority of parents identified psychological support as having a role for families living with diabetes. The audit highlighted that families have different ideas about how they would prefer this support to look and emphasized the need to consult with service users when designing psychological support for young people and families living with a chronic condition.

Students with chronic diseases: nature of school physician support

BACKGROUND

To educate children with chronic diseases in the least restrictive environment, schools must prevent, recognize, and react appropriately to symptom exacerbations. Schools are often pushed to their limits of knowledge, resources, and comfort level. This study determined the health conditions of students for whom districts seek school physician consultation and the nature of school physician consultants' involvement.

METHODS

A retrospective record review was performed on 250 of the most recent records of school-elicited referrals from an academic center that provides physician consultation to school districts. Referrals were sent from 8 school districts in southern California (July 1996 to October 2006). Data collected were nature of student's special health need, the school physician consultant's intervention required to satisfy schools' needs, student grade level, enrollment in special education, and health-related excessive absenteeism.

RESULTS

No single chronic condition, symptom, or special health care need predominated. Six types of school physician consultant activities were used to overcome hurdles schools faced when accommodating students with special health care needs. The 3 most common were direct communication with students' own physicians (70% of students), recommending an appropriate level of school health services when this was a matter of controversy (42%), and formulating portions of students' individualized school health plans (38%).

CONCLUSIONS

A portion of students with special health care needs benefited from district referral to a school physician consultant. Whether some of these referrals can be avoided if school personnel and students' own physicians are supported and trained to communicate more effectively with one another needs to be explored.

Very high and increasing incidence of type 1 diabetes mellitus in Newfoundland and Labrador, Canada

OBJECTIVE

To determine the incidence of type 1 diabetes mellitus (T1DM) among children aged 0-14 yr inclusive in the Canadian province of Newfoundland and Labrador (NL).

METHODS

Prospective and retrospective cohort study of the incidence of T1DM in children aged 0-14 yr from 1987 to 2005. Identified cases during this time period were ascertained from several sources and verified using the capture-recapture technique.

RESULTS

Over the study period, 732 children aged 0-14 yr were diagnosed with T1DM. The incidence of T1DM in this population over the period 1987-2005 inclusive was 35.08 per 100,000 (95% confidence interval: 32.54, 37.62). The incidence over this period increased linearly at the rate of 0.78 per 100 000 per year. There was a significant difference between the incidence of 31.61 per 100,000 for boys in the 0-4-yr age-group and 19.05 per 100,000 for girls in the 0-4-yr age-group (p = 0.001). The incidence was very high throughout the entire province.

CONCLUSIONS/INTERPRETATION

The province of NL has one of the highest incidences of T1DM reported worldwide. The incidence is increasing over the 19-yr study period.

Perinatal risk factors for early childhood onset type 1 diabetes in Austria - a population-based study (1989-2005)

BACKGROUND

To investigate the rapid increase in incidence of type 1 diabetes mellitus (T1DM) in children <5 yr in Austria.

METHODS

Data of children born between 1989 and 2005 (n = 444) from the T1DM children incidence registry were linked with birth certificates (n = 1 407 829).

RESULTS

Age of mother, level of education, birth weight, birth length, body mass index, and APGAR score at 10 min were not significant. Boys have about 25% higher risk than girls [hazard ratio = 0.75, 95% confidence interval (CI): 0.62-0.91]. The risk of developing diabetes increases over time significantly (1989-1991 vs. 2001-2005, hazard ratio = 2.86, 95% CI: 2.07-3.94). The linear effect of parity is borderline significant (p = 0.045), with lower risks for second and later born siblings. Marital status is significant [hazard ratio = 0.73, 95% CI: 0.57-0.90)]. Native-born children exhibit twice as high risk as non-native children (hazard ratio = 0.51, 95% CI: 0.37-0.71). Birth weight shows a positive but not significant effect on risk of T1DM.

CONCLUSIONS

In this very young and rapidly increasing cohort of diabetic children <5 yr of age, no association with birth weight but with year of birth, gestational age, nationality and parity could be observed.

Time trends in the incidence of type 1 diabetes in Finnish children: a cohort study

BACKGROUND

Finland has the highest incidence of type 1 diabetes worldwide, reaching 40 per 100,000 people per year in the 1990s. Our aim was to assess the temporal trend in type 1 diabetes incidence since 2000 in Finnish children aged younger than 15 years and to predict the number of cases of type 1 diabetes in the future.

METHODS

Children with newly diagnosed type 1 diabetes in Finland who were listed on the National Public Health Institute diabetes register, Central Drug Register, and Hospital Discharge Register in 1980-2005 were included in a cohort study. We excluded patients with type 2 diabetes and diabetes occurring secondary to other conditions, such as steroid use, Down's syndrome, and congenital malformations of pancreas.

FINDINGS

10,737 children-5816 boys and 4921 girls-were diagnosed with type 1 diabetes before 15 years of age during 1980-2005. The average age-standardised incidence was 42.9 per 100,000 per year (95% CI 42.6-44.3) during this period, increasing from 31.4 per 100,000 per year in 1980 to 64.2 per 100,000 per year in 2005. The age-specific rates per 100,000 per year were 31.0, 50.5, and 50.6 at ages 0-4 years, 5-9 years, and 10-14-years, respectively. We noted a significant non-linear component to the time trend (p<0.0003). In children aged 0-4 years, the increase was largest, at 4.7% more affected every year. The overall boy-to-girl ratio of incidence was 1.1; at the age of 13 years, it was 1.7 (1.4-2.0). The predicted cumulative number of new cases with type 1 diabetes before 15 years of age between 2006 and 2020 was about 10 800.

INTERPRETATION

The incidence of type 1 diabetes in Finnish children is increasing even faster than before. The number of new cases diagnosed at or before 14 years of age will double in the next 15 years and the age of onset will be younger (0-4 years).

Extreme genetic risk for type 1A diabetes in the post-genome era

A series of genes and loci influencing the genetic risk of type 1A (immune-mediated) diabetes are now well characterized. These include genes of the major histocompatibility complex (MHC), polymorphisms 5' of the insulin gene, and PTPN22, as well as more recently defined loci from genome-wide association studies. By far the major determinants of risk for type 1A diabetes are genes within or linked to the MHC and in particular alleles of class II genes (HLA-DR, DQ, and DP). There is evidence that MHC class I alleles contribute and there are additional MHC-linked influences such that for a major subset of relatives of patients there is a risk as high as 80% for siblings, and for the general population a risk as high as 20% can be defined at birth just by analyzing the MHC. We believe the search for additional MHC loci will require analysis of the remarkable long-range identity (up to 9 million base pairs) of extended MHC haplotypes. Current prediction algorithms will likely be greatly improved for the general population when the additional contributing loci of the MHC are defined.

[Insulin therapy for type 1 diabetes mellitus: past and present]

The discovery of insulin can be considered the milestone of diabetes mellitus history and a great achievement for its treatment. The first insulin available was the regular. Afterwards, Hagedorn added the protamine to the insulin, thus, creating the NPH insulin. In the 1950s an insulin free of protamine was synthesized: the lente insulin. With the advent of molecular biology, synthetic human insulin was synthesized using recombinant DNA technology. Most recently several types of insulin analogues were available, providing the patients with better metabolic control. Type 1 diabetes mellitus treatment includes plain substitution and individualization for short-acting plus long-acting insulin according to the physician's assistance, besides regular practice of physical activities and diet orientations. In type 1 diabetes mellitus the insulin of low variability is the best choice since basal/bolus insulin therapy or continuous subcutaneous insulin infusion pump can mimetize the physiological release of insulin by beta cells.