Trends in the incidence of childhood diabetes in south Asians and other children in Bradford, UK

A systematic framework for understanding the microbiome in human health and disease: from basic principles to clinical translation

The human microbiome is a complex and dynamic system that plays important roles in human health and disease. However, there remain limitations and theoretical gaps in our current understanding of the intricate relationship between microbes and humans. In this narrative review, we integrate the knowledge and insights from various fields, including anatomy, physiology, immunology, histology, genetics, and evolution, to propose a systematic framework. It introduces key concepts such as the 'innate and adaptive genomes', which enhance genetic and evolutionary comprehension of the human genome. The 'germ-free syndrome' challenges the traditional 'microbes as pathogens' view, advocating for the necessity of microbes for health. The 'slave tissue' concept underscores the symbiotic intricacies between human tissues and their microbial counterparts, highlighting the dynamic health implications of microbial interactions. 'Acquired microbial immunity' positions the microbiome as an adjunct to human immune systems, providing a rationale for probiotic therapies and prudent antibiotic use. The 'homeostatic reprogramming hypothesis' integrates the microbiome into the internal environment theory, potentially explaining the change in homeostatic indicators post-industrialization. The 'cell-microbe co-ecology model' elucidates the symbiotic regulation affecting cellular balance, while the 'meta-host model' broadens the host definition to include symbiotic microbes. The 'health-illness conversion model' encapsulates the innate and adaptive genomes' interplay and dysbiosis patterns. The aim here is to provide a more focused and coherent understanding of microbiome and highlight future research avenues that could lead to a more effective and efficient healthcare system.

Cracking the type 1 diabetes code: Genes, microbes, immunity, and the early life environment

Type 1 diabetes (T1D) results from a complex interplay of genetic predisposition, immunological dysregulation, and environmental triggers, that culminate in the destruction of insulin-secreting pancreatic β cells. This review provides a comprehensive examination of the multiple factors underpinning T1D pathogenesis, to elucidate key mechanisms and potential therapeutic targets. Beginning with an exploration of genetic risk factors, we dissect the roles of human leukocyte antigen (HLA) haplotypes and non-HLA gene variants associated with T1D susceptibility. Mechanistic insights gleaned from the NOD mouse model provide valuable parallels to the human disease, particularly immunological intricacies underlying β cell-directed autoimmunity. Immunological drivers of T1D pathogenesis are examined, highlighting the pivotal contributions of both effector and regulatory T cells and the multiple functions of B cells and autoantibodies in β-cell destruction. Furthermore, the impact of environmental risk factors, notably modulation of host immune development by the intestinal microbiome, is examined. Lastly, the review probes human longitudinal studies, unveiling the dynamic interplay between mucosal immunity, systemic antimicrobial antibody responses, and the trajectories of T1D development. Insights garnered from these interconnected factors pave the way for targeted interventions and the identification of biomarkers to enhance T1D management and prevention strategies.

Prediction of diabetes prescription volumes of various geographies using regression techniques

Background: Increasing diabetes prevalence is a major public health concern. In this study we ask whether linked open data can be used to predict prescription volumes of drugs used in the treatment of diabetes across small geographies of England. Methods: We propose and demonstrate a methodology of utilising publicly available open data to infer the geo-spatial distribution of prescribed drugs for diabetes, at the lower layer super output area level. Multiple datasets are acquired, processed, and linked together, enabling a more in-depth analysis. Combining these linked datasets with published deprivation factors of geographies across England, we build highly predictive regression models. Results: Regression models were trained and are capable of accurately predicting diabetes prescribing volumes based on deprivation indicators of various geographies across England. Models built with data covering the city of Bradford, England, produced a predicted against actual correlation value of R2 = 0.672 using multiple linear regression and 0.775 using Least Absolute Shrinkage and Selection Operator (LASSO). Median age and air quality factors proved to be significant markers for diabetes prescribing. Conclusions: The results of this study suggest our methodology is robust and accurate. Such predictive models are useful to health authorities in light of increasing costs and increasing prevalence of diabetes. While using publicly available open data negates any issues of data privacy.

Hygiene hypothesis and autoimmune diseases: A narrative review of clinical evidences and mechanisms

Since the start of the "modern era", characterized by the increase in urbanization, a progressive attention to hygiene and autoimmune conditions has considerably grown. Although these diseases are often multifactorial, it was demonstrated that environment factors such as pollution, diet and lifestyles may play a crucial role together with genetic signature. Our research, based on the newest and most significant literature of this topic, highlights that the progressive depletion of microbes and parasites due to increased socioeconomic improvement, may lead to a derangement of immunoregulatory mechanisms. Moreover, special attention was given to the complex interplay between microbial agents, as gut microbiome, diet and vitamin D supplementation with the aim of identifying promising future therapeutic options. In conclusion, autoimmunity cannot be limited to hygiene-hypothesis, but from the point of view of precision medicine, this theory represents a fundamental element together with the study of genomics, the microbiome and proteomics, in order to understand the complex functioning of the immune system.

Revisiting the Hygiene Hypothesis in the Context of Autoimmunity

Initially described for allergic diseases, the hygiene hypothesis was extended to autoimmune diseases in the early 2000s. A historical overview allows appreciation of the development of this concept over the last two decades and its discussion in the context of evolution. While the epidemiological data are convergent, with a few exceptions, the underlying mechanisms are multiple and complex. A major question is to determine what is the respective role of pathogens, bacteria, viruses, and parasites, versus commensals. The role of the intestinal microbiota has elicited much interest, but is it a cause or a consequence of autoimmune-mediated inflammation? Our hypothesis is that both pathogens and commensals intervene. Another question is to dissect what are the underlying cellular and molecular mechanisms. The role of immunoregulatory cytokines, in particular interleukin-10 and TGF beta is probably essential. An important place should also be given to ligands of innate immunity receptors present in bacteria, viruses or parasites acting independently of their immunogenicity. The role of Toll-Like Receptor (TLR) ligands is well documented including via TLR ligand desensitization.

Antipyretics might occupy a narrow temporal position in aetiology of type 1 diabetes: Immunological and intestinal studies required

Geographical variance in the incidence of type 1 diabetes mellitus (T1DM) and its etiological link to viruses and gut microbiome imply causative environmental agents. Antipyretics and especially acetaminophen received some attention recently due to the associations with some autoimmune conditions and lack of studies on the mechanisms influencing the immune system. A couple of recent studies involving large cohorts have found no association between the use of acetaminophen in early childhood and seroconversion leading to T1DM (TEDDY, involving international cohort) or diagnosis of overt T1DM (Norwegian MoBa) in the follow up years. The paper gives the supplemental argumentation for the antipyretic hypothesis presented in Medical Hypotheses in 2016 that is still valid in face of the mentioned conclusions. The hypothesis assumes that critical effect of acetaminophen and possibly other antipyretics expresses itself as the immediate influence on the immune system in the unfortunate coincidence with the other environmental factors, supposedly involving feverish, new to immunity, viral infection, all creating triggering circumstances regardless of age. Young age, in this respect should be regarded as a risk factor due to immatureness of immunity. The paper discusses that antipyretics and particularly acetaminophen need more attention evaluating their possible immunity modulations during infection or through negative effects on intestinal microbiota or both.

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

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

Global and regional estimates of the morbidity due to type I diabetes among children aged 0-4 years: a systematic review and analysis

Background

Epidemiology of type 1 diabetes mellitus (T1DM) among children aged 0-4 years globally is not well understood. We aim to assess the incidence of T1DM in low- and middle-income countries (LMIC) by conducting a systematic review of previous reports. We also aim to address possible contribution to child mortality and to identify any temporal trends.

Methods

A systematic review was performed using a carefully designed search strategy to explore MEDLINE, EMBASE and Global Health databases. Data was extracted from all studies that satisfied the inclusion criteria –a total of 83 records extracted from 26 830 sources that were analysed. We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) process to assess quality of evidence and applied meta-analysis approaches to assess global and regional incidence and time trends.

Results

The overall pooled incidence of T1DM in children aged 0-4 years globally is 11.2 (95% CI = 10.0-12.3) per 100 000 child years. The regional incidence were the highest for European Region A (EUR A) at 15.5 (95% CI = 13.5-17.5) per 100 000 child years. EUR C had the incidence of 10.0 (95% CI = 6.5-13.6) and EUR B 5.8 (95% CI = 4.7-7.0), Region of the Americas A (AMR A) 11.4 (95% CI = 7.8-14.9), AMR B of 2.5 (95% CI = 0.2-4.8), Eastern Mediterranean Region (EMR B) 7.1 (95% CI = 4.2-10.0) and Western Pacific Region (WPR A) 7.0 (95% CI = 2.9-11.0) per 100 000 child years, while other regions had very low rates or no data. When data points were categorised in the study periods and re-analysed, an increasing trend of the T1DM incidence was observed, with the incidence of 20.9 (95% CI = 7.8-34.1) per 100 000 child years in the years 2010-2015, preceded by 13.2 (95% CI = 11.0-15.5) in 2000-2009 study period, 10.0 (95% CI = 8.4-11.7) in 1990-1999 and 8.3 (95% CI = 5.1-11.6) in 1980-1989, respectively. Although the data are scarce, and variation and uncertainty are large, we estimated that the number of new cases of T1DM among children aged 0-4 years in the world each year is between 100 000 and 150 000.

Conclusions

The identified large variation in incidence estimates for different parts of the world, along with scarcity of information and the identified strong temporal increase in T1DM incidence suggest a clear need for further research into this subject.

A stochastic epigenetic Mendelian oligogenic disease model for type 1 diabetes

The incidence of type 1 diabetes (T1D) and some other complex diseases is increasing. The cause has been attributed to an undefined changing environment. We examine the role of the environment (or any changing non-genetic mechanism) in causing the rising incidence, and find much evidence against it: 1) Dizygotic twin T1D concordance is the same as siblings of patients in general; 2) If the environment is responsible for both the discordance among identical twins of patients with T1D and its rising incidence, the twin concordance rate should be rising, but it is not; 3) Migrants from high-to low-incidence countries continue to have high-incidence children; 4) TID incidence among the offspring of two T1D parents is identical to the monozygotic twin rate. On the other hand, genetic association studies of T1D have revealed strong susceptibility in the major histocompatibility complex and many optional additive genes of small effect throughout the human genome increasing T1D risk. We have, from an analysis of previously published family studies, developed a stochastic epigenetic Mendelian oligogenic (SEMO) model consistent with published observations. The model posits a few required recessive causal genes with incomplete penetrance explaining virtually all of the puzzling features of T1D, including its rising incidence and the specific low T1D incidence rates among first-degree relatives of patients. Since historic selection against any causal gene could prevent T1D, we postulate that the rising incidence is because of increasing population mixing of parents from some previously isolated populations that had selected against different causal genes.

Lifestyle Factors Affecting the Gut Microbiota's Relationship with Type 1 Diabetes

PURPOSE OF REVIEW

The incidence of type 1 diabetes (T1D) is rising drastically for the past decades at a rate that cannot be explained by genetic changes alone. Environmental changes are considered to be the main drivers of this change. Recently, the gut microbiota has been suggested as a missing link between known environmental disease modulators and T1D promotion. Lifestyle factors have changed over time and have altered the gut microbiota-host interaction affecting T1D development. The purpose of this review is to discuss recent data emphasizing the modulatory potential of early lifestyle factors on gut microbiota and to elucidate their implication for T1D.

RECENT FINDINGS

Recent findings show that lifestyle factors, especially those that affect the early establishment of gut homeostasis and the education of the immune system, are crucial disease modulators. Changing lifestyle factors affecting the early establishment of gut homeostasis are suggested to be key drivers of the rising T1D incidence.

The hygiene hypothesis in autoimmunity: the role of pathogens and commensals

The incidence of autoimmune diseases has been steadily rising. Concomitantly, the incidence of most infectious diseases has declined. This observation gave rise to the hygiene hypothesis, which postulates that a reduction in the frequency of infections contributes directly to the increase in the frequency of autoimmune and allergic diseases. This hypothesis is supported by robust epidemiological data, but the underlying mechanisms are unclear. Pathogens are known to be important, as autoimmune disease is prevented in various experimental models by infection with different bacteria, viruses and parasites. Gut commensal bacteria also play an important role: dysbiosis of the gut flora is observed in patients with autoimmune diseases, although the causal relationship with the occurrence of autoimmune diseases has not been established. Both pathogens and commensals act by stimulating immunoregulatory pathways. Here, I discuss the importance of innate immune receptors, in particular Toll-like receptors, in mediating the protective effect of pathogens and commensals on autoimmunity.

Climates on incidence of childhood type 1 diabetes mellitus in 72 countries

We are aimed to systematically assess the worldwide trend in incidence of childhood type 1 diabetes mellitus (CT1DM) from 1965 to 2012 and to discuss whether climate affect incidence of CT1DM. We searched the relevant literatures in detail to judge the effect of different climates on incidence of CT1DM. The climates included Mediterranean, monsoon, oceanic, continental, savanna, and rainforest. According to different climates, we further researched relevant factor such as sunshine durations and latitudes. The overall incidence of CT1DM in 72 countries was 11.43 (95% CI 10.31–12.55) per 100,000 children/yr. The incidence of CT1DM in Oceanic climate [10.56 (8.69–12.42)] is highest compared with other climates; the incidence in 40°–66°34′N/S [14.71 (12.30–17.29)] is higher than other latitude groups; the incidence in sunshine durations with 3–4 hours per day [15.17 (11.14–19.20)] is highest compared with other two groups; the incidence of CT1DM from 2000 to 2012 [19.58 (14.55–24.60)] is higher than other periods; all p < 0.01. Incidence of CT1DM was increasing from 1965 to 2012, but incidence in Oceanic climate is higher than other climates. Furthermore, it is higher in centers with higher latitude and lower sunshine durations. The climates might play a key role in inducing CT1DM.

Ethnic differences in the incidence of type 1 diabetes in Norway: a register-based study using data from the period 2002-2009

BACKGROUND

Few studies have looked at variation in type 1 diabetes incidence between immigrant groups within a country.

OBJECTIVE

To investigate differences in incidence rates of childhood-onset type 1 diabetes between immigrant groups and ethnic Norwegians, and their contribution to the number of incident cases of type 1 diabetes in Norway.

SUBJECTS

The study includes 2221 individuals with newly onset type 1 diabetes diagnosed during 2002-2009 in children of 0-14 yr in Norway registered in the nationwide and population-based Norwegian Childhood Diabetes Registry.

METHODS

Incident cases were classified in seven groups based on country of maternal birth and three age groups. Statistics Norway provided the corresponding population sizes. Incidence rates were compared by Poisson regression.

RESULTS

The overall incidence rate was 34.0 cases per 100,000 person-years (95% CI: 32.6, 35.5). There were large variations in incidence across the immigrant groups (p < 0.001), ranging from 6.8 per 100,000 person-years (95% CI: 1.9-17.5) for South/East Asians to 26.0 cases per 100,000 person-years (95% CI: 11.9-49.3) for sub-Saharan Africans. The differences remained significant after adjusting for age and gender.

CONCLUSIONS

There are large variations in the rate of incidence of type 1 diabetes across the ethnic groups, and several immigrant groups have significantly lower incidence than ethnic Norwegians. Immigrant groups contributed ca. 5% of the total cases of type 1 diabetes and influence the overall incidence in Norway only to a small extent.

HLA associated type 1 diabetes risk in children of Pakistani migrants to Norway

Type 1 diabetes (T1D) results from poorly defined interaction between susceptibility genes and environmental factors. The objective was to investigate Human Leukocyte Antigens (HLA) associated T1D risk among Pakistani newborns in Norway based on what published globally. DNA samples from 189 newborns, whose parents were first generation migrants from Pakistan, were analyzed. The hypothesis was tested using high resolution HLA genotyping for the -DRB1 and -DQB1 loci and high/intermediate for the -DQA1 locus. We identified 28 different DRB1, 13 DQB1 and 9 DQA1 alleles. Of the 39 different haplotypes identified, only five have been reported to confer T1D susceptibility. Among these the DR3-DQ2 (DRB1*03:01:01-DQA1*05-DQB1*02:01:01) haplotype was found in 18.5% (n=70) of the newborns, and 18.6% (n=13) of these were homozygotes. A diverse range of HLA haplotypes were identified amongst an ethnically homogenous group of newborns, with only a small proportion associated with T1D risk. The incidence of T1D among immigrants form South/East Asia is the lowest in the Norwegian Type 1 Diabetes Registry. The few included so far, are children of first generation immigrants. If incidence of T1D rises in the Norwegian Pakistani childhood population, as observed in the UK, then environmental triggers rather than genetic susceptibility will be the explanation.

Long-term survival with revascularization in South Asians admitted with an acute coronary syndrome (from the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease Registry)

People of South Asian (SA) descent are particularly susceptible to acute coronary syndromes (ACS). Yet, little information exists regarding their overall prognosis. The purpose of this study was to compare short- and long-term clinical outcomes of SA and European Canadians admitted with an ACS. Using the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease registry, 63,393 patients with ACS were reviewed (January 1999 to March 2012). After excluding Chinese patients, 1,825 SAs were compared with 60,791 European Canadians. Both groups were propensity matched, and outcomes were compared. Adjustment was performed using a 3:1 propensity matching technique. Adjusted 30-day and 1-year mortality rates were similar between SA and European patients with ACS (2.6% vs 2.7%, p = 0.93; 5.0% vs 4.8%, respectively, p = 0.75). Repeat angiography did not differ (9.9% vs 9.2%, p = 0.35), yet repeat revascularization within 1 year was greater in SA patients (9.8% vs 7.6%, p <0.01). Improved long-term survival (median 64 months, interquartile range 66 months) was noted with SA patients (hazard ratio [HR] 0.82, 95% confidence interval [CI] 0.71 to 0.95). In particular, long-term survival was observed in SA patients receiving coronary artery bypass grafting (HR 0.75, 95% CI 0.52 to 1.08) and percutaneous coronary intervention (HR 0.75, 95% CI 0.59 to 0.96). In conclusion, SA patients treated with revascularization appear to have improved long-term survival after ACS, compared with European Canadians. As such, clinicians should be cognitive of ethnic-based outcomes when determining therapeutic strategies in patient management.

Epidemiological issues in diabetic retinopathy

There is currently an epidemic of diabetes in the world, principally type 2 diabetes that is linked to changing lifestyle, obesity, and increasing age of the population. Latest estimates from the International Diabetes Federation (IDF) forecasts a rise from 366 million people worldwide to 552 million by 2030. Type 1 diabetes is more common in the Northern hemisphere with the highest rates in Finland and there is evidence of a rise in some central European countries, particularly in the younger children under 5 years of age. Modifiable risk factors for progression of diabetic retinopathy (DR) are blood glucose, blood pressure, serum lipids, and smoking. Nonmodifiable risk factors are duration, age, genetic predisposition, and ethnicity. Other risk factors are pregnancy, microaneurysm count in an eye, microaneurysm formation rate, and the presence of any DR in the second eye. DR, macular edema (ME), and proliferative DR (PDR) develop with increased duration of diabetes and the rates are dependent on the above risk factors. In one study of type 1 diabetes, the median individual risk for the development of early retinal changes was 9.1 years of diabetes duration. Another study reported the 25 year incidence of proliferative retinopathy among population-based cohort of type 1 patients with diabetes was 42.9%. In recent years, people with diabetes have lower rates of progression than historically to PDR and severe visual loss, which may reflect better control of glucose, blood pressure, and serum lipids, and earlier diagnosis.

DNA methylation impairs TLR9 induced Foxp3 expression by attenuating IRF-7 binding activity in fulminant type 1 diabetes

Fulminant type 1 diabetes (FT1D) is an extremely aggressive disease characterized by the abrupt onset of insulin-deficient hyperglycemia. However, the precise mechanisms underlying disease etiology almost remain unclear. As mice deficient in regulatory T cells (Tregs) are prone to the development of an FT1D-like phenotype, we thus investigated whether FT1D patients manifest Treg deficiency and explored the related mechanisms. We first noted a significant reduction for Foxp3 and CTLA4 expression levels in PBMCs of FT1D patients. IRF-7 was found to selectively bind to the Foxp3 promoter, and by which it promotes Foxp3 transcription. Therefore, ectopic IRF-7 expression significantly promoted Foxp3 and CTLA4 expression in PBMCs, while knockdown of IRF-7 manifested opposite effect. Importantly, stimulation of PBMCs with CpG ODN, a ligand for TLR9, significantly induced Foxp3 expression, demonstrating that TLR9 signaling positively regulates Treg development. However, knockdown of IRF-7 expression almost completely diminished the enhancing effect of TLR9 signaling on Foxp3 expression, suggesting that IRF-7 is a downstream molecule of TLR9 signaling and is essential for TLR9 induced Treg generation. Of interestingly note, the Foxp3 promoter in FT1D patients was hypermethylated, indicating that DNA methylation could be a causative factor responsible for the reduced Foxp3 expression in FT1D patients. Indeed, our mechanistic studies revealed that DNA methylation blocked IRF-7 binding to the Foxp3 promoter. Together, our data support the notion that environmental insults in genetic predisposed subjects trigger Foxp3 promoter hypermethylation, which then prevents IRF-7 binding to the Foxp3 promoter and impairs Treg development/functionality contributing to the pathogenesis of FT1D.

Incidence rate trends in childhood type 1 diabetes in Yorkshire, UK 1978-2007: effects of deprivation and age at diagnosis in the South Asian and non-South Asian populations

AIMS

Incidence of Type 1 diabetes in children is increasing worldwide. Earlier studies suggest that UK south Asian immigrants develop similar rates to the overall UK population, although incidence is lower in their country of origin. This study examines incidence rate trends of childhood Type 1 diabetes in Yorkshire 1978-2007, focusing on differences between south Asians and non-south Asians.

METHODS

Data from the population-based Yorkshire Register of Diabetes in Children and Young People were used to estimate incidence (per 100,000 childhood population < 15 years per year) of Type 1 diabetes, stratified by sex, age and ethnicity validated using two name-recognition programs. Age-sex standardized rates were calculated for 1978-2007 and assessed by ethnic-group and deprivation for 1990-2007. We used Poisson regression to assess incidence trends and predict rates until 2020.

RESULTS

From 1978-2007, 3912 children were diagnosed. Overall incidence was 18.1 per 100,000 childhood population (< 15 years) per year (95% CI17.6-18.7) and increased significantly over time: 13.2 (1978-1987) to 17.3 (1988-1997) to 24.2 (1998-2007). Average annual percentage change was 2.8% (2.5-3.2). Incidence for non-south Asians (21.5; 20.7-22.4) was significantly higher than for south Asians (14.7; 12.4-17.1). Average annual percentage change increased significantly over 18 years (1990-2007) in non-south Asians (3.4%; 2.7-4.2) compared with a non-significant rise of 1.5% (-1.5 to 4.6) in south Asians. Deprivation score did not affect overall incidence.

CONCLUSIONS

Type 1 diabetes incidence rose almost uniformly for non-south Asians, but not for south Asians, contrary to previous studies. Overall rates are predicted to rise by 52% from 2007 to 2020 to 39.0 per 100,000 per year.

Rising rates of all types of diabetes in south Asian and non-south Asian children and young people aged 0-29 years in West Yorkshire, U.K., 1991-2006

OBJECTIVE

To investigate incidence trends of all diabetes types in all children and young people and in the south Asian subpopulation.

RESEARCH DESIGN AND METHODS

Annual incidence per 100,000 and time trends (1991-2006) were analyzed for 2,889 individuals aged 0-29 years diagnosed with diabetes while resident in West Yorkshire, U.K.

RESULTS

Diagnoses comprised type 1 (83%), type 2 (12%), maturity-onset diabetes of the young (0.7%), "J"-type/other (0.1%), and uncertain/unclassified (4%). There was a lower incidence of type 1 and a threefold excess of type 2 in south Asians compared with non-south Asians. Type 1 incidence leveled out and type 2 increased after the first south Asian case of type 2 was diagnosed in 1999. Type 2 and unclassified diabetes incidence rose in all population subgroups.

CONCLUSIONS

The burden of diabetes increased over time for both ethnic groups, with a significant excess of type 2 diabetes in south Asians. The rising incidence of type 1 diabetes in south Asians attenuated as type 2 diabetes increased after 1999.

Type 1 diabetes patients born to immigrants to Sweden increase their native diabetes risk and differ from Swedish patients in HLA types and islet autoantibodies

AIM

To determine whether type 1 diabetes mellitus (T1DM) patients, having parents who immigrated to Sweden, have increased T1DM risk before 18 yr compared with countries of origin. We also determined whether they have different human leukocyte antigen (HLA) genetic markers and islet autoantibodies at diagnosis compared with Swedish patients.

METHODS

A total of 1988 (53% males) newly diagnosed and confirmed T1DM patients <18 yr registered within the Better Diabetes Diagnosis (BDD) study (May 2005 to September 2008) were included. Participants were classified into three groups: Swedish, non-Swedish, and Mixed-origin patients according to country of origin of two generations (parents and grandparents). These groups were compared with respect to T1DM HLA markers and islet autoantibodies [glutamic acid decarboxylase autoantibodies (GAD65Ab), insulin autoantibodies (IAA), and islet antigen-2 autoantibodies (IA-2Ab)].

RESULTS

Only 30 (1.5%) patients were born outside Sweden. Swedish patients constituted 66%, non-Swedish patients 8%, Mixed origins 17%, and 9% were of uncertain origin. Confirmed T1DM in patients within the study was 22 (95% CI: 21-23) patients/10(5)/yr rate for Swedish patients compared with 14 (95% CI: 13-15) among non-Swedish patients. The HLA-DQ8 haplotype (p < 0.0001) and DQ2/8 genotype (p < 0.02) predominated among Swedish compared with non-Swedish patients. In contrast, DQ2 was the most frequent haplotype among non-Swedish patients [OR = 1.5 (95% CI: 1.0-2.0), p < 0.04]. Multiple (≥2) autoantibodies (p < 0.04) and specifically IA-2Ab (p < 0.001) were most prevalent among the Swedish patients. Multiple autoantibodies were associated with DQ8 among the Swedish patients only (p < 0.001).

CONCLUSION

Patients born to parents who had immigrated to the high T1DM incidence environment of Sweden have, compared with Swedish patients, more frequent HLA-DQ2 genetic markers and are diagnosed more often with GAD65Ab.

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.

Statin therapy in South Asians-facts and future

South Asians have higher overall burden of coronary heart disease. South Asian migrants suffer from more severe and fatal coronary heart disease at younger age despite similar risk factors compared with local population. Elevated blood cholesterol contributes to atherosclerosis and heart disease and is one of the primary modifiable risk factor for these conditions. Since the discovery of a fungal metabolite that inhibits 3-hydroxy-3methyl-glutaryl-coenzyme A reductase, statins have emerged rapidly as the global leader in medical therapeutics designed to lower low-density lipoprotein cholesterol and had reduced mortality and morbidity from coronary heart disease when used for primary or secondary prevention. Despite the considerable burden imposed by cardiovascular disease, South Asians remain inadequately targeted for risk-reduction strategies, including screening and treatment for dyslipidemia.

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.

Suicide rates in people of South Asian origin in England and Wales: 1993-2003

BACKGROUND

Low rates of suicide in older men and high rates in young women have been reported in the South Asian diaspora worldwide. Calculating such suicide rates in the UK is difficult because ethnicity is not recorded on death certificates.

AIMS

To calculate the South Asian origin population suicide rates and to assess changes over time using new technology.

METHOD

Suicide rates in England and Wales were calculated using the South Asian Name and Group Recognition Algorithm (SANGRA) computer software.

RESULTS

The age-standardised suicide rate for men of South Asian origin was lower than other men in England and Wales, and the rate for women of South Asian origin was marginally raised. In aggregated data for 1999-2003 the age-specific suicide rate in young women of South Asian origin was lower than that for women in England and Wales. The suicide rate in those over 65 years was double that of England and Wales.

CONCLUSIONS

Older, rather than younger, women of South Asian origin seem to be an at-risk group. Further research should investigate the reasons for these changes and whether these patterns are true for all South Asian origin groups.

Parental country of birth is a major determinant of childhood type 1 diabetes in Sweden

OBJECTIVE

To test the hypothesis that the risk of childhood diabetes type 1 increases with migration from a low to a high incidence region.

METHODS

Register study of a national cohort of 783 547 children born between 1987 and 1993 who remained in Sweden in 2002, including 3225 children with childhood type 1 diabetes identified in hospital discharge data. Logistic regression analysis was used to test the hypotheses.

RESULTS

Offspring of two parents born in very low (Asia excluding Middle East and Latin America) and low (southern and eastern Europe and the Middle East) incidence regions had the lowest adjusted odds ratios (ORs) of childhood type 1 diabetes; 0.21 (0.11-0.41) and 0.37 (0.29-0.48), respectively, compared with the Swedish majority population. When one parent was born in a low incidence country and one parent was Swedish born, the adjusted ORs increased but remained lower than the Swedish majority population.

CONCLUSIONS

Parental country of birth is an important determinant of childhood type 1 in Sweden. Heritable factors seem most likely to explain this pattern.

Medicinal perceptions of vegetables traditionally consumed by South-Asian migrants living in Bradford, Northern England

Dietary habits change rapidly amongst migrant communities in Western countries, and these changes can cause major concerns for public-health policymakers because they frequently lead to increases in diet-related diseases like diabetes. Such is the case in most South-Asian communities in the UK. In this study, we carried out an ethnobiological survey of the vegetables traditionally consumed among the Indian and Pakistani communities of Bradford, in Western Yorkshire, UK. Our purpose was to analyse in depth details of the traditional culinary use of vegetables within these households, and to assess the health perceptions of them. Semi-structured interviews with a total of 150 South-Asian women were carried out. Twenty-five vegetables were recorded, as well as their traditional culinary use and their frequency of use. We found that a few of these vegetables, particularly those presenting bitter or aromatic tastes, were perceived to have remarkable medicinal value particularly against diabetes. Our study also found important generational differences in the women's knowledge of the culinary processes related to these foods, confirming that the consumption of traditional vegetables is inextricably embedded in cultural heritage and the representation of identity among migrants. Our findings may offer evidence of a link between the choice of food and the foods' perceived medicinal value among South-Asian migrants. It may also provide important information for health care professionals when designing strategies for improving health care counteracting type 2 diabetes. We strongly believe such strategies should take into account socio-cultural components and emic health beliefs, as well as patients' views of traditional dietary ingredients.

Asian MODY: are we missing an important diagnosis?

AIMS

Maturity onset diabetes of the young (MODY) is a monogenic form of diabetes where correct diagnosis alters treatment, prognosis and genetic counselling. The first UK survey of childhood MODY identified 20 White, but no Asian children with MODY. We hypothesized that MODY causes diabetes in UK Asians, but is underdiagnosed.

METHODS

Children with dominant family histories of diabetes were recruited. Direct sequencing for mutations in the two most common MODY genes; HNF1A (TCF1) and GCK was performed in autoantibody-negative probands. We also compared MODY testing data for Asian and White cases from the Exeter MODY database, to 2001 UK census data.

RESULTS

We recruited 30 families and identified three Asian families with MODY gene mutations (two HNF1A, one GCK) and three White UK families (two HNF1A, one GCK). Heterozygous MODY phenotypes were similar in Asians and Whites. Only eight (0.5%) of 1369 UK referrals for MODY testing were known to be Asian, but in 2001 Asians represented 4% of the English/Welsh population and have a higher prevalence of diabetes.

CONCLUSIONS

We identified three cases of childhood MODY in UK Asians and demonstrated reduced rates of MODY testing in Asians, which has negative implications for treatment. It is unclear why this is. MODY should be considered in autoantibody-negative Asian diabetes patients lacking evidence of insulin resistance.

Putting the pieces of the puzzle together - a series of hypotheses on the etiology and pathogenesis of type 1 diabetes

This paper presents a series of 10 hypotheses on the etiology of type 1 diabetes. We begin with the hypothesis that wheat gluten is one of the elusive environmental triggers in type 1 diabetes. Habitual consumption of wheat gluten increases the intestinal synthesis of dipeptidyl peptidase IV. This enzyme helps to shape the repertoire of peptides released into the small intestine following the ingestion of wheat gluten by catalyzing the release of X-Pro dipeptides from the N-terminus of the proline-rich glutenins and gliadins in wheat gluten. The release of gluten-derived peptides causes the tight junctions of the small intestine to open through a zonulin-dependent mechanism, which allows these peptides to enter the lamina propria where they get presented as antigens by HLA-DQ, -DR and CD1d molecules. Binding of one or more gluten peptides by CD1d leads to abrogation of oral tolerance, and a marked increase in peripheral immune responses to wheat proteins. Furthermore, it is our contention, that in response to beta cell apoptosis during normal remodeling of the pancreas and CCL19/CCL21 expression within the pancreatic lymph nodes (PLNs), gluten-loaded dendritic cells migrate from the small intestine to the PLNs. These dendritic cells present gluten-derived antigens on the surface of the PLNs, which leads to migration of CD4(-)CD8(-) gammadelta and CD4(-)CD8(+) alphabeta T cells to the pancreas where they mediate Fas and perforin dependent cytotoxicity. We also hypothesize that at least one of the type 1 diabetes associated HLA-DR molecules that bind and present wheat-derived peptide(s) also bind and present an islet cell antigen(s), activating plasma cell synthesis of islet cell autoantibodies and irrevocable, complement-dependent destruction of islet cells. Our final two hypotheses state that type 1 diabetes morbidity is reduced in those areas of globe where genetically susceptible individuals get adequate amounts of vitamin D, in the diet and/or through exposure to sunlight, and in areas where people are exposed to bacterial, viral, or parasitic infections in early childhood.

The responses of lymphocytes from Asian and Caucasian diabetic patients and non-diabetics to hydrogen peroxide and sodium nitrite in the Comet assay

Numerous factors may influence the incidence of diabetes in the population. The production of reactive oxygen species (ROS) is elevated in diabetes patients. Based on the reported involvement of reactive species and nitrate/nitrite in diabetes, this present study has examined in the alkaline Comet assay, the effect of different levels of NaNO(2) in the presence of the oxygen radical generating agent, hydrogen peroxide (H(2)O(2)). Peripheral lymphocytes from diabetic and non-diabetic Caucasians and Asians of both sexes were studied in vitro. Endogenous factors (e.g., sex, age, body mass index-BMI) and exogenous factors (lifestyle factors e.g., smoking and drinking habits, diet) were taken into account. A preliminary study in two individuals showed that DNA damage remained constant over a wide dose range of NaNO(2) (1-75mM), but when H(2)O(2) was added at a constant concentration of 50microM per dose of NaNO(2), there was an increase in DNA damage corresponding with the varying levels of NaNO(2) investigated. This was also seen with the 44 individuals (non-diabetic, n=24; type 1 diabetic, n=11; type 2 diabetic, n=9) investigated. NaNO(2) was capable of inducing a significant level of DNA damage in lymphocytes (p<0.001), but only with the addition of H(2)O(2). When levels of DNA damage were analysed in terms of the different variables there were few significant differences in damage between diabetic and non-diabetic subjects, or other sub-population groups, and no statistically significant differences in susceptibility were observed between subject covariates using regression techniques.

Type 2 diabetes and cardiovascular risk in the UK south Asian community

A popular hypothesis for the greater prevalence of type 2 diabetes and cardiovascular disease in UK south Asians is that they have an increased susceptibility of developing insulin resistance in response to certain environmental factors, including obesity and adoption of a sedentary lifestyle. Insulin resistance is postulated as a central feature of the metabolic syndrome, culminating in type 2 diabetes, atherosclerotic vascular disease and CHD; a pathway potentially accelerated by migration/urbanisation. We describe and compare the prevalence of type 2 diabetes, cardiovascular disease and their associated risk factors in UK south Asian and white Caucasian populations to determine possible reasons for the increased preponderance of these diseases in south Asians, and highlight key evidence for optimal risk factor management. Finally, we describe a UK community-based programme that attempts to reduce the morbidity and mortality from type 2 diabetes and cardiovascular disease in south Asians through a new approach to management.

Detecting small-area similarities in the epidemiology of childhood acute lymphoblastic leukemia and diabetes mellitus, type 1: a Bayesian approach

Childhood acute lymphoblastic leukemia and diabetes mellitus, type 1, have common epidemiologic and etiologic features, including correlated international incidence and associations with infections. The authors examined whether the diseases' similar large-scale distributions are reflected in small geographic areas while also examining the influence of sociodemographic characteristics. Details of 299 children (0-14 years) with acute lymphoblastic leukemia and 1,551 children with diabetes diagnosed between 1986 and 1998 were extracted from two registers in Yorkshire, United Kingdom. Standardized incidence ratios across 532 electoral wards were compared using Poisson regression, confirming significant associations between population mixing and the geographic heterogeneity of both conditions. Bayesian methods analysis of spatial correlation between diseases by modeling a bivariate outcome based on their standardized incidence ratios was applied; spatial and heterogeneity components were included within a hierarchical random effects model. A positive correlation between diseases of 0.33 (95% credible interval: -0.20, 0.74) was observed, and this was reduced after control for population mixing (r = 0.18), population density (r = 0.14), and deprivation (r = 0.06). The Bayesian approach showed a modest but nonsignificant joint spatial correlation between diseases, only partially suggesting that the risk of both was associated within some electoral wards. With Bayesian methodology, population mixing remained significantly associated with both diseases. The links between diabetes and acute lymphoblastic leukemia observed for large regions are weaker for small areas. More powerful replications are needed for confirmation of these findings.

Diabetes in children and adolescents from ethnic minorities: barriers to education, treatment and good metabolic control

AIM

This paper reports an investigation to establish whether metabolic control is different in children and adolescents from ethnic minorities with type 1 diabetes compared with young Danish patients, and to learn about factors affecting their opportunities to achieve good metabolic control.

BACKGROUND

The prevalence of diabetes in children and adolescents from ethnic minorities in Denmark is increasing. Having a different ethnic background has frequently been described as a risk factor for poor metabolic control, but whether the risk is represented by the ethnicity and immigration itself or in combination with other factors is unclear.

METHODS

The study included data (gender, age, diabetes duration HbA(1c), number of incidents of severe hypoglycaemia and ketoacidosis) from a national register including 919 Danish and 58 children and adolescents from ethnic minorities, questionnaires to all 20 Danish paediatric diabetes centres and questionnaires to 38 families of other ethnic backgrounds completed by professional interpreters. The study was conducted in 2001-2002.

RESULTS

HbA(1c) was significantly higher in children and adolescents from ethnic minorities (mean 9.05 +/- 1.4%) compared with Danish patients (mean 8.62 +/- 1.3%; P = 0.018). There was no significant difference in HbA(1c) among the different ethnic groups, nor in the prevalence of severe hypoglycaemia or ketoacidosis. Patients from different ethnic minorities were unevenly distributed throughout the country, and generally the centres provided limited specialized knowledge and support. The questionnaires completed by the parents revealed limited schooling, lack of professional education and a major need for interpreters; these characteristics were especially prevalent among the mothers.

CONCLUSIONS

Young patients from ethnic minorities have significantly poorer metabolic control compared with Danish patients, and patients with an immigrant background are seen as a vulnerable group with different needs and probably fewer chances of achieving good control. Special education for health care professionals as well as projects to improve methods, quality and knowledge should be encouraged in order to provide tailored support to members of individual ethnic groups. We recommend that the use of professional interpreters should become the gold standard in health care provision to all immigrant families.

Increasing body weight predicts the earlier onset of insulin-dependant diabetes in childhood: testing the 'accelerator hypothesis' (2)

AIMS AND METHODS

It has recently been hypothesized that weight gain in childhood accelerates the onset of Type 1 diabetes, as well as increasing its risk, and that Type 1 diabetes and Type 2 diabetes may be one and the same disorder of insulin resistance. An explanation is needed for the rising incidence of childhood diabetes and, to test the Accelerator Hypothesis, we examined the anthropometric measurements recorded from birth in 168 young people presenting with Type 1 diabetes between 1980 and 2002. Pre-onset as well as peri- and post-onset measurements of height and weight were available, and waist circumference was recorded at various intervals after onset.

RESULTS

The mean birth weight of the children and their height, weight and body mass index (BMI) at diagnosis lay close to the population mean. However, pre-onset and post-onset BMI were both well above the population mean, were closely correlated with each other (r = 0.79, P < 0.001) and (inversely) with age at onset (r = -0.30, P < 0.001). A significant correlation was also found between BMI standard deviation scores (sds) and year of diagnosis (r = 0.27, P < 0.001) and, importantly, waist circumference sds in the children with Type 1 diabetes was found to be substantially greater than average for the population [boys: +0.96 (sd 1.04), girls: +1.30 (sd 0.89)].

CONCLUSIONS

The data suggest that children with Type 1 diabetes have become progressively heavier at diagnosis over the past 20 years, and that the heavier child develops it earlier. Waist circumference, a proxy for visceral fat mass and insulin resistance, is substantially greater in children with Type 1 diabetes. Weight centile crossing appears to be an important environmental accelerator which may contribute to or account for the striking increase in both Type 1 diabetes and Type 2 diabetes in childhood. A reduction of body weight and improved lifestyle might reverse this trend in both types of diabetes.

Antioxidant activity of five vegetables traditionally consumed by south-Asian migrants in Bradford, Yorkshire, UK

Five vegetables traditionally consumed among South-Asian migrants in Bradford (Yorkshire, UK) were tested for their free radical scavenging activity (FRSA) in the DPPH (1,1-diphenyl-2-picrylhydrazil radical) screening assay (using extracts prepared both by cold maceration and also by boiling the plant in the solvent under reflux) and for their in vitro non-enzymatic inhibition of bovine brain lipid peroxidation. In both antioxidant assays a strong activity was shown by extracts derived from okra (Abelmoschus esculentus, Malvaceae) fruits and charungli (Caralluma edulis, Asclepiadaceae) aerial parts. Extracts from bitter melon (Momordica charantia, Cucurbitaceae) and angular loofah (Luffa acutangula) showed a significant difference in the FRSA between the extract obtained by using cold maceration and that prepared by boiling the plant in the solvent under reflux, suggesting the chemical composition of the plant changed during the heating process, leading to an increase in the amount of antioxidant components. These findings confirm the great interest of the nutraceutical sciences in extracts of Caralluma edulis, whose phytochemistry and phytopharmacology should be investigated further in order to detect possible phytotherapeutic uses in the prevention of ageing related diseases (ARDs) and Alzheimer disease (AD).

Younger age at diagnosis of type 1 diabetes mellitus in children of immigrated families born in Italy

The aim of this study was to evaluate the age of immigrants' children at diagnosis of Type 1 diabetes (T1DM) according to their country of birth. Immigration from developing countries to a westernised area causes rapid changes in the environmental conditions, and we investigated whether the location of birth, either inside or outside Italy, is associated with age at diagnosis of diabetes. Out of a prevalent hospital-based cohort of 5718 T1DM children cared for in 2002 in 47 Italian Pediatric Diabetes Units, we recruited 195 children (M: 97) of immigrants from developing countries--119 were born in Italy and 76 outside the European Union. Children with only one immigrant parent (no. 42) were also included. Age at diagnosis of T1DM, and other variables were compared with those of Italian children. Children of immigrated families born in Italy developed T1DM at a median age of 4.0 yr (IQR 2.2-6.9), whereas those born in developing countries and that had immigrated to Italy after birth developed T1DM at a median age of 7.9 yr (IQR 5.1-10.7, p < 0.001). Among the children born in Italy, 77 had parents who were both immigrants and the children's median age at diagnosis was 3.8 yr (IQR 2.1-6.3); 42 had only one immigrant parent and, when it was the father (no. = 23), median age was even younger (2.9 yr, IQR 2.0-8.2). Ten children had immigrated in their first yr of life and their median age was 9.1 yr (IQR 5.0-10.6). The median age of the Italian children was 6.6 yr (IQR 3.6-9.5). Results show that the outbreak of T1DM is earlier in immigrants' children born in Italy than in original countries.

Etiology and outcome of childhood and adolescent diabetes mellitus in North India

The etiology of childhood onset diabetes mellitus (DM) varies between regions and races, and its long-term outcome is affected by social and economic factors. There are scant data on the etiology of childhood DM and outcome of multidisciplinary team management from developing countries. We retrospectively analyzed case records of 160 predominantly middle socio-economic group patients with onset of DM < or =18 years of age for etiology and features at presentation. In addition, we prospectively studied acute and chronic complications and metabolic control in a subset of 67 patients. Type 1 DM comprised 81%, type 2 DM 8%, and fibrocalculous pancreatic DM 9% of patients. Mean HbA1c was 8.0+/-1.5%. Retinopathy was present in 22% and nephropathy in 18% of those with DM duration > or =5 years (mean age 21.2+/-6.8 years, mean duration 10.2+/-4.6 years). The frequency of ketoacidosis and severe hypoglycemia was 5.0 and 3.3 episodes per 100 patient years. Mortality was 7% over 823 person years of follow up. We conclude that fairly good metabolic control is achievable in a middle socio-economic population in India, with the assistance of a diabetes education program. The frequency of microvascular complications is comparable to that in the literature. However, mortality remains unacceptably high.

Vitamin D deficiency in early life accelerates Type 1 diabetes in non-obese diabetic mice

AIMS/HYPOTHESIS

1,25-dihydroxyvitamin D(3), the active form of vitamin D, prevents Type 1 diabetes in non-obese diabetic (NOD) mice. Epidemiological data show a threefold increase in human Type 1 diabetes when vitamin D deficiency was present in the first months of life. To evaluate whether a similar dietary deficiency affects diabetes incidence in NOD mice, we generated NOD mice with vitamin D deficiency in early life.

METHODS

Breeding pairs of NOD mice, as well as their offspring (test mice), were kept in surroundings devoid of ultraviolet light and were fed a vitamin D-depleted diet for 100 days. Mice were followed for 250 days.

RESULTS

At 250 days, 35% (12/35) male and 66% (22/33) female vitamin D-deficient mice were diabetic compared to 15% (6/40, p=0.05) and 45% (13/29, p<0.01) of the control mice. At 100 days no difference in insulitis was seen, but more vitamin D-deficient mice were glucose intolerant. Higher IL1 expression was detected in islets of vitamin D-deficient mice and their peritoneal macrophages had an aberrant cytokine profile (low IL1 and IL6, high IL15). Thymus and lymph nodes of vitamin D-deficient mice contained less CD4(+)CD62L(+) cells.

CONCLUSION/INTERPRETATION

Vitamin D status increases the expression of Type 1 diabetes in NOD mice. Our data in NOD mice, as well as human epidemiological data, point to the importance of preventing vitamin D deficiency in early childhood. Controlling this dietary factor could be an easy and safe way to reduce the incidence of Type 1 diabetes in subjects who are genetically at risk.

Enteroviruses and type 1 diabetes

The development of type 1 diabetes mellitus (T1DM) has been linked to exposure to environmental triggers, with Enteroviruses (EV) historically considered the prime suspects. Early serological studies suggested a link between EV infections and the development of T1DM and, though controversial, have been bolstered by more recent studies using more sensitive techniques such as direct detection of the EV genome by RT-PCR in peripheral blood. In this review, we consider the weight of evidence that EV can be considered a candidate trigger of T1DM, using three major criteria: (1) is EV infection associated with clinical T1DM, (2) can EV trigger the development of autoimmunity and (3) what would explain the putative association?

The burden of type 2 diabetes: are we doing enough?

Increasing levels of obesity, arising from energy-rich diets and sedentary lifestyles, are driving a global pandemic of type 2 diabetes. The prevalence of type 2 diabetes worldwide is set to increase from its present level of 150 million, to 225 million by the end of the decade and to as many as 300 million by 2025. Shocking as they are, these figures represent only clinically diagnosed diabetes, and many more cases of diabetes remain undiagnosed and untreated. In addition, up to one-quarter of western populations have impaired glucose tolerance or the dysmetabolic syndrome, which are considered to represent pre-diabetic states. Type 2 diabetes is appearing increasingly in children and adolescents, and the frequency of diagnosis of paediatric type 2 diabetes is outstripping that of type 1 diabetes in some areas. The long-term complications associated with type 2 diabetes carries a crushing burden of morbidity and mortality, and most type 2 diabetic patients die prematurely from a cardiovascular event. Diabetic patients are more than twice as costly to manage as non-diabetic patients, due mainly to the high costs associated with management of diabetic complications. Indeed, diabetes care already accounts for about 2-7% of the total national health care budgets of western European countries. Controlling the type 2 diabetes epidemic will require changes to the structure of healthcare delivery. Well-resourced interventions will be required, with effective co-ordination between all levels of government, health care agencies, multidisciplinary health care teams, professional organisations, and patient advocacy groups. Above all, intervention is needed today.

Type 2 and other forms of diabetes in 0-30 year olds: a hospital based study in Leeds, UK

BACKGROUND AND AIMS

Following recent reports of increased numbers of adolescents being diagnosed with the adult or type 2 form of diabetes we aimed to describe the prevalence of both type 2 and other forms of diabetes in an urban population of children and young people in northern England.

METHODS

A hospital based cross sectional study was performed in patients aged < or =30 years attending diabetic clinics in Leeds during the year 2000.

RESULTS

A total of 677 subjects were identified, of whom 621 (92%) and 37 (5%) had type 1 and type 2 diabetes respectively. Four patients had confirmed maturity onset diabetes of the young, while the cause was uncertain for four. Median age of all patients was 22 years, with 396 (58%) aged 20-30; 32/37 patients with type 2 diabetes were aged 20-30. The prevalence of type 2 diabetes was 0.13 per 1000 overall, compared to 2.2 per 1000 for patients with type 1 diabetes. Of all type 2 diabetes patients, 24% were south Asian compared to 5% of the background population; 87% were categorised into the two least affluent tertiles of the Townsend score. This link with deprivation was not explained by the proportion of Asian patients across tertiles (approximately 25%).

CONCLUSIONS

This study shows extremely low prevalence of type 2 diabetes in 10-19 year olds, but will provide a baseline for future comparisons. Overall, type 2 diabetes is seen more commonly in south Asians, and an association with deprivation is suggested.