The incidence of type 1 diabetes in the age group 0-39 years has not increased in Antwerp (Belgium) between 1989 and 2000: evidence for earlier disease manifestation

Incidence of type 1 diabetes mellitus in Asturias (Spain) between 2011 and 2020

INTRODUCTION

Type 1 diabetes mellitus (DM1) is a chronic disease with important socio-health repercussions that requires epidemiological information for proper health management. The aim of this study was to determine the incidence of DM1 in Asturias between 2011-2020.

METHODS

Descriptive study which included diagnoses of DM1 in Asturias between 2011-2020 captured as a primary source by reviewing the register of pancreatic autoimmunity analysis. Incidence rates were estimated, expressed per 100,000 population-years of risk by age group, sex, and health area.

RESULTS

A total of 815 patients were diagnosed, 53.13% men. The mean age was 34.32±22.07 years; 9.85±4.46 in children under 19 years of age (10.48±4.45 in males and 9.00±4.36 in females). Of the diagnoses, 55.34% occurred at an age over 30 years. The incidence was 7.82 (7.29-8.37); 19.65 (17.17-22.39) in under 15s and 12.84 (11.73-14.03) in under 40s. The maximum incidence peak was between 10-14 years, both in males 31.16 (23.89-39.95) and in females 21.72 (15.59-29.47). There was no significant increase in incidence over the years studied.

CONCLUSIONS

Asturias has a high incidence of DM1. In our study no earlier age at diagnosis was observed or an increase in incidence. Compared to previous studies, the increase in incidence is most likely due to an improvement in data capture, not to a real increase in incidence. A high percentage of diagnoses occur in adulthood.

Prevalence of type 1 and type 2 diabetes in children and adolescents in Germany from 2002 to 2020: A study based on electronic health record data from the DPV registry

BACKGROUND

To provide estimates of the nationwide prevalence of type 1 diabetes (T1D) and type 2 diabetes (T2D) in individuals younger than 20 years of age in Germany from 2002 to 2020 and to identify trends.

METHODS

Data were obtained from the electronic health record "Diabetes Prospective Follow-up Registry (DPV)" specific to diabetes care. Prevalence was estimated based on prevalent cases at the end of each year for the years 2002, 2008, 2014, and 2020 per 100 000 persons assuming a Poisson distribution and directly age- and/or sex-standardized to the population in 2020. Individuals younger than 20 years of age with a clinical diagnosis of T1D or 10-19-year-olds with T2D were eligible for inclusion in the study.

RESULTS

The standardized T1D prevalence per 100 000 persons was 138.9 (95% CI: 137.1; 140.6) in 2002 and 245.6 (243.1; 248.0) in 2020. The standardized T2D prevalence per 100 000 persons was 3.4 (3.1; 3.8) in 2002 and 10.8 (10.1; 11.5) in 2020. The annual percent change (APC) in prevalence declined over the three periods 2002-2008/2008-2014/2014-2020 (T1D: 6.3% [3.6%; 9.0%]/3.1% [0.7%; 5.5%]/0.5% [-1.7%; 2.85], T2D: 12.3% [5.3%; 20.8%]/4.7% [-0.6%; 10.3%]/3.0% [-1.8%; 8.0%]). From 2014 to 2020, the highest APCs were observed among 15-19-year-olds (T1D: 2.5% [1.3%; 3.6%], T2D: 3.4% [-0.5%; 7.5%]).

CONCLUSIONS

The increase in diabetes prevalence has slowed, but medical care should be prepared for an increase in adolescents with diabetes.

Variation in the incidence of type 1 diabetes mellitus in children and adolescents by world region and country income group: A scoping review

INTRODUCTION

Around 18.7 million of the 537 million people with diabetes worldwide live in low-income and middle-income countries (LMIC), where there is also an increase in the number of children, adolescents, and young adults diagnosed with type 1 diabetes (T1D). There are substantial gaps in data in the current understanding of the epidemiological patterns and trends in incidence rates of T1D at the global level.

METHODS

We performed a scoping review of published studies that established the incidence of T1D in children, adolescents, and young adults aged 0-25 years at national and sub-national levels using PubMed, Embase and Global Health. Data was analyzed using R programming.

RESULTS

The scoping review identified 237 studies which included T1D incidence estimates from 92 countries, revealing substantial variability in the annual incidence of T1D by age, geographic region, and country-income classification. Highest rates were reported in the 5-9 and 10-14 year age groups than in the 0-4 and 15-19 year age groups, respectively. In the 0-14 year age group, the highest incidence was reported in Northern Europe (23.96 per 100,000), Australia/New Zealand (22.8 per 100,000), and Northern America (18.02 per 100,000), while the lowest was observed in Melanesia, Western Africa, and South America (all < 1 per 100,000). For the 0-19 year age group, the highest incidence was reported in Northern Europe (39.0 per 100,000), Northern America (20.07 per 100,000), and Northern Africa (10.1 per 100,000), while the lowest was observed in Eastern and Western Africa (< 2 per 100,000). Higher incidence rates were observed in high-income countries compared to LMICs. There was a paucity of published studies focusing on determining the incidence of T1D in LMICs.

CONCLUSION

The review reveals substantial variability in incidence rates of T1D by geographic region, country income group, and age. There is a dearth of information on T1D in LMICs, particularly in sub-Saharan Africa, where incidence remains largely unknown. Investment in population-based registries and longitudinal cohort studies could help improve the current understanding of the epidemiological trends and help inform health policy, resource allocation, and targeted interventions to enhance access to effective, efficient, equitable, and responsive healthcare services.

Does crime trigger genetic risk for type 2 diabetes in young adults? A G x E interaction study using national data

BACKGROUND

Living in neighborhoods perceived as disordered exacerbates genetic risk for type 2 diabetes (T2D) among older adults. It is unknown whether this gene-neighborhood interaction extends to younger adults. The present study aims to investigate whether crime, an objectively measured indicator of neighborhood disorder, triggers genetic risk for T2D among younger adults, and whether this hypothesized triggering occurs through exposure to obesity.

METHODS

Data were from the Wave I (2008) National Longitudinal Study of Adolescent to Adult Health. A standardized T2D polygenic score was created using 2014 GWAS meta-analysis results. Weighted mediation analyses using generalized structural equation models were conducted in a final sample of 7606 adults (age range: 25-34) to test the overall association of T2D polygenic scores with T2D, and the mediating path through obesity exposure in low, moderate, and high county crime-rate groups. Age, sex, ancestry, educational degree, household income, five genetic principal components, and county-level concentrated advantage and population density were adjusted.

RESULTS

The overall association between T2D polygenic score and T2D was not significant in low-crime areas (p = 0.453), marginally significant in moderate-crime areas (p = 0.064), and statistically significant in high-crime areas (p = 0.007). The mediating path through obesity was not significant in low or moderate crime areas (ps = 0.560 and 0.261, respectively), but was statistically significant in high-crime areas (p = 0.023). The indirect path through obesity accounted for 12% of the overall association in high-crime area.

CONCLUSION

A gene-crime interaction in T2D was observed among younger adults, and this association was partially explained by exposure to obesity.

Diabetic ketoacidosis in children with new-onset type 1 diabetes mellitus: demographics, risk factors and outcome: an 11 year review in Hong Kong

OBJECTIVES

Diabetic ketoacidosis (DKA) is a life-threatening complication of type 1 diabetes (T1D). The aim of this study is to analyze the incidence, clinical characteristics, management and outcome of children presenting with DKA in new-onset T1D from 2008 to 2018 in Hong Kong.

METHODS

Data was extracted from the Hong Kong Childhood Diabetes Registry. All subjects less than 18 years with newly diagnosed T1D from 1 January 2008 to 31 December 2018 managed in the public hospitals were included. Information on demographics, laboratory parameters, DKA-related complications and management were analyzed.

RESULTS

In the study period, there were 556 children with newly diagnosed T1D in our registry and 43.3% presented with DKA. The crude incidence rate of new-onset T1D with DKA was 1.79 per 100,000 persons/year (CI: 1.56-2.04). Subjects presenting with DKA were younger (9.5 ± 4.5 vs. 10.5 ± 4.4, p=0.01) and had shorter duration of symptoms (4.2 ± 5.9 days vs. 10.6 ± 17.1 days, p<0.01). Regarding management, up to 12.4% were given insulin boluses and 82.6% were started on insulin infusion 1 h after fluid resuscitation. The rate of cerebral edema was 0.8% and there was no mortality.

CONCLUSIONS

Younger age and shorter duration of symptoms were associated with DKA in new-onset T1D. Despite availability of international guidelines, there was inconsistency in acute DKA management. These call for a need to raise public awareness on childhood diabetes as well as standardization of practice in management of pediatric DKA in Hong Kong.

Associations between deduced first islet specific autoantibody with sex, age at diagnosis and genetic risk factors in young children with type 1 diabetes

OBJECTIVES

We aimed to further characterize demography and genetic associations of type 1 diabetes "endotypes" defined by the first appearing islet specific autoantibodies.

RESEARCH DESIGN AND METHODS

We analyzed 3277 children diagnosed before the age of 10 years from the Finnish Pediatric Diabetes Register. The most likely first autoantibody could be deduced in 1636 cases (49.9%) based on autoantibody combinations at diagnosis. Distribution of age, sex, HLA genotypes and allele frequencies of 18 single nucleotide polymorphisms (SNPs) in non-HLA risk genes were compared between the endotypes.

RESULTS

Two major groups with either glutamic acid decarboxylase (GADA) or insulin autoantibodies (IAA) as the deduced first autoantibody showed significant differences in their demographic and genetic features. Boys and children diagnosed at young age had more often IAA-initiated autoimmunity whereas GADA-initiated autoimmunity was observed more frequently in girls and in subjects diagnosed at an older age. IAA as the first autoantibody was also most common in HLA genotype groups conferring high-disease risk while GADA first was seen more evenly and frequently in HLA groups associated with lower type 1 diabetes risk. The risk alleles in IKZF4 and ERBB3 genes were associated with GADA-initiated whereas those in PTPN22, INS and PTPN2 genes were associated with IAA-initiated autoimmunity.

CONCLUSIONS

The results support the assumption that in around half of the young children the first autoantibody can be deduced based on islet autoantibody combinations at disease diagnosis. Strong differences in sex and age distributions as well as in genetic associations could be observed between GADA- and IAA-initiated autoimmunity.

The Incidence of Adult-Onset Type 1 Diabetes: A Systematic Review From 32 Countries and Regions

BACKGROUND

The epidemiology of adult-onset type 1 diabetes (T1D) incidence is not well-characterized due to the historic focus on T1D as a childhood-onset disease.

PURPOSE

We assess the incidence of adult-onset (≥20 years) T1D, by country, from available data.

DATA SOURCES

A systematic review of MEDLINE, Embase, and the gray literature, through 11 May 2021, was undertaken.

STUDY SELECTION

We included all population-based studies reporting on adult-onset T1D incidence and published from 1990 onward in English.

DATA EXTRACTION

With the search we identified 1,374 references of which 46 were included for data extraction. Estimates of annual T1D incidence were allocated into broad age categories (20-39, 40-59, ≥60, or ≥20 years) as appropriate.

DATA SYNTHESIS

Overall, we observed the following patterns: 1) there is a paucity of data, particularly in low- and middle-income countries; 2) the incidence of adult-onset T1D is lowest in Asian and highest in Nordic countries; 3) adult-onset T1D is higher in men versus women; 4) it is unclear whether adult-onset T1D incidence declines with increasing age; and 5) it is unclear whether incidence of adult-onset T1D has changed over time.

LIMITATIONS

Results are generalizable to high-income countries, and misclassification of diabetes type cannot be ruled out.

CONCLUSIONS

From available data, this systematic review suggests that the incidence of T1D in adulthood is substantial and highlights the pressing need to better distinguish T1D from T2D in adults so that we may better assess and respond to the true burden of T1D in adults.

Validation of a type 1 diabetes algorithm using electronic medical records and administrative healthcare data to study the population incidence and prevalence of type 1 diabetes in Ontario, Canada

INTRODUCTION

We aimed to develop algorithms distinguishing type 1 diabetes (T1D) from type 2 diabetes in adults ≥18 years old using primary care electronic medical record (EMRPC) and administrative healthcare data from Ontario, Canada, and to estimate T1D prevalence and incidence.

RESEARCH DESIGN AND METHODS

The reference population was a random sample of patients with diabetes in EMRPC whose charts were manually abstracted (n=5402). Algorithms were developed using classification trees, random forests, and rule-based methods, using electronic medical record (EMR) data, administrative data, or both. Algorithm performance was assessed in EMRPC. Administrative data algorithms were additionally evaluated using a diabetes clinic registry with endocrinologist-assigned diabetes type (n=29 371). Three algorithms were applied to the Ontario population to evaluate the minimum, moderate and maximum estimates of T1D prevalence and incidence rates between 2010 and 2017, and trends were analyzed using negative binomial regressions.

RESULTS

Of 5402 individuals with diabetes in EMRPC, 195 had T1D. Sensitivity, specificity, positive predictive value and negative predictive value for the best performing algorithms were 80.6% (75.9-87.2), 99.8% (99.7-100), 94.9% (92.3-98.7), and 99.3% (99.1-99.5) for EMR, 51.3% (44.0-58.5), 99.5% (99.3-99.7), 79.4% (71.2-86.1), and 98.2% (97.8-98.5) for administrative data, and 87.2% (81.7-91.5), 99.9% (99.7-100), 96.6% (92.7-98.7) and 99.5% (99.3-99.7) for combined EMR and administrative data. Administrative data algorithms had similar sensitivity and specificity in the diabetes clinic registry. Of 11 499 711 adults in Ontario in 2017, there were 24 789 (0.22%, minimum estimate) to 102 140 (0.89%, maximum estimate) with T1D. Between 2010 and 2017, the age-standardized and sex-standardized prevalence rates per 1000 person-years increased (minimum estimate 1.7 to 2.56, maximum estimate 7.48 to 9.86, p<0.0001). In contrast, incidence rates decreased (minimum estimate 0.1 to 0.04, maximum estimate 0.47 to 0.09, p<0.0001).

CONCLUSIONS

Primary care EMR and administrative data algorithms performed well in identifying T1D and demonstrated increasing T1D prevalence in Ontario. These algorithms may permit the development of large, population-based cohort studies of T1D.

Diabetic ketoacidosis in children newly diagnosed with type 1 diabetes mellitus: Role of demographic, clinical, and biochemical features along with genetic and immunological markers as risk factors. A 20-year experience in a tertiary Belgian center

BACKGROUND

Diabetic ketoacidosis (DKA) is the leading cause of morbidity and mortality in children with type 1 diabetes (T1D). Little is known about the association between genetic and immunological markers and the risk for DKA at onset of T1D. The aim of this study was to create a model foreseeing the onset of DKA in newly diagnosed patients.

METHODS

This retrospective study included 532 T1D children (aged <18 years at diagnosis) recruited in our hospital, from 1995 to 2014. DKA and its severity were defined according to the criteria of ISPAD. Genetic risk categories for developing T1D were defined according to the Belgian Diabetes Registry. Multivariate statistical analyses were applied to investigate risk factors related to DKA at diagnosis.

RESULTS

Overall 42% of patients presented DKA at diagnosis. This study outlined the major risk of DKA at diagnosis for younger children (<3 years) and for those belonging to ethnic minorities. Children carrying neutral genotypes had a 1.5-fold increased risk of DKA at diagnosis than those with susceptible or protective genotypes, a paradoxical observation not previously reported. Only solitary positive IA-2A increased the risk of DKA at diagnosis. The proposed model could help to predict the probability of DKA in 70% of newly diagnosed cases.

CONCLUSIONS

This was the first reported implication of IA-2A positivity and neutral genotypes predisposing to DKA at diagnosis regardless of its severity. Earlier diagnosis through genetic and immunological screening of high-risk children could decrease DKA incidence at diabetes onset.

Cyclical variation in the incidence of childhood-onset type 1 diabetes during 40 years in Navarra (Spain)

OBJECTIVE

To trace the evolution of type 1 diabetes (T1D) in Navarre in children under 15, between 1977 and 2016, and their characteristics at onset regarding age and sex.

SUBJECTS AND METHODS

We performed a descriptive analysis, using prospective-retrospective information. The study included all cases of T1D diagnosed in Navarre in children aged 0 to 14 years old from 1 January 1977 until 31 December 2016. The capture-recapture method was used, retrieving information from three independent sources: the five hospitals in Navarre as a primary source, and the Navarre Association of Diabetics (ANADI) and the primary healthcare system as the secondary source. Estimates and confidence intervals were calculated assuming a subjacent Poisson distribution. Chi square test was used to compare incidence between groups. The analysis of changes in incidence since 1977, adjusted for age group, sex and year of diagnosis, were evaluated with a multivariate Poisson regression model and joinpoint regression.

RESULTS

A total of 577 cases were registered resulting in a crude incidence rate of 14.99/100 000 inhabitants-year (95% confidence interval [CI]: 13.79-16.26). From 1977, the incidence has increased in cycles, reaching an incidence rate of 22.98 (95% CI: 18.52-28.21) in 2016. The relative annual increase is 3% (95% CI: 2.3-3.8). The highest incidence is in the 10 to 14 age group (P < 0.001). No differences in sex were found. The mean age at onset in children under 15 years has not changed significantly (P = 0.572).

CONCLUSIONS

The incidence of T1D in Navarre has increased 4-fold in the last four decades but is stable since 2001.

Incidence of type 1 diabetes mellitus in Navarre stabilized in the last eight years

OBJECTIVES

Incidence of type 1 diabetes mellitus raises a number of controversies. Our study aim was to contribute to answer the following questions: Is incidence of T1DM increasing? Is age at onset of type 1 diabetes mellitus decreasing? Which are the sex differences? Which are the characteristics in adults?

METHODS

A cross-sectional descriptive study using data from a primary source and 3 secondary sources from Navarre collected between 01/01/2009 and 12/31/2016. Annual incidence rates and incidence rate expressed as 100,000 person-years were estimated in the study period by age and sex group. The comparison of the sex and age incidence was made estimating the incidence rate using Poisson's regression methods. The completeness of the register was 96.08%.

RESULTS

During the 8 years analyzed, 428 new cases of type 1 diabetes mellitus were reported (incidence: 8.4/100,000 person-years, 95% CI: 7.6-9.2). Incidence has remained stable and is higher in the group under 15 years old (21.5) than in adults (5.9). Males aged 10-14 years and females aged 5-9 years were the groups with the highest incidence. Incidence then decreased with increasing age. Type 1 diabetes mellitus predominates in males aged 10-45 years, and no changes were seen in age at onset when analized by four-year periods.

CONCLUSION

Navarre shows a very high incidence of type 1 diabetes mellitus in childhood and a low incidence in adulthood. Peak incidence is seen earlier in girls, but the disease predominates in males. Neither incidence nor age at onset have changed.

Incidence and prevalence of childhood-onset Type 1 diabetes in Japan: the T1D study

AIMS

A majority of children with Type 1 diabetes in Japan are registered with the government-subsidized Specified Pediatric Chronic Disease Treatment Research Projects (SPCDTRP). In this study, the incidence and prevalence of childhood-onset (< 15 years) Type 1 diabetes in Japan were estimated by drawing on SPCDTRP data.

METHODS

Data available for 2005-2012 from the SPCDTRP and Statistics Bureau, Ministry of Internal Affairs and Communications were used to estimate the incidence of Type 1 diabetes for 2005-2010, adjusted to cover those registered within 3 years of disease onset and stratified by sex, age at onset and period of onset.

RESULTS

The incidence of Type 1 diabetes for 2005-2010 was 2.25/100,000 persons [95% confidence intervals (95% CI), 2.14-2.36] (boys: 1.91, 95% CI, 1.83-1.98; girls: 2.52, 95% CI, 2.34-2.69), with that for the age brackets 0-4, 5-9 and 10-14 years being 1.48 (95% CI, 1.29-1.66), 2.27 (95% CI, 2.08-2.47) and 3.00 (95% CI, 2.74-3.25), respectively. The onset of disease was shown to peak at age 13 among boys (3.28, 95% CI, 3.02-3.55) and at age 10 among girls (3.28, 95% CI, 3.02-3.55). The peak periods of disease onset were April/May and December. The number of children aged < 15 years with Type 1 diabetes for 2005-2012 was estimated to be 2326 (95% CI, 2202-2450) with the prevalence estimated as 13.53/100,000 persons (95% CI, 12.63-14.43).

CONCLUSIONS

Study findings demonstrated no increase in the incidence of Type 1 diabetes, although suggesting, in agreement with earlier reports, that the onset of disease peaks in adolescence with a female predominance. In addition, the incidence of childhood-onset diabetes exhibited an annual bimodal pattern in this study.

Diabetes mellitus in childhood: an emerging condition in the 21st century

The International Diabetes Federation (IDF-2015) estimates the existence of 30,900 children under 15 years old with type 1 diabetes mellitus (DM1) in Brazil, and an increase of 3.0% per year is expected. This review focused on meta-analysis and pediatric diabetes update articles in order to draw attention to the need of planning coping strategies to support this serious public health problem in coming years. DM1 is considered an immuno-mediated disease with a complex transmission influenced by genetic and environmental factors responsible for a gradual destruction of the insulin producing pancreatic beta cells. Seroconversion to DM1-associated autoantibodies and abnormalities in metabolic tests that assess insulin secretion and glucose tolerance can be used as predictive criteria of beta cells functional reserve and the onset of the clinical disease. Symptomatic DM1 treatment is complex and the maintenance of good metabolic control is still the only effective strategy for preserving beta cell function. Disease duration and hyperglycemia are both risk factors for the onset of chronic vascular complications that negatively affect the quality of life and survival of these patients. In this regard, health teams must be trained to provide the best possible information on pediatric diabetes, through continuing education programs focused on enabling these young people and their families to diabetes self-management.

Genetic and environmental factors affect the onset of type 1 diabetes mellitus

BACKGROUND

Type 1 diabetes mellitus (T1DM) is influenced by genetic as well as environmental factors. Its incidence has risen considerably since the 1950s.

OBJECTIVE

This study investigates T1DM time trends from 1989 to 2008 and tries to establish whether breast/bottle feeding, a family history of diabetes, and childhood infectious diseases influence age at onset.

METHODS

The study used the population-based registry of childhood diabetes of Abruzzo (central Italy), which includes incident cases of patients aged less than 15 yr. The pooled 1989-2008 global ascertainment of the registry was 95%. The trend was estimated using age-period-cohort models RESULTS: Overall standardized incidence rates (SIR) increased by 73.38% from 8.94 (1989-1993) to 15.50 (2004-2008). A rising trend was found in all age groups; annual rises were significant for the overall population (3.40%, p < 0.01) and for 5-9 yr olds (5.48%, p < 0.01). SIR increased in males by 106.26%, from 9.26 in 1989-1993 to 19.10 in 2004-2008. Early T1DM onset was related to mixed feeding (6.80 yr ± 3.58 vs 8.20 ± 3.81 yr; p = 0.002), and a family history of T1DM (6.71 ± 3.96 yr vs. 8.09 ± 3.77 yr; p = 0.014), whereas multiple infections delayed age at onset (9.71 ± 2.37 yr vs 7.71 ± 2.82 yr; p = 0.03).

CONCLUSIONS

T1DM incidence exhibits a rising time trend that is particularly evident in males and in middle age group; mixed feeding and a family history of diabetes are associated with early onset, multiple bacterial infections contracted before diabetes are associated with a significant delay.

Lactobacillus salivarius reverse diabetes-induced intestinal defense impairment in mice through non-defensin protein

Altered intestinal microbiota and subsequent endotoxemia play pathogenic roles in diabetes. We aimed to study the mechanisms of intestinal defense impairment in type 1 diabetes and the effects of Lactobacillus salivarius as well as fructooligosaccharides (FOS) supplementation on diabetes-induced bacterial translocation. Alterations in the enteric microbiome, expression of mucosal antibacterial proteins and bacteria-killing activity of the intestinal mucosa in streptozotocin (STZ)-induced diabetic mice and Ins2(Akita) mice were investigated. The effects of dead L. salivarius (2×10(8)CFU/ml) and FOS (250 mg per day) supplementation for 1 week on endotoxin levels and Klebsiella pneumoniae translocation were also examined. Finally, germ-free mice were cohoused with wild-type or Ins2(Akita) mice for 2 weeks to examine the contribution of microbiota on the antibacterial protein expression. STZ-induced diabetic mice developed intestinal defense impairment as demonstrated by decreased mucosal bacteria-killing activity; reduction of non-defensin family proteins, such as Reg3β, Reg3γ, CRP-ductin and RELMβ, but not the defensin family proteins; and increased bacterial translocation. Intestinal bacteria overgrowth, enteric dysbiosis and increased intestinal bacterial translocation, particularly pathogenic K. pneumoniae in STZ-induced diabetic mice and Ins2(Akita) mice, were noted. Treating diabetic mice with dead L. salivarius or FOS reversed enteric dysbiosis, restored mucosal antibacterial protein and lessened endotoxin levels as well as K. pneumoniae translocation. Moreover, germ-free mice cohoused with wild-type mice demonstrated more intestinal Reg3β and RELMβ expression than those cohoused with Ins2(Akita) mice. These results indicate that hyperglycemia induces enteric dysbiosis, reduction of non-defensin proteins as well as bacteria-killing activity of the intestinal mucosa and intestinal defense impairment. Reversal of enteric dysbiosis with dead L. salivarius or FOS supplementation decreases diabetes-induced K. pneumoniae translocation and endotoxin levels through the induction of non-defensin proteins.

Incidence of type 1 diabetes in age groups above 15 years: facts, hypothesis and prospects for future epidemiologic research

Although onset of type 1 diabetes can occur in adulthood, epidemiological data are scarce, limiting our potential to identify unknown determinants of the disease. Paucity of registries expanding the recruitment of incident cases up to adulthood, atypical clinical features of type 1 diabetes at onset, misclassification of type 1 as type 2 diabetes and little use of markers of β-cell autoimmunity represents major obstacles in studying the risk of type 1 diabetes in adults. New strategies in study design, data collection and analyses may overcome these problems in the future. Population-based surveys and registries including adulthood; use of etiological rather than clinical criteria to define type 1 diabetes; availability of electronic health records as prescription data sources to avoid missing data; and application of proper statistical methods will be instrumental to gain better insight on the epidemiology and natural history of the disease.

Excess cardiovascular risk in diabetic women: a case for intensive treatment

Diabetes is a common and rapidly growing disease that affects more than 380 million people worldwide and is an established risk factor for cardiovascular disease with differential effects on women compared to men. While the general population of women, particularly young women, has more favourable cardiovascular risk profiles than men, this protective effect has been shown to be lost or even reversed in diabetic women. Several studies have demonstrated a significant diabetes-associated excess risk of cardiovascular disease in women. Sex-specific differences in risk factors associated with diabetes and their management may be responsible for the relative excess cardiovascular risk in women with diabetes. Diabetic women need intensive treatment in order to optimize management of cardiovascular risk factors. Further studies are needed to elucidate the mechanisms underlying the excess cardiovascular risk in diabetic women in order to tailor prevention and treatment strategies.

The prevalence of type 1 diabetes mellitus among 15-34-year-aged Lithuanian inhabitants during 1991-2010

AIMS

To summarize the data on the prevalence of type 1 diabetes mellitus among 15-34-year-aged Lithuania inhabitants (1991-2010).

METHODS

New prevalent cases consist of growing-up patients with diabetes onset in childhood, i.e., up to 14 years, new onset 15-34-year-aged type 1 diabetic patients Lithuanian inhabitants, and immigrants. The data on type 1 diabetes was collected with the help of general practitioners and regional endocrinologists in Lithuania.

RESULTS

On 31 December 1991, there were 1202 adolescent and adult 15-34-year-aged patients with type 1 diabetes mellitus or 103.59 per 100,000 inhabitants of the same age group (95% Poisson CI 97.90-109.62), and at the end of 2010 - 1533 or 187.80 (178.63-197.44), respectively in Lithuania. During 19-year period the mean increase of type 1 diabetic patients was 1.25±1.94% per year or 1.47±2.74 per 100,000 inhabitants per mean year of the study period (for males 1.42±2.14% or 1.69±3.05/100,000 and for females 1.05±1.99%, or 1.24±2.92/100,000). Regression-based linear trends showed that the prevalence of type 1 diabetes mellitus in 15-34-year-age group had a tendency to increase among males (r=0.953; p<0.001) and females (r=0.970; p<0.001). The age adjusted prevalence frequencies for males and females in 1991 were correspondingly 102.81/100,000 and 104.55/100,000, and in 2010 - 193.75 and 182.01.

CONCLUSION

The prevalence of type 1 diabetes mellitus among 15-34-year-age males and females had a tendency to increase during 1991-2010.

Global epidemiology of type 1 diabetes in young adults and adults: a systematic review

Background

Although type 1 diabetes (T1D) can affect patients of all ages, most epidemiological studies of T1D focus on disease forms with clinical diagnosis during childhood and adolescence. Clinically, adult T1D is difficult to discriminate from certain forms of Type 2 Diabetes (T2D) and from Latent Autoimmune Diabetes in Adults (LADA).

We searched the information available worldwide on the incidence of T1D among individuals over 15 years of age, and which diagnostic criteria should be used use to qualify T1D in adults. We then studied the variation of T1D incidence with age in adults, and compared it to the incidence in the <15 years-old.

Methods

A systematic review of the literature was performed to retrieve original papers in English, French and Spanish published up to November 6, 2014, reporting the incidence of T1D among individuals aged over 15 years. The study was carried out according to the PRISMA recommendations.

Results

We retrieved information reporting incidence of T1D among individuals aged more than 15 years in 35 countries, and published in 70 articles between 1982 and 2014. Specific anti-beta-cell proteins or C-peptide detection were performed in 14 of 70 articles (20%). The most frequent diagnostic criteria used were clinical symptoms and immediate insulin therapy. Country-to-country variations of incidence in those aged >15 years paralleled those of children in all age groups. T1D incidence was larger in males than in females in 44 of the 54 (81%) studies reporting incidence by sex in people >15 years of age. The overall mean male-to-female ratio in the review was 1.47 (95% CI = 1.33-1.60, SD = 0.49, n = 54, p = <0.0001). Overall, T1D incidence decreased in adulthood, after the age of 14 years.

Conclusions

Few studies on epidemiology of T1D in adults are available worldwide, as compared to those reporting on children with T1D. The geographical variations of T1D incidence in adults parallel those reported in children. As opposed to what is known in children, the incidence is generally larger in males than in females. There is an unmet need to evaluate the incidence of autoimmune T1D in adults, using specific autoantibody detection, and to better analyze epidemiological specificities – if any – of adult T1D.

PROSPERO registration number

CRD42012002369.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-1591-y) contains supplementary material, which is available to authorized users.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Male-female differences in diabetic retinopathy?

The purpose of this paper is to review male-female differences in the incidence and prevalence of diabetes and diabetic retinopathy. These differences will be established primarily through results from our present research and a review of related literature. Previously, we have demonstrated that neuroretinal dysfunction can be used to predict the location of future retinopathy up to three years before it is manifest. Our current research suggests that, for type 2 diabetes, the normal differences in neuroretinal function between nondiabetic males and females under 50 years of age are altered in patients with type 2 diabetes. Furthermore, local neuroretinal function in type 2 diabetes is more abnormal in adult males compared with adult females. The literature also suggests that there are male-female differences in the occurrence of diabetes. In adolescence, the incidence of type 1 diabetes is greater in males, whereas in type 2 diabetes, the incidence is greater in females. This excess of females in type 2 diabetes shifts to a more equal incidence between the two sexes in adults. In addition, advanced retinopathy in type 1 diabetes appears to be more common in males, and the presence and severity of diabetic retinopathy at the time of diagnosis in type 2 diabetes appears to be more associated with male sex. Although the reasons for male-female differences identified in this review are unknown, sex appears to be a significant factor in certain aspects of diabetes incidence and diabetic retinopathy.

Aberrant gut microbiota composition at the onset of type 1 diabetes in young children

AIMS/HYPOTHESIS

Recent studies indicate that an aberrant gut microbiota is associated with the development of type 1 diabetes, yet little is known about the microbiota in children who have diabetes at an early age. To this end, the microbiota of children aged 1-5 years with new-onset type 1 diabetes was compared with the microbiota of age-matched healthy controls.

METHODS

A deep global analysis of the gut microbiota composition was established by phylogenetic microarray analysis using a Human Intestinal Tract Chip (HITChip).

RESULTS

Principal component analyses highlighted the importance of age when comparing age-matched pairs. In pairs younger than 2.9 years, the combined abundance of the class Bacilli (notably streptococci) and the phylum Bacteroidetes was higher in diabetic children, whereas the combined abundance of members of Clostridium clusters IV and XIVa was higher in the healthy controls. Controls older than 2.9 years were characterised by a higher fraction of butyrate-producing species within Clostridium clusters IV and XIVa than was seen in the corresponding diabetic children or in children from the younger age groups, while the diabetic children older than 2.9 years could be differentiated by having an increased microbial diversity.

CONCLUSIONS/INTERPRETATION

The results from both age groups suggest that non-diabetic children have a more balanced microbiota in which butyrate-producing species appear to hold a pivotal position.

The incidence of diabetes among 0-34 year olds in Sweden: new data and better methods

AIMS/HYPOTHESIS

We reassessed the validity of previously reported incidence rates for type 1 diabetes in 0-34 year olds in Sweden. We estimated new incidence rates through three nationwide registers.

METHODS

We used capture-recapture methods to assess ascertainment in the Diabetes Incidence Study in Sweden (DISS) and estimated incidence rates in the 20-34 year age group for 2007-2009. We examined whether incidence rates in patients aged 34 and younger could be estimated through the Prescribed Drug Register (PDR) via a proxy for diagnosis of type 1 diabetes; men with at least one and women with at least three prescriptions for insulin were included if they had not been given oral glucose-lowering drugs. We scrutinised the proxy by comparing incidence rates in patients aged 14 and younger with the Swedish Childhood Diabetes Register (SCDR), which has 95-99% ascertainment, and by assessing diabetes type among 18-34 year olds in the National Diabetes Register (NDR).

RESULTS

Incidence rates were two to three times higher than previously reported. The absolute number of cases (2007-2009, age 20-34) was 435 in the DISS, 923 in the NDR, 1,217 in the PDR, 1,431 in all three and 1,617 per the capture-recapture method. Ascertainment in the DISS was ~29% for 2007-2009. The proxy diagnosis in the PDR was highly reliable, while the capture-recapture method presumably generated an overestimate.

CONCLUSIONS/INTERPRETATION

The incidence of type 1 diabetes in patients aged 34 and younger was two to three times higher than previously reported. The PDR can be used to reliably assess incidence rates in this age group.

Diabetes in the young - a global view and worldwide estimates of numbers of children with type 1 diabetes

This paper describes the methodology, results and limitations of the 2013 International Diabetes Federation (IDF) Atlas (6th edition) estimates of the worldwide numbers of prevalent cases of type 1 diabetes in children (<15 years). The majority of relevant information in the published literature is in the form of incidence rates derived from registers of newly diagnosed cases. Studies were graded on quality criteria and, if no information was available in the published literature, extrapolation was used to assign a country the rate from an adjacent country with similar characteristics. Prevalence rates were then derived from these incidence rates and applied to United Nations 2012 Revision population estimates for 2013 for each country to obtain estimates of the number of prevalent cases. Data availability was highest for the countries in Europe (76%) and lowest for the countries in sub-Saharan Africa (8%). The prevalence estimates indicate that there are almost 500,000 children aged under 15 years with type 1 diabetes worldwide, the largest numbers being in Europe (129,000) and North America (108,700). Countries with the highest estimated numbers of new cases annually were the United States (13,000), India (10,900) and Brazil (5000). Compared with the prevalence estimates made in previous editions of the IDF Diabetes Atlas, the numbers have increased in most of the IDF Regions, often reflecting the incidence rate increases that have been well-documented in many countries. Monogenic diabetes is increasingly being recognised among those with clinical features of type 1 or type 2 diabetes as genetic studies become available, but population-based data on incidence and prevalence show wide variation due to lack of standardisation in the studies. Similarly, studies on type 2 diabetes in childhood suggest increased incidence and prevalence in many countries, especially in Indigenous peoples and ethnic minorities, but detailed population-based studies remain limited.

The emerging global epidemic of type 1 diabetes

Type 1 diabetes mellitus (T1D) can occur at any age, with a peak in incidence around puberty. Classification between T1D and type 2 diabetes becomes more challenging with increasing age of onset of T1D over time develops in genetically predisposed individuals. The main susceptibility is conferred with human leukocyte antigen (HLA) genes. Some of the geographic variation in incidence and familial aggregation is explained by differences in HLA haplotypes. In many populations, the incidence is somewhat higher in males than in females, and a 1.3- to 2.0-fold male excess in incidence after about 15 years of age exists in most populations. The incidence of childhood-onset T1D varies markedly among countries. East Asian and native American populations have low incidences (approximately 0.1-8 per 100 000/year), while the highest rates are found in Finland (>60 per 100 000/year), Sardinia (40 per 100 000/year), and Sweden (47 per 100 000/year). The risk is highest in European-derived populations. About 10 %-20 % of newly diagnosed childhood cases of T1D have an affected first-degree relative. Those with an affected sibling or parent have a cumulative risk of 3 %-7 % up to about 20 years of age, as compared with <1 % in the general population. The cumulative incidence among the monozygotic co-twins of persons with T1D is less than 50 %. Thus, the majority of genetically predisposed people do not develop T1D. Studies assessing temporal trends have shown that the incidence of childhood-onset T1D has increased in all parts of the world. The average relative increase is 3 %-4 % per calendar year. For instance, in Finland, the incidence today is 5 times higher than 60 years ago. At the same time, the age at onset of T1D in children has become younger. It is strongly believed that nongenetic factors are important for the development of T1D and its increase, but the causative evidence is missing. The causes for this increasing trend and current epidemic still remain unknown.

The trends and the risk of type 1 diabetes over the past 40 years: an analysis by birth cohorts and by parental migration background in Sweden

OBJECTIVE

To investigate the trends and the risk of developing type 1 diabetes in the offspring of Swedes and immigrants by specific parental migration background, age, sex and birth cohort.

DESIGN

Registry-based cohort study.

SETTING

Using Swedish nationwide data we analysed the risk of developing type 1 diabetes in 3 457 486 female and 3 641 304 male offspring between 0 and 30 years of age, born to native Swedes or immigrants and born and living in Sweden between 1969 and 2009. We estimated incidence rate ratios (IRRs) with 95% CIs using Poisson regression models. We further calculated age-standardised rates (ASRs) of type 1 diabetes, using the world population as standard.

RESULTS

We observed a trend of increasing ASRs among offspring below 15 years of age born to native Swedes and a less evident increase among offspring of immigrants. We further observed a shift towards a younger age at diagnosis in younger birth cohorts in both groups of offspring.Compared with offspring of Swedes, children (0-14 years) and young adults (15-30 years) with one parent born abroad had an overall 30% and 15-20% lower IRR, respectively, after multivariable adjustment. The reduction in IRR was even greater among offspring of immigrants if both parents were born abroad. Analysis by specific parental region of birth revealed a 45-60% higher IRR among male and female offspring aged 0-30 years of Eastern Africa.

CONCLUSIONS

Parental country of birth and early exposures to environmental factors play an important role in the aetiology of type 1 diabetes.

The incidence of type 1 diabetes in Republic of Srpska (Bosnia and Herzegovina) and Slovenia in the period 1998-2010

OBJECTIVE

To establish and compare the incidence and trends of type 1 diabetes mellitus (T1DM) in Republic of Srpska and Slovenia in age group 0-18 yr from 1998 to 2010.

METHODS

The subjects (413 newly diagnosed T1DM patients in the Republic of Srpska and 664 in Slovenia) were grouped into the age groups: 0-4, 5-9, 10-14, and 15-18 yr. Confidence intervals (CI) for crude incidence rates were estimated assuming numbers of cases were counts from the Poisson distribution. Gender and age-specific standardization was done according to the EURODIAB criteria. Statistical analysis used Poisson-regression models to analyze difference rate between countries and to investigate the incidence trend.

RESULTS

Case ascertainment was estimated to be 99.95% for the Republic of Srpska and 100% for Slovenia by using the capture-recapture method. The standardized incidence of T1DM for age group 0-18 yr in the Republic of Srpska was 7.5/100 000/yr (95% CI: 6.8-8.3). For the same period and the same age group incidence in Slovenia was 12.5/100 000/yr (95% CI: 11.5-13.5). Annual increase in the incidence in the Republic of Srpska was 2.3% (95% CI: -0.3 to 5.0%), whereas in Slovenia 4.3% (95% CI: 2.2-6.5%).

CONCLUSION

The incidence for age group 0-18 yr standardized to the world population is remarkably higher in Slovenia than in the Republic of Srpska. Further follow-up and investigations are needed to explain the high difference in incidence of T1DM between the two geographically related countries.

[Differences by age and gender in the incidence of type 1 diabetes in Navarre, Spain (2009-2011)]

OBJECTIVE

To determine the incidence of type 1 diabetes in Navarre, irrespective of age, from 2009 to 2011, and its characteristics at onset by age and gender.

METHOD

A descriptive cross-sectional study was conducted. Data were obtained from one primary and three secondary sources. Poisson regression models were used to analyze differences in incidence rates among age groups and between male and female patients.

RESULTS

We detected 167 new cases (incidence: 8.7/100,000 inhabitants-year; 95%CI: 7.4-10.1). The incidence was higher in children than in adults and was highest in the group aged 10-14 years. The incidence was higher in males than in females. The incidence increased with age in boys under 15 years but not in girls.

CONCLUSIONS

The incidence of type 1 diabetes in children and young adults in Navarre is among the highest in Europe. Differences were found by age and gender.

Beta cell function and BMI in ethnically diverse children with newly diagnosed autoimmune type 1 diabetes

OBJECTIVE

To examine the relationship between BMI and beta-cell function at diagnosis of autoimmune type 1 diabetes (T1D) in a large group of ethnically diverse children.

METHODS

Cross-sectional analysis of 524 children (60.8% White, 19.5% Hispanic, 14.5% African-American, 5.2% other non-Hispanic; mean age = 9.8 yr [SD = 2.5]) with newly diagnosed autoimmune T1D.

RESULTS

As much as 22.2% of children were overweight or obese. Median random serum C-peptide was 0.40 ng/mL (25th-75th percentiles = 0.3-0.8), with median glycemia of 366 mg/dL (25th-75th percentiles = 271-505). Median C-peptide was 0.3, 0.5, 0.7, and 0.85 ng/mL, respectively, in underweight, normal weight, overweight, and obese children (p < 0.0001, Kruskal-Wallis). In the final model (p < 0.0001), the odds of having preserved C-peptide (≥0.6 ng/mL) were increased by 2.4-fold (95% CI = 1.2-4.9, p < 0.015) and 4.1-fold (1.9-8.5, p < 0.0001), respectively, in overweight and obese compared to lean children; 1.3-fold per each year of age; 2.5-fold in girls compared to boys; 4-fold in children who presented without, compared to with, diabetes ketoacidosis (DKA); and decreased by 21% for each point increase in HbA1c. Tanner stage, race/ethnicity, glycemia, and number of anti-islet antibodies expressed were not independently associated with preserved C-peptide. The association between BMI and C-peptide levels was significant in children with and without preserved C-peptide. Excluding patients who presented with DKA and/or using BMI obtained 5 wk after diagnosis did not alter the results.

CONCLUSION

Obese and overweight children compared to lean children have greater beta-cell function at the onset of autoimmune T1D. Prospective studies on the relationships among BMI, beta-cell function, and progression to clinical T1D are warranted.

Self-classification as an adult in patients with type 1 diabetes: relationships with glycemic control and illness coping

OBJECTIVE

Previous community research has demonstrated the link between adult self-classification and health behaviors. The present study investigated the extent to which individuals with type 1 diabetes (ages 18-30 years) classified themselves as adults as compared with individuals without diabetes. Adult self-classification was examined in relation to illness coping and glycemic control.

METHODS

A total of 194 patients and 287 control individuals participated. Adult self-classification was assessed using a single item, coping was assessed using the Diabetes Coping Measure, and glycemic control was determined by HbA(1c) values.

RESULTS

Compared with control participants, more patients classified themselves as adults. Furthermore, adult self-classification was positively related to glycemic control. Structural equation modeling indicated that coping mediated the relationship between adult self-classification and glycemic control.

CONCLUSION

Individuals with diabetes classified themselves as adults more often than did their peers without diabetes, possibly due to their need to master their lives when confronted with diabetes. Adult self-classification appeared to function as a resource for glycemic control through its relationship with specific coping strategies.

PRACTICE IMPLICATIONS

The present study underscores the need to assess adult self-classification in individuals with diabetes. Our findings call for a developmentally tailored transition from pediatric to adult care.

The incidence of type 1 diabetes mellitus among 15-34 years aged Lithuanian population: 18-year incidence study based on prospective databases

Background

The aim of this prospective study was to determine the incidence of type 1 diabetes mellitus in 15-34-year-aged Lithuanian males and females during 1991 - 2008

Methods

A contact system with general practitioners covering 100% of the 15-34-year-aged Lithuanian population was the primary data source. Reports from regional endocrinologists and statistical note-marks of State patient insurance fund served as secondary sources for case ascertainment.

Results

The average age-standardized incidence rate was 8.30 per 100,000 persons per year (95% Poisson distribution confidence interval [CI] 7.90-8.71) during 1991 - 2008 and was statistically significantly higher among males (10.44 per 100,000 persons per year, 95% CI 9.82-11.10) in comparison with females (6.10 per 100,000, 95% CI 5.62-6.62). Male/female rate ratio was 1.71 (95% CI 1.63-1.80). Results of the linear 1991 - 2008 regression model showed that the incidence of Type 1 diabetes in 15-34-year-aged males and females decreased slightly over the time (r = -0.215, p > 0.05).

Conclusions

Our data demonstrated the male predominance in primary incidence of type 1 diabetes mellitus in 15-34-year-aged population in Lithuania. The incidence of type 1 diabetes mellitus in 15-34-year-aged males and females decreased slightly during 1991-2008.

Incidence of type 1 diabetes in Sweden among individuals aged 0-34 years, 1983-2007: an analysis of time trends

OBJECTIVE

To clarify whether the increase in childhood type 1 diabetes is mirrored by a decrease in older age-groups, resulting in younger age at diagnosis.

RESEARCH DESIGN AND METHODS

We used data from two prospective research registers, the Swedish Childhood Diabetes Register, which included case subjects aged 0-14.9 years at diagnosis, and the Diabetes in Sweden Study, which included case subjects aged 15-34.9 years at diagnosis, covering birth cohorts between 1948 and 2007. The total database included 20,249 individuals with diabetes diagnosed between 1983 and 2007. Incidence rates over time were analyzed using Poisson regression models.

RESULTS

The overall yearly incidence rose to a peak of 42.3 per 100,000 person-years in male subjects aged 10-14 years and to a peak of 37.1 per 100,000 person-years in female subjects aged 5-9 years and decreased thereafter. There was a significant increase by calendar year in both sexes in the three age-groups <15 years; however, there were significant decreases in the older age-groups (25- to 29-years and 30- to 34-years age-groups). Poisson regression analyses showed that a cohort effect seemed to dominate over a time-period effect.

CONCLUSIONS

Twenty-five years of prospective nationwide incidence registration demonstrates a clear shift to younger age at onset rather than a uniform increase in incidence rates across all age-groups. The dominance of cohort effects over period effects suggests that exposures affecting young children may be responsible for the increasing incidence in the younger age-groups.

Immune and cell therapy in type 1 diabetes: too little too late?

INTRODUCTION

Type 1 diabetes is caused by autoimmune destruction of insulin-producing β-cells. Intensive insulin therapy protects most patients against chronic complications of diabetes, but exposes patients to acute complications like hypoglycaemia and impacts on quality of life. Therapies that aim at protecting or restoring endogenous insulin secretion might help in decreasing the risk of severe hypoglycemia and long-term complications.

AREAS COVERED

This article reviews the literature of clinical immunotherapy and β-cell transplantation in treatment of type 1 diabetes with specific focus on the effect on preserving and restoring β-cell mass.

EXPERT OPINION

Several studies in recent-onset type 1 diabetic patients have provided proof of principle that immunotherapy can preserve residual functional β-cell mass. The observation that this strategy is most effective early in the disease process opens possibilities of arresting and even preventing type 1 diabetes. In patients with too few or no surviving β-cells, current protocols of β-cell transplantation can restore functional β-cell mass up to 25% of levels in healthy controls. Unfortunately, both strategies to date are followed by progressive decline of endogenous insulin secretion later on. Strategies to restore functional β-cell mass to a higher level and to restore immune tolerance are thus needed.

Thirty years of prospective nationwide incidence of childhood type 1 diabetes: the accelerating increase by time tends to level off in Sweden

OBJECTIVE

During the past few decades, a rapidly increasing incidence of childhood type 1 diabetes (T1D) has been reported from many parts of the world. The change over time has been partly explained by changes in lifestyle causing rapid early growth and weight development. The current study models and analyzes the time trend by age, sex, and birth cohort in an exceptionally large study group.

RESEARCH DESIGN AND METHODS

The present analysis involved 14,721 incident cases of T1D with an onset of 0-14.9 years that were recorded in the nationwide Swedish Childhood Diabetes Registry from 1978 to 2007. Data were analyzed using generalized additive models.

RESULTS

Age- and sex-specific incidence rates varied from 21.6 (95% CI 19.4-23.9) during 1978-1980 to 43.9 (95% CI 40.7-47.3) during 2005-2007. Cumulative incidence by birth cohort shifted to a younger age at onset during the first 22 years, but from the birth year 2000 a statistically significant reversed trend (P < 0.01) was seen.

CONCLUSIONS

Childhood T1D increased dramatically and shifted to a younger age at onset the first 22 years of the study period. We report a reversed trend, starting in 2000, indicating a change in nongenetic risk factors affecting specifically young children.

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

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

Association between childhood obesity and subsequent Type 1 diabetes: a systematic review and meta-analysis

AIMS

To review and synthesize the published evidence on the possible association between childhood obesity and the subsequent risk of Type 1 diabetes.

METHODS

The PubMed database was systematically searched for studies using childhood obesity, BMI or %weight-for-height as the exposure variable and subsequent Type 1 diabetes as the outcome. Studies were only included if assessment of obesity preceded the diagnosis of Type 1 diabetes.

RESULTS

Eight case-control studies and one cohort study were included, comprising a total of 2658 cases. Of these nine studies, seven reported a significant association between childhood obesity, BMI or %weight-for-height and increased risk for Type 1 diabetes. Meta-analysis of the four studies that reported childhood obesity as a categorical exposure produced a pooled odds ratio of 2.03 (95% CI 1.46-2.80) for subsequent Type 1 diabetes; however, in those studies, age at obesity assessment varied from age 1 to 12 years. A dose-response relationship was supported by a continuous association between childhood BMI and subsequent Type 1 diabetes in a meta-analysis of five studies (pooled odds ratio 1.25 (95%CI 1.04-1.51) per 1 sd higher BMI).

CONCLUSION

There is overall evidence for an association between childhood obesity, or higher BMI, and increased risk of subsequent Type 1 diabetes. Several theories have been proposed for a causal relationship. Reduction in Type 1 diabetes should be considered as a potential additional benefit of preventing childhood obesity.

Epidemiology of type 1 diabetes

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

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.

Increasing incidence of childhood-onset type 1 diabetes mellitus among Estonian children in 1999-2006. Time trend analysis 1983-2006

BACKGROUND

The incidence of childhood-onset type 1 diabetes mellitus (T1DM) among Estonian children under 15 years of age was 10.1 per 100,000 per year in 1983-1990 and 12.2 per 100,000 per year in 1991-1998 with the highest incidence in age-group 10.0-14.9 years in both periods. From 1983 to 1998, the incidence increased most rapidly in age-group 0-4.9 years.

OBJECTIVE

To determine the incidence of T1DM among Estonian children in 1999-2006 and to compare the results with the data from 1983 to 1998.

SUBJECTS AND METHODS

In 1999-2006, population-based incidence data were collected from two centers where all children with T1DM are seen after the diagnosis. Data for earlier periods were obtained from previously published data. Subjects were divided into three age-groups: 0-4.9 years, 5.0-9.9 years and 10.0-14.9 years.

RESULTS

Between 1999 and 2006, 310 new cases of T1DM were diagnosed in Estonian children aged 0-14.9 years. The age-standardized incidence rate for that period was 17.2 [95% confidence interval (CI) 13.1-21.2]. The incidence was the highest, 21.2 (95% CI 17.7-25.3) in age-group 5.0-9.9 years. Over the time period 1983-2006, the incidence of childhood-onset T1DM in Estonian children under 15 years of age increased annually by an average 3.3% with the most rapid annual increase-9.3%-occurring in the youngest age-group.

CONCLUSIONS

The incidence of childhood-onset T1DM in Estonia continues to rise and the age of onset of the disease becomes younger.

Epidemiological perspectives on type 1 diabetes in childhood and adolescence in germany: 20 years of the Baden-württemberg Diabetes Incidence Registry (DIARY)

OBJECTIVE

To predict the frequency of type 1 diabetes in childhood and adolescence (<15 years of age) in Germany for the next 20 years.

RESEARCH DESIGN AND METHODS

Data on diabetes onset has been collected by means of a registry in the federal German state of Baden-Württemberg (documentation period, 1987-2006; n = 5,108; completeness of data 98.1%).

RESULTS

The current incidence rate (2000-2006) is 19.4 per 100,000 per year (95% CI 18.6-20.2). The annual incidence rate can be expressed as a square of a linear function of the calendar year X [y = (3.05 + 0.0778 x {X-1986})(2); r(2) = 0.90]. The highest increase per year was observed in the age-groups comprising 2- and 3-year-olds (12 and 13% per year, respectively). The incidence rate for the year 2026 is estimated to be 37.9 per 100,000 per year (95% CI 33.3-42.9).

CONCLUSIONS

The increase that we found in younger children is characteristic of a left shift toward an earlier age.

The geoepidemiology of type 1 diabetes

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