Marked temporal increase in the incidence of type 1 and type 2 diabetes among young adults in Finland

Association of Killer Cell Immunoglobulin-Like Receptors and Their HLA-Ligands with Type 1 Diabetes Among South Indian Population

BACKGROUND

Type 1 diabetes (T1D) is a multifactorial autoimmune disease, involving strong genetic components with familial predisposition. Killer cell immunoglobulin-like receptors (KIRs) found on the surface of NK cells have ligands of human leukocyte antigen (HLA) class I that are associated with T1D. The present study evaluates the influence of KIR genes and their HLA-ligands in the aetiology of T1D among the South Indian population.

METHODS

A total of 125 T1D patients, along with their parents (n = 126) and siblings (n = 52) were recruited. PCR-based genotyping was performed for KIR genes and HLA class I ligands. The gene frequencies were compared between patients and siblings/parents. Linkage-disequilibrium (LD) analysis was performed to assess the genetic association between KIR gene pairs.

RESULTS

The results show significant differences in HLA-ligands of KIR genes between patients and parents. The HLA-C1C1 homozygosity was found to be a predisposing risk factor, and HLA-C1C2 heterozygosity was protective towards T1D along with either the activating KIR2DS2 or inhibitory KIRs 2DL1, 2DL2, 2DL3. However, the frequency of inhibitory KIR3DL1 significantly increased in the presence of HLA-B Bw4 Ile80 in parents when compared to patients showing a protective effect on T1D. Two pairs of KIR genes, 2DS4-3DL1 and 2DS1-2DL5, showed strong LD in patients, siblings and parents.

CONCLUSION

The KIR-HLA ligand combinations have a significant effect on T1D aetiology among the South Indian population. This study defines a pattern for family-based association studies with genotypic information about KIR genes and their HLA-ligands, providing the first evidence towards T1D among the South Indian population.

Waist-Height Ratio and the Risk of Severe Diabetic Eye Disease in Type 1 Diabetes: A 15-Year Cohort Study

CONTEXT

Obesity prevalence has increased in type 1 diabetes (T1D). However, the relationship between body composition and severe diabetic eye disease (SDED) is unknown.

OBJECTIVE

To investigate the associations between body composition and SDED in adults with T1D.

METHODS

From 5401 adults with T1D in the Finnish Diabetic Nephropathy Study, we assessed 3468, and 437 underwent dual-energy X-ray absorptiometry for body composition analysis. The composite outcome was SDED, defined as proliferative retinopathy, laser treatment, antivascular endothelial growth factor treatment, diabetic maculopathy, vitreous hemorrhage, and vitrectomy. Logistic regression analysis evaluated the associations between body composition and SDED. Multivariable Cox regression analysis assessed the associations between the anthropometric measures and SDED. Subgroup analysis was performed by stages of albuminuria. The relevance ranking of each variable was based on the z statistic.

RESULTS

During a median follow-up of 14.5 (interquartile range 7.8-17.5) years, 886 SDED events occurred. Visceral/android fat ratio was associated with SDED [odds ratio (OR) 1.40, z = 3.13], as well as the percentages of visceral (OR 1.80, z = 2.45) and android fat (OR 1.28, z = 2.08) but not the total body fat percentage. Waist-height ratio (WHtR) showed the strongest association with the SDED risk [hazard ratio (HR) = 1.28, z = 3.73], followed by the waist (HR 1.01, z = 3.03), body mass index (HR 1.03, z = 2.33), and waist-hip ratio (HR 1.15, z = 2.22). The results were similar in normo- and microalbuminuria but not significant in macroalbuminuria. A WHtR ≥ 0.5 increased the SDED risk by 28% at the normo- and microalbuminuria stages.

CONCLUSIONS

WHtR, a hallmark of central obesity, is associated with SDED in individuals with T1D.

Incidence trend of type 1 diabetes mellitus in Serbia

BACKGROUND

The incidence of type 1 diabetes mellitus (T1DM) increased worldwide. The objective of the paper was to compare the incidence trend of T1DM in children and adolescents aged 0-19 and in adults under 30 years of age in Serbia from 2006 to 2017. Additional aim was to compare incidence rates of T1DM and type 2 diabetes mellitus (T2DM) among adults aged 20-24 and 25-29 years of age.

METHODS

Trends and annual percentage change (APC) of the incidence rate with corresponding 95% confidence intervals (CI) were calculated by Joinpoint Regression Analyses.

RESULTS

We found a significant increase of incidence in children aged 5-9 with the APC of 5.7% (95%CI: 2.3-9.1), and in children aged 10-14 with the APC of 2.1% (95%CI: 0.6-3.6). A significant decrease of incidence was determined in adolescents aged 15-19 with the APC -4.9% (95%CI: - 8.9 to - 0.7) and in adults aged 25-29 with the APC -7.3% (95%CI: - 12.5 to - 1.8).

CONCLUSION

The increase of incidence in children aged 0-14 and its decrease after 15 years of age showed that T1DM is predominantly a metabolic disease of children in Serbia. A significant increase in incidence was recorded in two age groups, namely 5-9 and 10-14 years of age. The highest increase was in children aged 5-9 and the highest incidence rate was in children aged 10-14. An insignificant increasing of T2DM incidence was observed in young adults aged 25-29. The increase in incidence rates in children, but not in young adults, suggests that the precipitating factors of children-onset disease may differ from those of adult-onset T1DM.

Enterovirus Neutralizing Antibodies, Monocyte Toll Like Receptors Expression and Interleukin Profiles Are Similar Between Non-affected and Affected Siblings From Long-Term Discordant Type 1 Diabetes Multiplex-Sib Families: The Importance of HLA Background

Enteroviruses are main candidates among environmental agents in the development of type 1 diabetes (T1D). However, the relationship between virus and the immune system response during T1D pathogenesis is heterogeneous. This is an interesting paradigm and the search for answers would help to highlight the role of viral infection in the etiology of T1D. The current data is a cross-sectional study of affected and non-affected siblings from T1D multiplex-sib families to analyze associations among T1D, genetic, islet autoantibodies and markers of innate immunity. We evaluated the prevalence of anti-virus antibodies (Coxsackie B and Echo) and its relationships with human leukocyte antigen (HLA) class II alleles, TLR expression (monocytes), serum cytokine profile and islet β cell autoantibodies in 51 individuals (40 T1D and 11 non-affected siblings) from 20 T1D multiplex-sib families and 54 healthy control subjects. The viral antibody profiles were similar among all groups, except for antibodies against CVB2, which were more prevalent in the non-affected siblings. TLR4 expression was higher in the T1D multiplex-sib family's members than in the control subjects. TLR4 expression showed a positive correlation with CBV2 antibody prevalence (rS: 0.45; P = 0.03), CXCL8 (rS: 0.65, P = 0.002) and TNF-α (rS: 0.5, P = 0.01) serum levels in both groups of T1D multiplex-sib family. Furthermore, within these families, there was a positive correlation between HLA class II alleles associated with high risk for T1D and insulinoma-associated protein 2 autoantibody (IA-2A) positivity (odds ratio: 38.8; P = 0.021). However, the HLA protective haplotypes against T1D prevalence was higher in the non-affected than the affected siblings. This study shows that although the prevalence of viral infection is similar among healthy individuals and members from the T1D multiplex-sib families, the innate immune response is higher in the affected and in the non-affected siblings from these families than in the healthy controls. However, autoimmunity against β-islet cells and an absence of protective HLA alleles were only observed in the T1D multiplex-sib members with clinical disease, supporting the importance of the genetic background in the development of T1D and heterogeneity of the interaction between environmental factors and disease pathogenesis despite the high genetic diversity of the Brazilian population.

Double or hybrid diabetes: A systematic review on disease prevalence, characteristics and risk factors

Diabetes mellitus is a worldwide epidemic affecting the health of millions of people. While type 1 diabetes (T1D) is caused by autoimmune destruction of the insulin-producing beta cells of the pancreas, type 2 diabetes (T2D) results from a combination of insulin resistance and beta cell insulin secretory defect. Clear definition and diagnosis of these two types of diabetes has been increasing more and more difficult, leading to the inclusion of a new category, namely double or hybrid diabetes (DD) that demonstrates symptoms of both T1D and T2D via the accelerator hypothesis. In this review, we discuss the worldwide prevalence of DD, its main physiological characteristics, including beta-cell autoimmunity, insulin resistance, and cardiovascular disease, the main risk factors of developing DD, mainly genetics, obesity and lifestyle choices, as well as potential treatments, such as insulin titration, metformin and behavioural modifications. Increasing awareness of DD among the general population and primary care practitioners is necessary for successfully treating this complex, hybrid disease in the future.

The Risk of Offspring Psychiatric Disorders in the Setting of Maternal Obesity and Diabetes

BACKGROUND

Prenatal exposure to metabolic disturbances is associated with increased risk of offspring neurodevelopmental impairment and autism spectrum disorder, while little is known about the joint effect of maternal obesity and diabetes. With this study, we aim to assess the joint effect of maternal obesity and diabetes on the risk for offspring psychiatric and mild neurodevelopmental disorders.

METHODS

Nationwide registries were used to link data of all live births in Finland between 2004 and 2014 (n = 649 043). Cox proportional hazards modeling adjusting for potential confounders was applied to estimate the effect of maternal obesity, pregestational diabetes mellitus (PGDM), and gestational diabetes mellitus, as well as their joint effects, on the outcomes of offspring psychiatric and mild neurodevelopmental diagnoses and offspring prescription of psychotropic drugs.

RESULTS

Among mothers without diabetes, severely obese mothers had 67% to 88% increased risk of having a child with mild neurodevelopmental disorders (hazard risk ratio [HR] = 1.69; 95% confidence interval [CI] = 1.54-1.86), attention-deficit/hyperactivity disorder or conduct disorder (HR = 1.88; 95% CI = 1.58-2.23), and psychotic, mood, and stress-related disorders (HR = 1.67; 95% CI = 1.31-2.13) compared with mothers with a normal BMI. PGDM implied a further risk increase for all groups of psychiatric diagnoses with onset in childhood or adolescence in mothers with severe obesity. Marked effects were found particularly for autism spectrum disorder (HR = 6.49; 95% CI = 3.08-13.69), attention-deficit/hyperactivity disorder and conduct disorder (HR = 6.03; 95% CI = 3.23-11.24), and mixed disorders of conduct and emotions (HR = 4.29; 95% CI = 2.14-8.60). Gestational diabetes mellitus did not increase the risk highly for these offspring disorders.

CONCLUSIONS

Maternal PGDM combined with severe maternal obesity markedly increases the risk of several children's psychiatric and mild neurodevelopmental disorders.

Emerging Approaches in Surveillance of Type 1 Diabetes

PURPOSE OF REVIEW

Surveillance of type 1 diabetes provides an opportunity to address public health needs, inform etiological research, and plan health care services. We present issues in type 1 diabetes surveillance, review previous and current methods, and present new initiatives.

RECENT FINDINGS

Few diabetes surveillance systems distinguish between type 1 and type 2 diabetes. Most worldwide efforts have focused on registries and ages < 15 years, resulting in limited information among adults. Recently, surveillance includes use of electronic health information and national health surveys. However, distinguishing by diabetes type remains a challenge. Enhancing and improving surveillance of type 1 diabetes across all age groups could include validating questions for use in national health surveys. In addition, validated algorithms for classifying diabetes type in electronic health records could further improve surveillance efforts and close current gaps in our understanding of the epidemiology of type 1 diabetes.

Working people with type 1 diabetes in the Finnish population

Background

The incidence of type 1 diabetes is increasing worldwide. Since so little is known about work life of individuals with type 1 diabetes, we examined incidence and prevalence trends of type 1 diabetes among working-aged Finns. We also investigated the employment rate and how workers with type 1 diabetes perceive their health and work ability, and their intended retirement age.

Methods

We analyzed changes in the incidence, prevalence, and employment rate using nationwide multi-register-based FinDM data, and estimated a Self-Rated Health, Work Ability Score, and inquired about retirement intentions of 767 working individuals with type 1 diabetes in a cross-sectional survey. All estimates were compared to the corresponding data of the Finnish general population.

Results

The average annual age-standardized incidence rate of type 1 diabetes among men aged 18–39 was 29 per 100,000/year; the incidence rate has increased by 33% from 1992 to 2007. Among women, the incidence remained at 16 per 100,000/year. Among working-aged (18–64) people, the age-standardized prevalence of type 1 diabetes increased by 39% among women and 33% among men. Two out of every three working aged individuals with type 1 diabetes were in the labor force; this is about 10% lower than in the Finnish population. The average age-standardized employment rate among those individuals with type 1 diabetes belonging to the labor force was 82%, compared to 84% in the general population. Working individuals with type 1 diabetes rated their health and work ability as being slightly lower than the general working population, but nonetheless, there were no significant differences in retirement intentions.

Conclusions

Between 1992 and 2007, the number of working-aged people and workers with type 1 diabetes increased by 35%. Most workers with type 1 diabetes manage as well at work as the general population. Special attention should be paid to workers with type 1 diabetes when they are diagnosed and/or report moderate or poor work ability.

Electronic supplementary material

The online version of this article (10.1186/s12889-017-4723-8) contains supplementary material, which is available to authorized users.

Multiple complications among people with diabetes from Finland: an 18-year follow-up in 1994-2011

OBJECTIVE

In this study, we examined trends in severe diabetes-related complications (acute myocardial infarction, stroke, lower extremity amputation, and end-stage renal disease) and prevalence of multiple complications in a total population with diabetes in Finland during an 18-year period.

RESEARCH DESIGN AND METHODS

The total population with diabetes aged 30 years or older in 1994-2011 was obtained from several Finnish health registers. Only the first episode of each end point was included in the analysis. We examined trends in the prevalence of these end points using age-standardization and changes in these end points were analyzed using repeated-measures Poisson regression models.

RESULTS

The prevalence of single comorbidities decreased during the study period, especially for acute myocardial infarction and stroke. The age-adjusted and diabetes duration-adjusted risk of having one of these end points decreased throughout the study period among persons with type 2 diabetes. Among women, the risk ratio was 0.71 (0.63 to 0.79) in 2006-2011 compared to 1994-1999, and among men, the figure was 0.72 (0.66 to 0.78). In type 1 diabetes, the risk of multiple serious complications increased. We further found increased mortality risk among persons with any of these complications irrespective of diabetes type.

CONCLUSIONS

Our results concerning the development of risk of complications suggest improvements in the management of diabetes. More attention needs to be paid to the prevention of complications among older persons and those with longer history of diabetes to prevent clustering of complications and to prevent the diabetes epidemic in the population to reduce the public health burden of diabetes.

Gender difference in type 2 diabetes and the role of body iron stores

Background Studies of gender difference in type 2 diabetes have been inconclusive. We investigated gender difference in type 2 diabetes and the contribution of body iron, as assessed by serum ferritin to this difference. Methods We performed cross-sectional ( n = 1707) and prospective ( n = 1506) analyses in males and females aged 53-73 years in 1998-2001. Type 2 diabetes diagnosis was determined by questionnaire, blood glucose measurements and record linkage to type 2 diabetes registers. Gender difference in type 2 diabetes and serum ferritin contribution to the difference was examined in multivariable logistic and Cox regression models. Gender difference in fasting plasma glucose and insulin and homeostasis model assessment of insulin resistance was examined in linear regression analysis. Results In the cross-sectional analysis, a total of 201 type 2 diabetes cases were observed (males = 111 [55.2%] vs. female = 90 [44.8%], P = 0.032), and in adjusted models, males had higher odds of type 2 diabetes (OR = 1.61, 95% CI 1.10 to 2.34); higher fasting plasma glucose (β = 0.28, 95% CI 0.15 to 0.41), fasting plasma insulin (β = 0.73, 95% CI 0.26 to 1.19) and homeostasis model assessment of insulin resistance (β = 0.11, 95% CI 0.04 to 0.17). In the prospective analysis, males had increased risk of type 2 diabetes (HR = 1.46, 95% CI 1.03 to 2.07). With serum ferritin introduction (100  µg/L, log-transformed) into the models, the type 2 diabetes prevalence (OR = 1.35, 95% CI 0.91 to 1.99) and incidence (HR = 1.38, 95% CI 0.96 to 1.97) were appreciably attenuated. Conclusions These data suggest a gender difference in type 2 diabetes, with a higher prevalence and increased type 2 diabetes risk in males. Body iron explains about two-fifths and one-fifth of the gender difference in type 2 diabetes prevalence and incidence, respectively.

Regional trends in avoidable hospitalisations due to complications among population with diabetes in Finland in 1996-2011: a register-based cohort study

OBJECTIVES

Diabetes requires continuous medical care including prevention of acute complications and risk reduction for long-term complications. Diabetic complications impose a substantial burden on public health and care delivery. We examined trends in regional differences in hospitalisations due to diabetes-related complications among the total diabetes population in Finland.

RESEARCH DESIGN

A longitudinal register-based cohort study 1996-2011 among a total population with diabetes in Finland.

PARTICIPANTS

All persons with diabetes identified from several administrative registers in Finland in 1964-2011 and alive on 1 January 1996.

OUTCOME MEASURES

We examined hospitalisations due to diabetes-related short-term and long-term complications, uncomplicated diabetes, myocardial infarction, stroke, lower extremity amputation and end-stage renal disease (ESRD). We calculated annual age-adjusted rates per 10 000 person years and the systematic component of variation. Multilevel models were used for studying time trends in regional variation.

RESULTS

There was a steep decline in complication-related hospitalisation rates during the study period. The decline was relatively small in ESRD (30%), whereas rates of hospitalisations for short-term and long-term complications as well as uncomplicated diabetes diminished by about 80%. The overall correlation between hospital district intercepts and slopes in time was -0.72 (p<0.001) among men and -0.99 (p<0.001) among women indicating diminishing variation. Diminishing variation was found in each of the complications studied. The variation was mainly distributed at the health centre level.

CONCLUSIONS

Our study suggests that the prevention of complications among persons with diabetes has improved in Finland between 1996 and 2011. The results further suggest that the prevention of complications has become more uniform throughout the country.

Retinopathy is associated with impaired myocardial function assessed by advanced echocardiography in type 1 diabetes patients - The Thousand & 1 Study

AIMS

Retinopathy and heart disease in Type 1 Diabetes Mellitus (Type 1 DM) may be associated; however previous results have been conflicting. Tissue Doppler Imaging (TDI) and speckle-tracking echocardiography (STE) quantify myocardial function not assessable by conventional echocardiography. We investigated the association between severity of retinopathy and early myocardial dysfunction using conventional echocardiography, TDI and STE in Type 1 DM patients.

METHODS

Type 1 Diabetes Mellitus patients without known heart disease were included from the Steno Diabetes Center. The cross sectional association between retinopathy and myocardial function was analyzed in uni-and multivariable models. Retinopathy was categorized as nil-, simplex- or proliferative retinopathy.

RESULTS

A total of 1090 Type 1 Diabetes Mellitus patients were included, mean age was 49.6years and 53% were males. Left ventricular ejection fraction did not differ between groups of retinopathy. Global longitudinal strain (GLS) by STE decreased significantly with increasing degrees of retinopathy (nil; -18.6%, simplex; -18.2% (p=0.024), proliferative; -17.7% (p<0.001)), however differences attenuated in multivariable models (p⩾0.05). In univariable models, myocardial tissue velocities differed in relation to retinopathy: s' (nil; 6.9, simplex; 6.5, proliferative; 5.9 (p=0.001), e' (nil; 10.4, simplex; 9.2, proliferative; 7.9, p<0.001), a' (nil; 6.1, simplex; 6.7, proliferative; 7.0, p<0.001) and E/e' (nil; 6.7, simplex; 7.5, proliferative; 9.5, p<0.001). In multivariable models, differences persisted between nil and proliferative retinopathy for s', e' and E/e'.

CONCLUSION

Proliferative retinopathy is independently associated with decreased myocardial function assessed by Tissue Doppler Imaging in patients with Type 1 Diabetes Mellitus without history of heart disease.

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.

Improving visual prognosis of the diabetic patients during the past 30 years based on the data of the Finnish Register of Visual Impairment

PURPOSE

To evaluate changes in visual impairment (VI) due to diabetic retinopathy (DR) recorded in the Finnish Register of Visual Impairment (RVI) during the past 30 years.

METHODS

Data from the visually impaired diabetic persons included in the RVI were analysed using three 10-year cohorts (1982-90, 1991-2000, 2001-10). Information on the age at the time of the first VI registration, severity of VI determined according to the World Health Organisation (WHO) definition, and the age at death was collected. VI due to proliferative (PDR) and non-proliferative (NPDR) DR were analysed separately.

RESULTS

Data of 4080 patients whose primary cause for VI was DR were analysed. The median age at the time of notification of VI for the three cohorts was 39, 62 and 59 years in the PDR group and 71, 73 and 73 in the NPDR group, respectively. The proportion of blind persons was 42%, 22% and 15% in the PDR group and 10%, 9% and 4% in the NPDR group, respectively. The median age at death in the three cohorts was 54, 73 and 72 years in PDR group and 76, 79 and 80 years in the NPDR group, respectively. The standardized mortality ratio (SMR) compared with the general population was 8.3, 2.9 and 1.4 in persons with PDR and 3.4, 2.0 and 1.2 in those with NPDR, respectively.

CONCLUSIONS

A significant change in the profile of the VI in the PDR group has taken place in Finland. It was characterized by increased age at the time of VI notification, decreased severity of VI and higher age at death. Most evidently these improvements took place in the 1990s. The profile of VI in the NPDR group has changed only modestly. Compared with the general population, SMRs improved both in NPDR and PDR groups continuously.

Double-diabetes in a real-world sample of 2711 individuals: associated with insulin treatment or part of the heterogeneity of type 1 diabetes?

BACKGROUND

Double diabetes (DD) describes both individuals with obesity upon diagnosis of type 1 diabetes and those who have gained weight during follow-up, although cardiovascular risk factors (CVRF) are not well understood in this group. We aim to evaluate the frequency of DD in a real-world type 1 diabetes sample and the interaction of insulin treatment with CVRF.

METHODS

Multicentre cross-sectional study of 2711 individuals with clinical diagnosis of type 1 diabetes from secondary diabetes centres in 20 Brazilian cities.

RESULTS

Patients with diabetes duration <5 and ≥5 years had similar frequency of overweight (20.4 vs. 25 %) and obesity, (9.8 vs. 6.1 %), p 0.28 for trend. Insulin dose (U/kg/day) was lower in obese individuals compared to normal BMI, with mean (95 % CI) 0.72 (0.62-0.83) vs. 0.88 (0.84-0.92) U/kg/day for diabetes duration <5 years and 0.84 (0.77-0.92) vs. 0.99 (0.97-1.01) U/kg/day for duration ≥5 years. Obese individuals had lower HDL (47.5 vs. 54.4 mg/dL) and higher non-HDL-cholesterol (134.5 vs. 115.2 mg/dL) than lean ones only among those with more than 5 years of diabetes.

CONCLUSIONS

Lower insulin doses in obese individuals point to a role of clinical heterogeneity in insulin deficiency rather than normal progression of type 1 diabetes. Early obesity in type 1 diabetes is associated to lower HDL-cholesterol and higher number of CVRF. These data suggest a broad landscape of pathophysiological phenomena in double diabetes, rather than simple progression of a homogeneous clinical entity.

Secular trends and educational differences in the incidence of type 2 diabetes in Finland, 1972-2007

Type 2 diabetes prevalence is rising globally, and varies by socio-economic position. Amongst other factors, rising prevalence may reflect increasing incidence. Worldwide, few studies have examined population-level longitudinal trends in incident type 2 diabetes, and reports on secular trends in diabetes incidence by socio-economic measures such as educational attainment are lacking. Finland has a long-standing, comprehensive disease surveillance infrastructure. Using data collected over four decades from serial FINRISK surveys, the National Drug Reimbursement Register and the National Causes of Death Register, we examined secular trends in type 2 diabetes incidence in Finland from the 1970s to 2007. The diabetes status of 38,689 FINRISK participants aged 30-59 years at baseline assessment and without diagnosed diabetes at the time was followed for 10 years. Among men, incidence of diagnosed, pharmacologically managed type 2 diabetes increased over time. Compared with men surveyed in the 1970s, diabetes incidence was higher among men in the 1980s (adjusted HR 1.44, 95% CI 1.13-1.84) and 1990s (adjusted HR 1.72, 1.32-2.24). Body mass index explained some, but not all of this variation. Increases occurred predominantly among men with low (adjusted HR 1980s: 2.07, 95% CI 1.28-3.35; adjusted HR 1990s: 2.12, 95% CI 1.28-3.53) and middle (adjusted HR 1980s: 1.30, 95% CI 0.85-1.99; adjusted HR 1990s: 1.65, 95% CI 1.05-2.60) educational attainment. No secular changes were apparent among women. This rising diabetes incidence among men over recent decades has occurred despite Finland's sustained health promotion efforts. Renewed public health campaigns are urgently required. In addition to population-level initiatives, lower educational strata should be specifically targeted.

Medical and non-medical complications among children and adolescents with excessive body weight

BACKGROUND

The burden of disease from childhood obesity is considerable worldwide, as it is associated with several co-morbidities, such as dyslipidemia, hypertension, type 2 diabetes (T2DM), orthopedic and psychosocial problems. We aimed at determining the prevalence of these complications in a population of children and adolescents with body weight excess.

METHODS

This is a cohort study including 774 new patients (1.7 - 17.9 yrs, mean 11.1 ± 3.0) attending a pediatric obesity care center. We assessed personal and family medical histories, physical examination, systemic blood pressure, biochemical screening tests.

RESULTS

We found that the great majority of the children suffered from at least one medical complication. Orthopedic pathologies were the most frequent (54%), followed by metabolic (42%) and cardiovascular disturbances (31%). However, non-medical conditions related to well-being, such as bullying, psychological complaints, shortness of breath or abnormal sleeping patterns, were present in the vast majority of the children (79.4%). Family history of dyslipidemia tends to correlate with the child's lipids disturbance (p = .053), and ischemic events or T2DM were correlated with cardiovascular risk factors present in the child (p = .046; p = .038, respectively).

CONCLUSIONS

The vast majority of obese children suffer from medical and non-medical co-morbidities which must be actively screened. A positive family history for cardiovascular diseases or T2DM should be warning signs to perform further complementary tests. Furthermore, well-being related-complaints should not be underestimated as they were extremely frequent.

The increased risk for autoimmune diseases in patients with eating disorders

Objective

Research suggests autoimmune processes to be involved in psychiatric disorders. We aimed to address the prevalence and incidence of autoimmune diseases in a large Finnish patient cohort with anorexia nervosa, bulimia nervosa, and binge eating disorder.

Methods

Patients (N = 2342) treated at the Eating Disorder Unit of Helsinki University Central Hospital between 1995 and 2010 were compared with general population controls (N = 9368) matched for age, sex, and place of residence. Data of 30 autoimmune diseases from the Hospital Discharge Register from 1969 to 2010 were analyzed using conditional and Poisson regression models.

Results

Of patients, 8.9% vs. 5.4% of control individuals had been diagnosed with one or more autoimmune disease (OR 1.7, 95% CI 1.5–2.0, P<0.001). The increase in endocrinological diseases (OR 2.4, 95% CI 1.8–3.2, P<0.001) was explained by type 1 diabetes, whereas Crohn's disease contributed most to the risk of gastroenterological diseases (OR 1.8, 95% CI 1.4–2.5, P<0.001). Higher prevalence of autoimmune diseases among patients with eating disorders was not exclusively due to endocrinological and gastroenterological diseases; when the two categories were excluded, the increase in prevalence was seen in the patients both before the onset of the eating disorder treatment (OR 1.5, 95% CI 1.1–2.1, P = 0.02) and at the end of the follow-up (OR 1.4, 95% CI 1.1–1.8, P = 0.01).

Conclusions

We observed an association between eating disorders and several autoimmune diseases with different genetic backgrounds. Our findings support the link between immune-mediated mechanisms and development of eating disorders. Future studies are needed to further explore the risk of autoimmune diseases and immunological mechanisms in individuals with eating disorders and their family members.

Cardiovascular risk factors in 2011 and secular trends since 2007: the Cardiovascular Risk in Young Finns Study

AIMS

Cardiovascular risk factor levels in 2011 and 4-year changes between 2007 and 2011 were examined using data collected in follow-ups of the Cardiovascular Risk in Young Finns Study.

METHODS

The study population comprised 2063 Finnish adults aged 34-49 years (45% male). Lipid and blood pressure levels, glucose and anthropometry were measured and life style risk factors examined with questionnaires.

RESULTS

Mean total cholesterol level in 2011 was 5.19 mmol/l, low density lipoprotein (LDL)-cholesterol 3.27 mmol/l, high density lipoprotein (HDL)-cholesterol 1.33 mmol/l, and triglycerides 1.34 mmol/l. Using American Diabetes Association criteria, Type 2 diabetes (T2D) was observed in 4.1% and prediabetes (fasting glucose 5.6-6.9 mmol/l or glycated hemoglobin 5.7-6.4%) diagnosed for 33.8% of the participants. Significant changes (P < 0.05) between 2007 and 2011 included an increase in waist circumference (3.3%) in women. In both sexes, systolic (-3.0% in women, -4.0% in men) and diastolic (-3.0% in women, -3.3% in men) blood pressure and triglycerides (-3.4% in women, -6.5% in men) decreased during follow-up.

CONCLUSIONS

Previously observed favorable trends in ldl-cholesterol levels have leveled off among a sample of young and middle-aged adults in finland triglyceride and blood pressure levels have decreased over one-third of the study population had prediabetes and may be at increased risk for T2D:

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.

Treatment of depression in diagnosed diabetes: common cause or detection bias?

BACKGROUND

This study examined two competing hypotheses concerning the association between diabetes and treatment for depression: (1) the detection/ascertainment bias hypothesis suggesting that those with diabetes are more likely to be diagnosed with and treated for depression because of increased medical attention and (2) a hypothesis assuming that diabetes and depression share common underlying pathophysiological pathways.

METHOD

The study population included all persons aged 35-65 years in Finland with any record of type 2 diabetes in the national health and population registers from 1999 to 2002 and for whom register-based data on depression treatment (antidepressant medication use and hospitalizations for depression) were available at least 2 years before and after the diagnosis of diabetes (n = 18,217). Sociodemographic data were individually linked to the study population. Associations between diabetes diagnosis and time and indicators of depression care were assessed with population-averaged multilevel logistic models.

RESULTS

Within the year following diagnosis diabetes, there was a 5% increase in antidepressant medication use but not in hospitalization for depression. The longitudinal change in antidepressant use over time was less steep after the diabetes diagnosis, and hospitalization risk decreased after the diagnosis. These associations between diabetes diagnosis and depression treatment were not modified by the participant's socio-economic position (SEP).

CONCLUSIONS

These findings support the common cause hypothesis that treatment for diabetes is beneficial to the prevention of depression rather than the detection/ascertainment hypothesis that individuals with diabetes have higher rates of depression because they receive more medical attention in general.

Diabetes in Europe: an update

Diabetes is among the leading causes of death in the IDF Europe Region (EUR), continues to increase in prevalence with diabetic macro- and microvascular complications resulting in increased disability and enormous healthcare costs. In 2013, the number of people with diabetes is estimated to be 56 million in EUR with an overall estimated prevalence of 8.5%. However, estimates of diabetes prevalence in 2013 vary widely in the 56 diverse countries in EUR from 2.4% in Moldova to 14.9% in Turkey. Trends in diabetes prevalence also vary between countries with stable prevalence since 2002 for many countries but a doubling of diabetes prevalence in Turkey. For 2035, a further increase of nearly 10 million people with diabetes is projected for the EUR. Prevalence of type 1 has also increased over the past 20 years in EUR and there was estimated to be 129,350 cases in children aged 0-14 years in 2013. Registries provide valid information on incidence of type 1 diabetes with more complete data available for children than for adults. There are large differences in distribution of risk factors for diabetes at the population level in EUR. Modifiable risk factors such as obesity, physical inactivity, smoking behaviour (including secondhand smoking), environmental pollutants, psychosocial factors and socioeconomic deprivation could be tackled to reduce the incidence of type 2 diabetes in Europe. In addition, diabetes management is a major challenge to health services in the European countries. Improved networking practices of health professionals and other stakeholders in combination with empowerment of people with diabetes and continuous quality monitoring need to be further developed in Europe.

Impact of sex and age at onset of diabetes on mortality from ischemic heart disease in patients with type 1 diabetes

OBJECTIVE To study whether ischemic heart disease (IHD) mortality among patients with type 1 diabetes (T1D) depends on the age at onset of diabetes and whether this effect is sex specific. RESEARCH DESIGN AND METHODS The study examined long-term IHD-specific mortality in a Finnish population-based cohort of patients with early-onset (0-14 years) and late-onset (15-29 years) T1D (n = 17,306). RESULTS During 433,782 person-years of follow-up, 478 deaths from IHD were observed. Within the early-onset cohort, the average crude mortality rate in women was 33.3% lower than in men, whereas in the late-onset cohort, mortality was only one-half that in men. In contrast, the standardized mortality ratio (SMR) was higher in women than in men (21.6 [95% CI 17.2-27.0] vs. 5.8 [5.1-6.6]). The difference in SMR between sexes was more striking in the early-onset cohort (women 52.8 [36.3-74.5], men 12.1 [9.2-15.8]). The SMR was also greater in women in the late-onset cohort (15.8 [11.8-20.7]) compared with men (5.0 [4.3-5.8]). The relative risk of dying from IHD was greatest in women aged <40 years and 40-60 years in the early- and late-onset cohorts, respectively. CONCLUSIONS The risk of mortality from IHD is exceptionally high in women with early-onset T1D compared with women in the background population. These observations underscore the importance of identifying risk factors early in women and delivering more-aggressive treatment after diagnosis.

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.

Secular changes in the age-specific prevalence of diabetes among U.S. adults: 1988-2010

OBJECTIVE

To examine the age-specific changes of prevalence of diabetes among U.S. adults during the past 2 decades.

RESEARCH DESIGN AND METHODS

This study included 22,586 adults sampled in three periods of the National Health and Nutrition Examination Survey (1988-1994, 1999-2004, and 2005-2010). Diabetes was defined as having self-reported diagnosed diabetes or having a fasting plasma glucose level ≥ 126 mg/dL or HbA1c ≥ 6.5% (48 mmol/mol).

RESULTS

The number of adults with diabetes increased by 75% from 1988-1994 to 2005-2010. After adjusting for sex, race/ethnicity, and education level, the prevalence of diabetes increased over the two decades across all age-groups. Younger adults (20-34 years of age) had the lowest absolute increase in diabetes prevalence of 1.0%, followed by middle-aged adults (35-64) at 2.7% and older adults (≥ 65) at 10.0% (all P < 0.001). Comparing 2005-2010 with 1988-1994, the adjusted prevalence ratios (PRs) by age-group were 2.3, 1.3, and 1.5 for younger, middle-aged, and older adults, respectively (all P < 0.05). After additional adjustment for body mass index (BMI), waist-to-height ratio (WHtR), or waist circumference (WC), the adjusted PR remained statistically significant only for adults ≥ 65 years of age.

CONCLUSIONS

During the past two decades, the prevalence of diabetes increased across all age-groups, but adults ≥ 65 years of age experienced the largest increase in absolute change. Obesity, as measured by BMI, WHtR, or WC, was strongly associated with the increase in diabetes prevalence, especially in adults <65.

Increased cancer mortality in diabetic people treated with insulin: a register-based follow-up study

Background

The national 10-year Development Programme for the Prevention and Care of Diabetes (DEHKO) was launched in Finland in 2000. The program focused on improving early diagnosis of type 2 diabetes and preventing diabetes-related complications. The FinDM database was established for epidemiological monitoring of diabetes and its complications. This study monitors mortality trends among people with diabetes during the DEHKO programme.

Methods

A database obtained from a compilation of several administrative national health registers was used to study mortality in people with diabetes in 1998–2007. Relative excess mortality between people with and without diabetes was analyzed using Poisson regression models.

Results

The number of diabetic people in Finland increased by 66% from 1997 reaching 284 832 in 2007. Like among non-diabetic people, all-cause mortality decreased in people with diabetes. Overall excess mortality remained high in people with diabetes; in 2003–2007 RRs in the non-insulin treated was 1.82 for men and 1.95 for women and in the insulin treated 3.45 and 4.29, and excess coronary heart disease mortality in the insulin treated: RR was 4.71 in men and 7.80 in women. A striking result was mortality from neoplasms; an increase in mortality emerged in almost every age group of insulin treated women.

Conclusion

Compared to non-diabetic people our monitoring showed declining excess mortality in non-insulin treated diabetic people mainly due to a decrease in mortality from cardiovascular diseases. For insulin treated, relative overall excess mortality remained unchanged and mortality from neoplasms increased among women.

Is the risk and nature of CVD the same in type 1 and type 2 diabetes?

The incidence of both type 1 and type 2 diabetes is increasing globally, most likely explained by environmental changes, such as changing exposures to foods, viruses, and toxins, and by increasing obesity. While cardiovascular disease (CVD) mortality has been declining recently, this global epidemic of diabetes threatens to stall this trend. CVD is the leading cause of death in both type 1 and type 2 diabetes, with at least a two- to fourfold increased risk in patients with diabetes. In this review, the risk factors for CVD are discussed in the context of type 1 and type 2 diabetes. While traditional risk factors such as dyslipidemia, hypertension, and obesity are greater in type 2 patients than in type 1 diabetes, they explain only about half of the increased CVD risk. The role for diabetes-specific risk factors, including hyperglycemia and kidney complications, is discussed in the context of new study findings.

Projections of type 1 and type 2 diabetes burden in the U.S. population aged <20 years through 2050: dynamic modeling of incidence, mortality, and population growth

OBJECTIVE

To forecast the number of U.S. individuals aged <20 years with type 1 diabetes mellitus (T1DM) or type 2 diabetes mellitus (T2DM) through 2050, accounting for changing demography and diabetes incidence.

RESEARCH DESIGN AND METHODS

We used Markov modeling framework to generate yearly forecasts of the number of individuals in each of three states (diabetes, no diabetes, and death). We used 2001 prevalence and 2002 incidence of T1DM and T2DM from the SEARCH for Diabetes in Youth study and U.S. Census Bureau population demographic projections. Two scenarios were considered for T1DM and T2DM incidence: 1) constant incidence over time; 2) for T1DM yearly percentage increases of 3.5, 2.2, 1.8, and 2.1% by age-groups 0-4 years, 5-9 years, 10-14 years, and 15-19 years, respectively, and for T2DM a yearly 2.3% increase across all ages.

RESULTS

Under scenario 1, the projected number of youth with T1DM rises from 166,018 to 203,382 and with T2DM from 20,203 to 30,111, respectively, in 2010 and 2050. Under scenario 2, the number of youth with T1DM nearly triples from 179,388 in 2010 to 587,488 in 2050 (prevalence 2.13/1,000 and 5.20/1,000 [+144% increase]), with the greatest increase in youth of minority racial/ethnic groups. The number of youth with T2DM almost quadruples from 22,820 in 2010 to 84,131 in 2050; prevalence increases from 0.27/1,000 to 0.75/1,000 (+178% increase).

CONCLUSIONS

A linear increase in diabetes incidence could result in a substantial increase in the number of youth with T1DM and T2DM over the next 40 years, especially those of minority race/ethnicity.

The regional association of rising type 2 diabetes incidence with magnesium in drinking water among young adults

The incidence of type 2 diabetes is increasing among Finnish young adults. A slightly increased risk in men was found in the north-east and western part of the country. The higher risk areas in women were found in the western coastal area and in eastern Finland. The present register-based study aimed to evaluate the regional association of the incidence of type 2 diabetes among young adults with the concentration of magnesium in local ground water. The association was evaluated using Bayesian modeling of geo-referenced data aggregated into a regular 10 km × 10 km grid cells. No marked association was found, although suggestive findings were detected for magnesium in well water and diabetes in young adult women. The results of this register-based study did not completely rule out the association of well water magnesium with the geographical variation of type 2 diabetes. The incidence of type 2 diabetes was much higher among individuals aged 40 or over. These suggestive findings indicate that the association between magnesium and type 2 diabetes would also be worth examining among individuals over 40 years of age.

Time trends in mortality in patients with type 1 diabetes: nationwide population based cohort study

OBJECTIVE

To examine short and long term time trends in mortality among patients with early onset (age 0-14 years) and late onset (15-29 years) type 1 diabetes and causes of deaths over time.

DESIGN

Population based nationwide cohort study.

SETTING

Finland.

PARTICIPANTS

All Finnish patients diagnosed as having type 1 diabetes below age 30 years between 1970 and 1999 (n = 17,306).

MAIN OUTCOME MEASURES

Crude mortality, standardised mortality ratios, time trends, and cumulative mortality.

RESULTS

A total of 1338 deaths occurred during 370,733 person years of follow-up, giving an all cause mortality rate of 361/100,000 person years. The standardised mortality ratio was 3.6 in the early onset cohort and 2.8 in the late onset cohort. Women had higher standardised mortality ratios than did men in both cohorts (5.5 v 3.0 in the early onset cohort; 3.6 v 2.6 in the late onset cohort). The standardised mortality ratio at 20 years' duration of diabetes in the early onset cohort decreased from 3.5 in the patients diagnosed in 1970-4 to 1.9 in those diagnosed in 1985-9. In contrast, the standardised mortality ratio in the late onset cohort increased from 1.4 in those diagnosed in 1970-4 to 2.9 in those diagnosed in 1985-9. Mortality due to chronic complications of diabetes decreased with time in the early onset cohort but not in the late onset cohort. Mortality due to alcohol related and drug related causes increased in the late onset cohort and accounted for 39% of the deaths during the first 20 years of diabetes. Accordingly, mortality due to acute diabetic complications increased significantly in the late onset cohort.

CONCLUSION

Survival of people with early onset type 1 diabetes has improved over time, whereas survival of people with late onset type 1 diabetes has deteriorated since the 1980s. Alcohol has become an important cause of death in patients with type 1 diabetes, and the proportion of deaths caused by acute complications of diabetes has increased in patients with late onset type 1 diabetes.

Survival of patients with type 1 diabetes receiving renal replacement therapy in 1980-2007

OBJECTIVE

Risks of end-stage renal disease and premature death in patients with type 1 diabetes have declined over the past decades. Data on the survival of patients receiving renal replacement therapy (RRT) are, however, limited. We investigated whether survival of patients with type 1 diabetes receiving RRT has improved over time and whether improvement can be attributable to progress in dialysis treatment or diabetes care.

RESEARCH DESIGN AND METHODS

An incident cohort of all patients with type 1 diabetes (n = 1,604) starting chronic RRT in Finland between 1980 and 2005 were followed until death or end of follow-up on 31 December 2007. The control group (n = 1,556) consisted of patients with glomerulonephritis who started RRT. All patients were identified from the Finnish Registry for Kidney Diseases.

RESULTS

Median survival time of patients with type 1 diabetes increased progressively from 3.60 years during 1980-1984 to >8 years in 2000-2005. In 2000-2005, the unadjusted relative risk of death was 0.55 compared with 1980-1984. After adjustment for the most important variables, the corresponding relative risk of death was only 0.23. For patients with glomerulonephritis, the adjusted relative risk decreased to a lesser extent to 0.30 (P = 0.007).

CONCLUSIONS

Survival of patients with type 1 diabetes and end-stage renal disease has improved since the 1980s despite a conspicuous increase in the age of patients who start RRT, suggesting not only true progress in dialysis therapy and overall treatment of patients with end-stage renal disease but possibly also improved management of diabetes.

Age at onset of type 1 diabetes in parents and recurrence risk in offspring

OBJECTIVE

Our aim was to study the recurrence risk of type 1 diabetes in the offspring of parents with adult-onset (15-39 years) type 1 diabetes and to evaluate the transmission of diabetes within a continuum of parental age at onset of diabetes from childhood to adulthood.

RESEARCH DESIGN AND METHODS

Diabetes status of all offspring (n = 9,636) in two Finnish cohorts of parents with type 1 diabetes was defined until the end of year 2007. Cumulative incidences of type 1 diabetes among the offspring were estimated, and several factors contributing to the risk were assessed.

RESULTS

During 137,455 person-years, a total of 413 offspring were diagnosed with type 1 diabetes. The cumulative incidence by 20 years was 4.0% (95% CI 3.1-4.8) for the offspring of parents with adult-onset diabetes. The risk was equal according to the sex of the parents. The cumulative incidence decreased in parallel with the increase in age at onset of diabetes in the fathers. In the offspring of diabetic mothers, the risk was equal regardless of the age at onset of diabetes. However, the reduced risk in the maternal offspring was most pronounced in the daughters of the mothers with a diagnosis age <10 years.

CONCLUSIONS

Type 1 diabetes transmission ratio distortion is strongly related to the sex and age at onset of diabetes in the diabetic parents.

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.

The incidence of type 1 diabetes is increasing in both children and young adults in Northern Italy: 1984-2004 temporal trends

AIMS/HYPOTHESIS

A shift towards younger age at onset of diabetes in susceptible people has been suggested as a possible explanation for the increasing temporal trend in incidence of type 1 diabetes. We aimed to test this hypothesis by assessing trends in incidence rates in the period 1984-2004 in children and young adults in Northern Italy.

METHODS

The study bases were: (1) children resident in the Province of Turin in the period 1984-2004 and in the remaining areas of the Piedmont Region in the period 1990-2004; and (2) young adults (15-29 years) resident in the Province of Turin in the period 1984-2003. Temporal trends in rates were analysed using Poisson regression models.

RESULTS

A total of 1,773 incident cases were identified. Overall incidence rates/100,000 person-years in the age groups 0-14 and 15-29 years were 11.3 (95% CI 10.7-12.0) and 7.1 (95% CI 6.6-7.7), respectively, with sex differences among young adults only (incidence rate ratio [IRR] in males vs females 1.41 [95% CI 1.20-1.64]). Average annual increases in incidence rates were similar in children and young adults at 3.3% (95% CI 2.5-4.1). Compared with the period 1984-89, in 2000-2004 a 60% higher risk was found in both age 0-14 years (IRR 1.60, 95% CI 1.31-1.95) and 15-29 years (IRR 1.57, 95% CI 1.26-1.96) groups. The Poisson modelling showed no interaction between calendar period and age at onset.

CONCLUSIONS/INTERPRETATION

Incidence of type 1 diabetes in Northern Italy is increasing over time in both children and young adults, not supporting the hypothesis of a shift towards younger age as the main explanation for the increasing temporal trend in children.

Prevalence of diagnosed and undiagnosed diabetes mellitus and impaired fasting glucose in Sardinia

We aimed at updating the prevalence of impaired fasting glucose (IFG) and of undiagnosed (UD) and diagnosed diabetes (DD) among the Sardinian population. The survey was carried out from 2002 to 2005 on 4.737 subjects aged 20-80+ years. IFG was diagnosed when blood glucose was 110-125 mg/dl; UD when it was >or=126 mg/dl in the absence of personal history of diabetes; DD when personal history was positive, irrespective of blood glucose value. Prevalence rates (%) were adjusted for age by direct method to the Italian 2001 population. IFG was diagnosed in 11% of the sample (9.88% in females and 12.24% in males); UD was found in 5.65% (5.20 and 6.15%, females and males, respectively), DD in 8.72% (6.74 and 10.05%); and total diabetes (TD), i.e. the sum of UD + DD, was 14.37% (12.93 and 15.07%, females and males, respectively). In Sardinia, in about 5 years there was an increase of IFG (+61.8%), UD (+56.9%), DD (+55.7%), and TD (+57.9%). Thus Sardinia participates in the worldwide increase in prevalence of diabetes and its microvascular, macrovascular, and socioeconomic consequences.

Childhood BMI trajectories and the risk of developing young adult-onset diabetes

AIMS/HYPOTHESIS

The aim of this study was to examine the effects of childhood BMI growth dynamics on the risk of developing young adult-onset type 1 and type 2 diabetes.

METHODS

Finnish national healthcare registers were used to identify individuals with diabetes diagnosed between 1992 and 1996 at 15-39 years of age. Non-diabetic control participants were chosen from the National Population Registry. Anthropometric measurements were obtained from the original child welfare clinic records. Only the case-control pairs with sufficient growth data recorded were included in the analyses (218/1,388 for type 1 diabetes [16%] and 64/1,121 for type 2 diabetes [6%]). Two developmental stages in BMI growth (the points of infancy maximum BMI and the BMI rebound) were examined, and conditional logistic regression was applied to the variables of interest.

RESULTS

The risk for type 1 diabetes increased 1.19-fold per 1 kg/m(2) rise in the infancy maximum BMI (p = 0.02). In addition, there was a 1.77-fold increase in the risk for type 2 diabetes per 1 kg/m(2) rise in the level of BMI at the BMI rebound (p = 0.04). Higher values of BMI at these points corresponded to a larger BMI gain from birth to that developmental stage. Age at the infancy maximum BMI or age at the BMI rebound did not affect the risk for either type of diabetes.

CONCLUSIONS/INTERPRETATION

The BMI gain in infancy among individuals who subsequently developed young adult-onset type 1 diabetes was faster than that of those who remained healthy. The excess BMI gain in individuals who developed young adult-onset type 2 diabetes could already be seen during early childhood.

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.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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