Incidence of type 1 (insulin-dependent) diabetes mellitus in Catalonia, Spain. The Catalan Epidemiology Diabetes Study Group

Diabetic Ketoacidosis in Northern Jordan: Seasonal Morbidity and Characteristics of Patients

Purpose

This study aimed to characterize adult patients admitted with diabetic ketoacidosis (DKA) in northern Jordan.

Methods

The study examined medical records of patients diagnosed with DKA from January 2015 to April 2018. Variables analyzed included diabetes type, precipitating illness, admission month, hospital length of stay, and biochemical markers.

Results

Out of 232 admissions with DKA, 70% were diagnosed with type 2 diabetes, and 56% were females. 12% of admissions had a new diagnosis of diabetes, of which 51% had type 2 diabetes. Sepsis (48%), Non-adherence (26%), and diabetic foot infections (18%) were the most encountered precipitating factors for DKA in T1DM. As for T2DM, sepsis (52%), acute coronary syndrome (12%), and pancreatitis (8%) were the most precipitating factors for DKA. High urea levels, high creatinine levels, low phosphorous levels, low hemoglobin levels, and high platelet counts were associated with a longer hospital stay for type 1 diabetes. For type 2 diabetes, low pH on admission, old age, and high Hb A1c within 6 months of admission were factors associated with a prolonged hospital stay. The study found a significant peak of admissions for DKA in both type 1 and type 2 patients in the winter and spring months (Pearson P-value= 0.0013).

Conclusion

The results of the present study highlight the seasonal variation in the frequency of DKA hospitalizations. It also highlights sepsis as the most frequent precipitating factor of DKA in both type 1 and type 2 DM patients.

Comorbid autoimmune diseases and burden of diabetes-related complications in patients with type 1 diabetes from a Mediterranean area

AIM

To assess the prevalence of autoimmune diseases (AID) in patients with type 1 diabetes (T1D) and to evaluate whether the rate of diabetes-related complications differs depending on the presence of AID.

METHODS

Cross-sectional analysis of 13,570 T1D patients aged ≥ 18 years registered in the SIDIAP database. The association between AID and diabetes-related complications was assessed by multivariable logistic regression models.

RESULTS

The prevalence of AID was 18.3% with thyroid AID being the most common. Patients with T1D and AID were more often female and their current age, age of diabetes onset and diabetes duration were higher. Patients with only thyroid AID experienced a lower risk of peripheral artery disease (odds ratio [OR] = 0.51, 95%; confidence interval [CI] 0.31 to 0.81) and kidney disease (OR = 0.68, 95%; 95% CI 0.54 to 0.85), whereas patients with other AID had an increased risk of ischemic heart disease (OR = 1.48, 95%; 95% CI 1.04 to 2.06).

CONCLUSIONS

The burden of diabetes-related complications in patients with T1D differs according to the type of additional AID. The presence of diabetes complications is lower in those with autoimmune thyroid disease while the presence of other AID is associated with higher rates of ischemic heart disease.

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.

Clinical Characteristics and Degree of Glycemic and Cardiovascular Risk Factor Control in Patients with Type 1 Diabetes in Catalonia (Spain)

Background: This study aims to evaluate the clinical characteristics, complications, degree of glycemic control, and cardiovascular risk factor control in patients with type 1 diabetes in Catalonia (Northwest of Spain). Methods: Cross-sectional study using a database including clinical, laboratory, and treatment data. Patients with an ICD10 diagnosis of type 1 diabetes were included, excluding those treated with glucose-lowering agents other than insulin, or treated only with basal insulin two years after diagnosis. Results: 15,008 patients were analysed. Median IQR age was 42 (31–53) years, diabetes duration 11.8 (6.8–16.0) years, 56.5% men. Median (IQR) HbA1c was 7.9% (7.1–8.8). Microvascular complications were present in 24.4% of patients, 43.6% in those with a diabetes duration >19 years. In presence of known cardiovascular disease 69.3% of patients showed an LDL-C concentration >70 mg/dL, 37% had a systolic blood pressure >135 mmHg and 22.4% were smokers. Conclusions: This study provides a reliable snapshot about the clinical situation of a large population of patients with T1D in Catalonia, which is similar to that of other western areas. The lack of adequate control of cardiovascular risk factors in a significant proportion of patients with cardiovascular disease deserves a more detailed analysis and urges the need for improvement strategies.

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

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

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

Background

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

Methods

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

Results

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

Conclusions

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

Seasonal variation in hospital encounters with hypoglycaemia and hyperglycaemia

AIM

To assess whether rates of hospital encounters with hypoglycaemia and hyperglycaemia display seasonal variation.

METHODS

Time series analyses of the monthly rates of hospital encounters (emergency room visits or inpatient admissions) with hypoglycaemia and hyperglycaemia from 2003 to 2012 using linked healthcare databases in Ontario, Canada.

RESULTS

Over the study period, there were 129 887 hypoglycaemia and 79 773 hyperglycaemia encounters. The characteristics of people at the time of their encounters were similar across the seasons in 2008 (median age 68 years for hypoglycaemia encounters and 53 years for hyperglycaemia encounters; 50% female; 90% with diabetes). We observed moderate seasonality in both types of encounters (R² autoregression coefficient 0.58 for hypoglycaemia; 0.59 for hyperglycaemia). The rate of hypoglycaemia encounters appeared to peak between April and June, when on average, there was an additional 49 encounters per month (0.36 encounters per 100 000 persons per month) compared with the other calendar months (5% increase). The rate of hyperglycaemia encounters appeared to peak in January, when on average, there was an additional 69 encounters per month (0.50 encounters per 100 000 persons per month) compared with the other calendar months (11% increase).

CONCLUSIONS

In our region, there is seasonal variation in the rate of hospital encounters with hypoglycaemia and hyperglycaemia. Our findings may help to highlight periods of vulnerability for people, may inform future epidemiological studies and may aid in the appropriate planning of healthcare resources.

Incidence of childhood-onset type 1 diabetes in Biscay, Spain, 1990-2013

OBJECTIVE

To identify the incidence rate (IR) and epidemiologic trends of childhood type 1 diabetes mellitus (T1DM) in children aged 0 to 14-yr-old from 1990 to 2013, in the north of Spain (Biscay).

SUBJECTS AND METHODS

A prospective-retrospective study was performed. Capture-recapture method was used: primary cases were ascertained from hospital register and a secondary independent data source was obtained from diabetes associations and public health plan database. Age and sex-standardized incidence rates were calculated using direct method, assuming an equal distribution in each age/sex group. In order to identify and analyse trends the period studied was divided into two (1990-2001 and 2002-2013) 11-year periods. The 95% confidence interval (CI) was estimated assuming the Poisson distribution.

RESULTS

A total of 399 new cases were identified throughout the study. Mean age at diagnosis was 8.9 ± 3.7 yr. Completeness of ascertainment was 99.1%. Mean annual age-standardized IR was 10.7 (95% CI: 9.6-11.7). The mean incidence for the 0-4, 5-9 and 10-14 age groups was 5.1, 14.6 and 13.2 per 100,000 children/yr, respectively. The incidence rate trend in the whole group was not statistically significant. In the 10-14 age group we found a yearly average increase (2.5% [CI 95% 0.4-4.6]; P < 0.05) and analysing by sex, this statistically significant incidence trend was observed only in boys. We did not find a seasonal onset pattern.

CONCLUSIONS

The IR did not increase in this population during the period studied unlike the results in other Spanish regions and European Countries.

Temporal variation of diabetic ketoacidosis and hypoglycemia in adults with type 1 diabetes: A nationwide cohort study

BACKGROUND

Seasonality in health outcomes has long been recognized for conditions such as colds and flus. The aim of the present study was to determine whether hospitalizations for acute complications of type 1 diabetes (T1D) vary by month and season.

METHODS

An observational study was performed of national administrative health data. Hospitalizations for acute complications in adults (aged ≥18 years) with T1D were identified using ICD-10 (Canadian revision) codes between 2004 and 2010. Monthly and seasonal counts per year were determined for the study period. For each acute complication, the ratio of the number of observed hospitalizations/expected number of hospitalizations was calculated for each month and season per year, adjusting for varied lengths of month, season, and year.

RESULTS

In all, there were 21 568 hospitalizations for diabetic ketoacidosis (DKA) and 5349 hospitalizations for hypoglycemia during the study period. December had higher than expected hospitalizations for DKA and March had higher than expected hospitalizations for hypoglycemia. There did not appear to be variation for either DKA or hypoglycemia hospitalizations by season.

CONCLUSIONS

The results of the present study suggest temporal variation in hospitalizations for DKA and hypoglycemia, and therefore signal important times of patient vulnerability. Potential mechanisms underlying this pattern warrant further examination. Prevention strategies and resources for patients with T1D may need to be increased at specific times during the year.

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.

[Epidemiology of type 1 diabetes mellitus in children in Spain]

INTRODUCTION

Epidemiological studies in many regions and countries have contributed to determining the epidemiology of type 1 diabetes (T1DM) in children less than 15 years old. Studies in many regions of Spain have been published, but the national incidence is not really known.

MATERIAL AND METHODS

A review was made of the publications on the epidemiology of T1DM in Spain, selecting the references on patients less than 15 years old.

RESULTS

Many epidemiological studies on T1DM in almost all regions in Spain have been published. The methodology of these studies is heterogeneous, with variations in geographical definition, duration, period of study, limit of age, and data collection. The incidence rates are variable, from 11.5 cases per 100,000/year in Asturias to 27.6 in Castilla-La Mancha. Some studies report the percentage of diabetic ketoacidosis at the time of diagnosis, which is usually in the range of 25-40%.

CONCLUSIONS

Although there have been various epidemiological studies on T1DM in almost all regions in Spain, the methodology is heterogeneous. The mean incidence of T1DM in children less than 15 years old in Spain, stimated from the selected studies is 17,69 cases per 100,000/year. T1DM registers need to be created and updated, using standardized methodology, to get more reliable data of the epidemiology of T1DM in Spain in the near future.

Insulin resistance, low-grade inflammation and type 1 diabetes mellitus

To assess the relationships between insulin resistance and low-grade inflammation in subjects with type 1 diabetes mellitus (T1DM) who do not have clinical macrovascular complications. A total of 120 subjects diagnosed with T1DM 14 years before were evaluated for the following: (1) sex, age, body mass index, waist-to-hip ratio (WHR), blood pressure, smoking, alcohol intake, insulin dose, HbA1c and lipid profile; (2) microvascular complications; (3) plasma concentrations of soluble fractions of tumour necrosis factor-α receptors type 1 and 2, interleukin-6, adiponectin, leptin and high-sensitivity C-reactive protein (hs-CRP); and (4) insulin resistance (estimation of the glucose disposal rate-eGDR). Those subjects with an eGDR below the median of the same sex group were classified as insulin resistant and the others as insulin sensitive. Insulin-resistant men, compared to the insulin-sensitive, had higher WHR (0.89 ± 0.08 vs. 0.83 ± 0.05; P < 0.01), higher systolic [121 (118-125) vs. 114 (108-120) mmHg; P = 0.01] and diastolic [73 (66-80) vs. 67 (70-73) mmHg; P = 0.02] blood pressures, higher HbA1c values [8.7 (8.1-9.9) vs. 7.5 (7.2-8.0) %; P < 0.01] and higher hs-CRP concentrations [1.16 (0.61-3.20) vs. 0.49 (0.31-0.82) mg/dl; P = 0.01], but no other significant differences between groups were found. Insulin-resistant women had higher WHR and HbA1c values, compared to the insulin-sensitive, but they did not have any other differences. In men, hs-CRP correlated significantly with WHR and HbA1c (r = 0.363; P = 0.016 and r = 0.317; P = 0.036, respectively), after adjusting for age, alcohol intake, smoking and microvascular complications. Insulin-resistant men with T1DM have an increase in plasma concentrations of hs-CRP. Central obesity and HbA1c are its main determinants.

Gender differences and temporal variation in the incidence of type 1 diabetes: results of 8012 cases in the nationwide Diabetes Incidence Study in Sweden 1983-2002

OBJECTIVES

To establish the gender difference amongst newly diagnosed type 1 diabetic patients aged 15-34 years, considering age at diagnosis, temporal trend and seasonal variation at time of diagnosis.

STUDY DESIGN

A population-based prospective study with a mean annual population at risk of 2.3 million.

SETTING

All departments of medicine, endocrinology and paediatrics and primary health care units in Sweden.

SUBJECTS

Incident cases of diabetes aged 15-34 years at diagnosis 1983-2002. MEASURE INSTRUMENT: Basic characteristics of patients at diagnosis were reported by the diagnosing doctor on a standardized form. Level of ascertainment was estimated at 80-90%.

RESULTS

Amongst all incident cases (n = 8012), 74% was diagnosed with type 1 diabetes. The mean annual incidence rate of type 1 diabetes was 12.7/100,000, in men 16.4/100,000 and in women 8.9/100,000. The incidence of type 1 diabetes decreased slowly by increasing age but was in all age groups higher in men, yielding an overall male/female ratio of 1.8. In both genders the incidence of type 1 diabetes decreased in average of 1.0% per year. A seasonal pattern with significantly higher incidence during January-March and lower during May-July was seen in both genders.

CONCLUSIONS

A clear male predominance of type 1 diabetes was seen in all ages. The temporal trend and the seasonal pattern was similar in men and women. Hence, internal factors related to the gender rather than differences in the exposure to environmental factors seem to explain the consistent male-female bias in the postpubertal risk of developing type 1 diabetes.

Epidemiology and genetic risk of type 1 diabetes among children in Aragon community, Spain

The incidence of type 1 diabetes in children from Aragon (a population of the North of Spain) is reported determining the relations between the onset of type 1 diabetes and gender, age at diagnosis, genetic risk (HLA class II genes) or climatology factors. The population at risk was all 0-14 year-old inhabitants. Patients were identified from five sources: hospitals, primary assistance, endocrinologists, diabetic associations and diabetes camps. The degree of ascertainment was 98.93%. HLA genetic study was performed. Annual incidence was 16.4 per 100,000 per year (95% CI: 14.7-18.2). This incidence was significantly higher in males than in females, 18.7 versus 14.2 (p<0.02), and increased with age. The haplotypes (DR3)-DQB1*0201/(DR4)-DQB1*0302 and (DR3)-DQB1*0201/(DR7)-DQB1*0202 conferred the highest risk of type 1 diabetes. A relative high incidence of type 1 diabetes mellitus has been demonstrated in the Northeast of Spain, and it does not support south-to-north incidence gradient in Europe. Haplotypes that conferred a higher risk of disease agree with those founded in other Caucasic populations.

Incidence and prevalence of type 1 diabetes in children aged <15 yr in Castilla-Leon (Spain)

OBJECTIVES

To determine the incidence and prevalence of type 1 diabetes in children younger than 15 yr in the Autonomous Community of Castilla-Leon (Spain).

RESEARCH DESIGN AND METHODS

All type 1 diabetic cases with onset at <15 yr of age were recorded during 2003-2004. Identified case subjects were ascertained from several sources and the capture-recapture method was used to estimate the completeness of ascertainment. For prevalence, all patients younger than 15 yr with type 1 diabetes at the beginning and at the end of the study were identified.

RESULTS

Over the study period, 130 children aged 0-14 yr were diagnosed with type 1 diabetes. The average observed incidence of type 1 diabetes in this population was 22.22/100 000/yr (95% CI 14.57-29.81). Age-standardized incidence was 22.01/100 000/yr (95% CI 18.18-25.83). The highest incidence was observed in the 5-9 yr age-group (32.45/100 000/yr, 95% CI 24.31-40.59). The prevalence at the beginning and at the end of the study was 1.01/1000 and 1.18/1000, respectively.

CONCLUSION

Castilla-Leon appears to have one of the highest incidences of childhood type 1 diabetes in Spain, with recent incidence approaching those of some northern European countries.

Seasonal variation in the diagnosis of type 1 diabetes in south-east Sweden

With the aim to survey the seasonal pattern of diagnosis of type 1 diabetes we included all 1903 children <16 years of age and who had been diagnosed with type 1 diabetes between 1977 and 2001 in the south-east of Sweden. To investigate the seasonal pattern a mixture of two cosine functions was included in a logistic regression model. There was a clear seasonal variation over the years (p<0.001). Children in the oldest age group (11-15 years) showed the most obvious seasonal variation (p<0.001). Children with a short duration of symptoms had about the same seasonal variation as children with a long duration. Both children with and without an infection 3 months prior to diagnosis showed significant seasonal variation (p<0.001) although the seasonal pattern differed between the two groups (p<0.001). As the incidence of diabetes increased during the 25 years the study period was divided into periods of 5 years and it was only during the two last periods that significant seasonal variation occurred. There is a clear seasonal variation in diagnosis of type 1 diagnosis in children and the results suggest that children with a less aggressive disease process at diagnosis were most responsible for this variation. Children with and without prior infection showed a different seasonal pattern.

Epidemiología de la diabetes tipo 1 en menores de 15 años en las provincias de Castilla y León

INTRODUCTION

The incidence of type 1 diabetes shows wide geographical variability and heterogeneity. The aim of this study was to determine the incidence and prevalence of type 1 diabetes in children and adolescents ages less than 15 years in the different provinces of Castilla-León.

MATERIAL AND METHODS

To determine incidence, all new cases of type 1 diabetes with onset under 15 years of age in 2003-2004 were obtained. Incidence was expressed as the crude value with the corresponding confidence interval and as standardized incidence. The capture-recapture method was used to calculate the completeness of ascertainment. To determine prevalence, all cases of type 1 diabetes in persons ages less than 15 years at 31 December 2004 were obtained.

RESULTS

Incidence showed wide variability among the different provinces of Castilla-León. The highest values were found in Segovia (38.77/100,000/year), Valladolid (32.07/100,000/ year) and Avila (23.21/100,000/year) and the lowest in Zamora (8.14/100,000/year). Incidences were highest in the 5-9 years age group in all provinces except Burgos. Prevalence was highest in Segovia (1.54/1,000), Valladolid (1.41/1,000), Avila (1.38/1,000) and Zamora (1.32/1,000) and lowest in Burgos (0.91/1,000).

CONCLUSIONS

Castilla-León seems to have one of the highest incidences of type 1 diabetes in Spain; several of its provinces have values similar to those in Northern Europe.

La diabetes mellitus en España: mortalidad, prevalencia, incidencia, costes económicos y desigualdades

OBJECTIVE

Describing the situation of diabetes mellitus (DM) in Spain from a public health perspective.

MATERIAL AND METHOD

manual review of books and other documents on diabetes mellitus in Spain was conducted. In addition, a specific research of articles published using MeSH terms diabetes mortality, prevalence, incidence, cost, inequalities and Spain was conducted in Medline through Internet (PubMed). Minimun Basic Data Set was utilized as source for complication description by Communities Autonomus.

RESULTS

DM is one of the leading cause of mortality and the third one in women. With regard to Autonomous Communities, Canary Islands, Ceuta y Melilla and Andalusia show the greatest mortality with a downward trend. Diabetics present greater mortality than non diabetic patients, being complications the main cause of the over-mortality, especially ischemic heart disease. Estimations of prevalence for DM2 range from 4.8% to 18.7% and for DM1, from .08% to .2%. In pregnancy, it has been noted a prevalence ranging from 4.5% to 16.1%. With respect to incidence per year, it is estimated a range from 146 to 820 per 100,000 inhabitants for DM2 and a range from 10 to 17 new cases annually per 100,000 inhabitants for DM1. Costs for DM1 show very different results, averaging between 1,262 and 3,311 euro per people and year. There are differences for DM2 costs as well, averaging between 381 and 2,560 euro per patient and year. Total costs estimated range from 758 to 4,348 euro per person and year. Relationship between a low socioeconomic level (LSL) and DM2 risk has been proved. Moreover, it has been noted that the less LSL the worse is the disease control, coupled with a greater frequency and more frequent factors of DM2 risk.

CONCLUSIONS

The knowledge about the situation of the DM as a Public Health problem in Spain is limited. Mortality data available does not gather its real magnitude, and prevalence, incidence, costs and inequalities research are very poor and hardly comparable. In spite of this degree of incertitude, we can state that DM is an important public health problem with a continuous increase, especially DM2, if the appropriate prevention and control measures are not taken.

Diabetic neuropathy is associated with activation of the TNF-alpha system in subjects with type 1 diabetes mellitus

OBJECTIVE

The development of diabetic neuropathy (DN) is predicted by cardiovascular risk factors associated with insulin resistance. As inflammation seems to be implicated in the pathogenesis of insulin resistance, we investigated whether subjects with type 1 diabetes mellitus (T1DM) and DN have an increase in plasma concentrations of inflammatory proteins involved in insulin resistance.

DESIGN

Cross-sectional. Patients One hundred twenty subjects, all diagnosed with T1DM 14 years before.

MEASUREMENTS

(1) Sex, age, body mass index, waist-to-hip ratio (WHR), blood pressure, smoking, alcohol intake, insulin dose, HbA1c and lipid profile; (2) DN (peripheral and cardiac autonomic), retinopathy and nephropathy; (3) plasma concentrations of soluble fractions of tumour necrosis factor alpha receptors 1 and 2 (sTNFR1 and sTNFR2), interleukin-6, high-sensitive C-reactive protein, adiponectin and leptin; and (4) insulin resistance (by way of a mathematical estimation of the glucose disposal rate - eGDR-).

RESULTS

Thirty-six subjects had DN and 84 did not. Subjects with DN received higher insulin doses (57.6 +/- 16.7 vs. 49.2 +/- 15.0 IU/day; P = 0.008) and had higher WHR (0.85 +/- 0.07 vs. 0.81 +/- 0.10; P = 0.007) and HbA1c values (8.5 (7.6-9.6) vs. 7.7 (7.3-8.9)%; P = 0.049) than subjects without DN. They also had higher values of sTNFR1 (2.42 +/- 0.60 vs. 1.96 +/- 0.66 microg/l; P = 0.001) and sTNFR2 (4.73 +/- 1.33 vs. 4.14 +/- 1.09 microg/l; P = 0.015), and were more insulin resistant (eGDR values: 7.28 (5.83-8.03) vs. 8.30 (7.17-9.03) mg kg(-1) min(-1); P = 0.003). The relationship between DN and either sTNFR1 or sTNFR2 remained essentially unchanged after adjusting for several confounders, including glycaemic control, WHR, lipid profile, blood pressure and other microvascular complications (OR for sTNFR1: 2.592 (1.222-5.498), P = 0.013; OR for sTNFR2: 2.124 (1.258-3.587), P = 0.005).

CONCLUSIONS

The activity of the TNF-alpha system is increased in subjects with type 1 diabetes mellitus and diabetic neuropathy, regardless of their glycaemic control and cardiovascular risk factors associated with insulin resistance. These results suggest that TNF-alpha may play a pathogenic role in the development of diabetic neuropathy.

Incidence of Type 1 diabetes in children in Cáceres, Spain, during 1988-1999

AIM

To determine the incidence of Type 1 diabetes in Cáceres in children less than 14 years of age. We tested for differences in incidence by age, sex and season at diagnosis.

METHODS

All Type 1 diabetes cases with onset <14 years of age between 1988 and 1999 were recorded retrospectively. Pediatric Unit registries provided the primary source of ascertainment. The secondary independent data source was based on the registries of local Diabetic Associations, diabetes camp records and guarantee cards of blood-glucose meters. We used the capture-recapture method for ascertainment.

RESULTS

During the 12-year period, 137 new cases of Type 1 diabetes were identified. Completeness of ascertainment was 99.2%. Average annual observed incidence was 16.8/100,000/year (95% C.I. 14.1-19.8). Age-standardised incidence (world population): 16.5/100,000/year (95% C.I. 13.9-19.6). Average annual incidence for 0-4, 5-9 and 10-13-year-old groups: 12.7/100,000 (95% C.I. 8.8-17.9), 18.2/100,000 (95% C.I. 13.7-23.8) and 19.1/100,000 (95% C.I. 14.2-25.1). The highest age-specific annual incidence rate was found in the 10-13-year age group. There was a seasonal onset pattern, with the highest incidence in autumn and winter. November was the month with the highest number of cases (22/137).

CONCLUSION

Cáceres has a moderately high incidence of Type 1 diabetes in children less than 14 years of age, similar to that found in other more developed and densely populated regions of Spain, and in the range of other countries of northern Europe. These data do not support the hypothesis of a decrease in the incidence of the disease from north to south over Europe.

[Glycemic control and new prospects on insulinotherapy in diabetes mellitus type 1]

Except for contraindications, current treatment of DM1 is based on what we know as insulin intensive treatment. This modality includes the utilization of rapid insulins for controlling the postprandial hyperglycemic peaks, and insulins of intermediate or slow action with the objective of contributing some basal levels of insulin (bolus/basal type therapy). Although the intensive treatment does not avoid completely the appearance nor the progression of the microvascular complications, improvement of glycemic control reduces the risk of developing microvascular complications approximately between 35% and 75%, and its worsening diminishes the risk between 50% and 75%. New insulin analogues has possibly many and obvious advantages. New insulin analogues are a potentially effective alternative in the intensive treatment of the patients with DM1, and they represent the best way for implementing a <<bolus-basal>> type therapeutic regimen. Its balanced and individualized application can contribute for improvement metabolic control, including a reduction in the incidence of hypoglycemia.

Clinical characteristics at onset of Type 1 diabetes in children diagnosed between 1977 and 2001 in the south-east region of Sweden

To survey clinical characteristics at diagnosis for children diagnosed with Type 1 diabetes during 25 years in the south-east part of Sweden we included all 1903 children < 16 years of age and who had been diagnosed between 1977 and 2001 in the south-east region of Sweden. A nurse or doctor in the diabetes team obtained information from medical records. Over the 25 years the mean duration of symptoms prior to diagnosis was 17.8 +/- 26.4 days and the mean glucose level at diagnosis was 23.6 +/- 9.7 mmol/l. Three percent of the children (n = 50) had a pH value < or = 7.1. The youngest children (0-5 years) had shorter duration of symptoms, lower blood-glucose levels and less often had ketonuria than the oldest children (11-15 years) but more often suffered from infections prior to diagnosis. The proportion of children diagnosed in the group 0-5 years of age increased over the study-period, apart from the last 5 years, while children with pH value < or = 7.3 decreased significantly as did the proportion of children with ketonuria or infection. The clinical characteristics at diagnosis of diabetes are heterogeneous, especially in the oldest age group. Some characteristics varied with time.

Incidencia y características clínicas al manifestarse la diabetes mellitus tipo 1 en niños de Galicia (España, 2001-2002)

OBJECTIVE

To determine the epidemiology, clinical manifestations and laboratory results at onset of type 1 diabetes mellitus in children aged 0-14 years from January 2001 to December 2002.

PATIENTS AND METHODS

All children younger than 14 years old living in Galicia (Spain) and admitted to one of the hospitals of the Galician health service with a diagnosis of type 1 diabetes mellitus from 2001-2002 were included. A questionnaire was administered to collect data on age, sex, place of residence, associated autoimmune disorders, family history, clinical manifestations before onset and their duration, and biochemical parameters at diagnosis (glycemia, HbA1c, pH and bicarbonate).

RESULTS

A total of 109 children were diagnosed (48 girls and 61 boys). The annual incidence (per 100,000 pediatric inhabitants) was 17.6. A higher frequency was found in winter (33 %) and spring (26 %) than in autumn (21.3 %) and summer (20.3 %). Admissions were most frequent among 5-9 year-olds (40.3 %), followed by 10-14 year-olds (33 %) and 0-4 year-olds (26.6 %). The most frequent clinical manifestations were polyuria and polydipsia (95.8 %). Nycturia or enuresis and weight loss were also described. The mean duration of these symptoms was 25.4 days in the group of children aged between 10-14 years old, 21.7 days in those aged 5-9 years old and 13.6 days in those younger than 4 years old. In one-third of the patients, the initial presentation was ketoacidosis.

CONCLUSIONS

The incidence of type 1 diabetes mellitus among Galician children is high. The interval between the onset of the first symptoms and diagnosis is long. In 31.7 % of the patients, the initial event was ketoacidosis.

Interferon alpha--a potential link in the pathogenesis of viral-induced type 1 diabetes and autoimmunity

The incidence of type 1 diabetes has been rapidly rising. Environmental factors such as viruses have been implicated as a possible agent accounting for this rise. Enteroviruses have recently been the focus in many research studies as a potential agent in the pathogenesis of type 1 diabetes. The mechanism of viral infection leading to beta cell destruction not only involves multiple pathways but also the cytokine-interferon alpha (IFN-alpha). Our hypothesis is that activation of toll receptors by double-stranded RNA or poly-IC (viral mimic) through induction of IFN-alpha may activate or accelerate immune-mediated beta cell destruction. Numerous clinical case reports have implicated that IFN-alpha therapy is associated with autoimmune diseases and that elevated serum IFN-alpha levels have been associated with type 1 diabetes. In multiple animal models, given specific genetic susceptibility, poly-IC can induce insulitis or diabetes. Therapeutic agents targeting IFN-alpha may potentially be beneficial in the prevention of type 1 diabetes and autoimmunity.

The epidemiology of Type 1 diabetes mellitus is not the same in young adults as in children

AIMS/HYPOTHESIS

This prospective study examined the epidemiology of Type 1 diabetes in young adults in Europe.

METHODS

We ascertained incident cases of Type 1 diabetes in the 15 to 29 years (both inclusive) age group throughout Europe over a period of 2 years. Diabetes registries in nine countries, in which incidence rates for Type 1 diabetes in the 0 to 14 age group were available, took part. Incidence rates were estimated per 100000 person years and standardised for sex and age. Cumulative incidences per 1000 from birth to age 30 were estimated. Heterogeneity between centres was tested with a Poisson regression model.

RESULTS

A total of 2112 diabetes cases were ascertained in 1996 and 1997, of which 61.4% were considered to be Type 1 diabetes. Completeness of ascertainment varied from 70 to 90%. Standardised incidence varied from 4.8 per 100000 person years to 13.4 per 100000 person years. The male-female ratio was estimated to be one or more, and in the 25 to 29 age group 1.5 or more in all countries. Cumulative incidences for males and females indicate that the former exceeds the latter from age 24. In the two centres with highest childhood incidence, this applied already from 14 years of age.

CONCLUSIONS/INTERPRETATION

The incidence of Type 1 diabetes in adults is lower than in children and the range of incidence is also reduced, with a less than threefold variation in adults, against an eightfold variation in children. There is a male excess in incidence, especially in the age group 25 to 29 years.

The relationship between immune-mediated Type 1 diabetes mellitus and ethnicity

OBJECTIVE

To determine the proportion of adults with newly diagnosed Type 1 diabetes that had immune-mediated disease (IMD).

SUBJECTS AND METHODS

Two hundred fifteen patients with hyperglycemia and symptoms of insulin deficiency were screened for antibodies [islet cell antibodies (ICA), insulin autoantibodies (IAA), and glutamatic acid decarboxylase antibodies (GADA(65))] and HLA DR/DQ markers of IMD.

RESULTS

The mean age was 34 years and the mean BMI was 30.0 kg/m(2); 21.8% were non-Hispanic white (NHW), 27% were Latin American (LA), 47.9% were African American (AA), and 3.3% of other (OT) ethnic origins. Sixty individuals (28%) had one or more autoantibodies [Ab(+)]: 62% of NHW, 19% of AA, and 19% of LA. BMI was significantly lower (P<.01) in Ab(+). At least one HLA-DQ allele for susceptibility for IMD was identified in 52% of Ab(+).

CONCLUSIONS

These results suggest that islet cell autoantibodies and HLA markers of susceptibility for IMD are frequent in individuals of varying ethnic backgrounds, older age at onset, and higher body weight. Since early insulin therapy could delay what may otherwise be rapid progression to complete insulinopenia in patients with IMD, screening of adult diabetic patients for IMD at diagnosis may be of benefit to long-term management.

Diabetes autoimune em adultos: características clínicas e autoanticorpos

Avaliamos a prevalência dos anticorpos anti-insulina (IAA), anti-decarboxilase do ácido glutâmico (anti-GAD), anti-ilhota de Langerhans (ICA) e as características clínicas e metabólicas de 66 pacientes com diabetes mellitus (DM) de início na idade adulta (47,2±11,6 anos) e duração do DM de 14,3±8,4 anos. RESULTADOS: ICA foi positivo em 10 casos (10 a 640U JDF), três deles também positivos para anti-GAD (15,6 a 113,5U/ml) e um deles para IAA (naqueles sem terapia insulínica). 15,2% dos pacientes tinham um ou mais autoanticorpos, com maior prevalência para ICA. Os pacientes com e sem autoanticorpos não diferiram quanto à apresentação clínica do DM ou à prevalência de complicações. Apenas os níveis de colesterol foram menores no grupo anticorpo positivo (205,2±49,6 vs. 247,1±61,3mg/dl; p<0,05). CONCLUSÃO: 15,2% dos pacientes com DM de início na idade adulta tinham um ou mais autoanticorpos, com maior prevalência para ICA. A determinação de autoanticorpos é necessária para o diagnóstico do DM autoimune.

[Clinical, metabolic, immunologic and genotypic characteristics in non-pediatric patients with type 1A diabetes mellitus. Onset and short-term prognosis]

BACKGROUND AND OBJECTIVE

Around 50% of new cases of type 1 diabetes mellitus (DM1) are seen in subjects aged above 15 years. It is of particular interest the characterization of such a population.

THE AIMS OF OUR STUDY WERE

a) to characterize a group of non-pediatric subjects with DM1 at the onset of the disease; b) to evaluate the prognosis of the disease under conventional intensive insulin therapy, and c) to investigate the presence of mutations in the HNF-1* gene in those subjects who did not display pancreatic autoimmune markers.

SUBJECTS AND METHOD

All subjects with an age >= 15 and 35 years recently diagnosed DM1 (1998-2001) were included in the study. Pancreatic cell function was assessed by glucagon test (at onset and at 12 months). The presence of pancreatic autoantibodies, GAD, IA2 and IAA was evaluated. HLA class II genes and the 10 exons of HNF-1* gene were analyzed from genomic DNA.

RESULTS

We studied 86 subjects (32 women, 23.9 [5.3] year-old). Eighty percent of subjects were positive for any of the studied autoantibodies. Alone or in combination, GAD was positive in 68.6% of subjects, IA2 in 45.3% and IAA in 27.9% of them. Most frequent haplotype was DRB1*0301-DQA1*0501-DQB*0201. There were no differences with regard to clinical, metabolic or genetic characteristics among those subjects with or without presence of pancreatic autoantibodies (at onset and at 12 months). We did not find mutations in the HNF-1* gene in any of the subjects included in our study. After 12 months of follow-up, cell function remained unaltered in comparison with that observed at the onset of the disease.

CONCLUSIONS

Clinical, immunological and HLA characteristics of a non-pediatric DM1 population are in agreement with expected results. The absence of pancreatic autoimmune markers neither rules out the existence of type 1A diabetes mellitus nor is associated with mutations in the MODY-3 gene. A therapeutic programme using conventional intensified insulin treatment prevents the impairment of insulin secretory capacity for a short-term follow-up.

Evaluación del proceso y los resultados de la atención a los pacientes diabéticos en un hospital

For the purpose of establishing a specific information system in order to identify the diabetic patients looked after in the hospital and evaluate the processes and the clinical outcomes obtained, a prospective descriptive study was designed--in the Corporació Parc Taulí of Sabadell (Barcelona)--about the diabetic patients cared starting in January 1998, through a clinical registry and other hospital sources of information. Seven hundred and fifty-five patients were identified, and the completeness of the registry was 98%. It was feasible the integration of the registry of admissions with that of the laboratory, that of the discharges from hospital, that of pharmacy and the specific clinical registry. An evaluation of the glycemic control was made in around 90% of the patients, and the registry of the organic explorations was higher than 87%. Although it was not possible in this study, the incorporation of the information from the primary care would complete the follow-up of the patients.

Dynamic changes in the trends in incidence of type 1 diabetes in children in Hungary (1978-98)

OBJECTIVE

To determine the recent trends in incidence, to analyze the age and geographic distribution, as well as the seasonal pattern of type 1 diabetes in Hungarian children aged 0-14 yr for the period from 1978 to 1998.

METHODS

Primary ascertainment of cases was by retrospective (1978-88) and by prospective (1989-98) registration using hospital notifications. The level of ascertainment was estimated by the capture-recapture method. The temporal trend was estimated by fitting Poisson regression models to the yearly incidence data. Roger's test was used to investigate possible seasonal variation in time of diagnosis. Heterogeneity between geographic areas was assessed by Poisson regression.

RESULTS

A total of 2616 patients (1214 in the first 11 yr, 1402 in the remaining 10 yr) were identified; the male:female ratio was 0.93. The overall standardized incidence rate was 7.87 (95% CI = 7.57-8.18) per 100,000 person-yr, the lowest in the youngest (0-4 yr) and highest in the oldest (10-14 yr) age group. There was an increasing trend in incidence with a largest relative annual increase in the youngest age group. Seasonal and regional variations in incidence were also observed.

CONCLUSION

Our 21-yr study shows dynamic changes in incidence of childhood type 1 diabetes in Hungary, probably reflecting changes in the environment.

[Epidemiology of diabetes and its non-coronary complications]

Diabetes mellitus is among the diseases with great impact on health and society, not only for its high prevalence but also for its chronic complications and high mortality. The most precise method to investigate the prevalence of diabetes is by oral glucose tolerance testing. In Spain, the prevalence of diabetes in the 30-65 year-old population is estimated to be 6.5% among 30-to-65- year old, and 10.3% among the 30-to-89 year-old population. The ratio of known to unknown diabetes ranges from 1:3 to 2:3. The incidence of diabetes mellitus type 2 in Spain is 8/1000 persons per year, and the incidence of type 1 is 11 to 12 cases per 100,000 persons per year. The prevalence of chronic complications varies according to type of diabetes, time since onset and degree of metabolic control: neuropathy 25%, retinopathy 32% and nephropathy 23%. Diabetes is one of the most important causes of death in Spain, occupying third place for women and seventh for men.

Islet autoantibodies in the prediction of diabetes in school children

In 1987 serum was collected from 1031 non-diabetic schoolchildren in the Southeast area of Sweden with the aim of evaluating islet autoantibody status (ICA, GADA and IA2-ab) in the prediction of diabetes in schoolchildren. The clinical development of Type 1 diabetes in the children was assessed in 1994 and 1997. The combination of ICA, GADA and IA2-ab were found in four subjects whereas six had two and 35 children one of these antibodies. After 10 years, six of the 1031 children had developed clinical diabetes and five of these six children were positive for islet antibodies. Two were positive for all three antibodies, two were positive for ICA and GADA, and one was positive for GADA. Among the individual autoantibodies, ICA showed the highest positive predictive value (29%) whereas the predictive value for the combination of two autoantibodies was highest for GADA and ICA (40%). Thus, GADA and ICA measurements may be a rational approach to detect schoolchildren at risk for developing diabetes.

[Incidence of type 1 diabetes mellitus in the Canary Islands (1995-1996). Epidemiologic Group of the Canary Society of Endocrinology and Nutrition]

OBJECTIVE

To prospectively evaluate the incidence of type 1 diabetes mellitus in patients up to 30 years of age in the Canary Islands during 1995 and 1996.

PATIENTS AND METHODS

The population under study consisted of 744,444 inhabitants in the 0-29 year old group and 302,293 in the 0-14 year old group. The capture-recapture method was used for estimating the probability of ascertainment. Hospital records and endocrinologists' reports were the primary source, whereas reports from the Canary Diabetes Association reports and sales of blood glucose monitors were the secondary source.

RESULTS

A total of 223 new cases of type 1 diabetes mellitus were detected during the study period. The degree of ascertainment was 90.1%. The observed incidence rates were 23.2 per 100,000 per year for the 0-14 year old group and 9.2 per 100,000 per year for the 15-29 year old group. The overall incidence rate was 15 per 100,000 per year for the entire group. The highest incidence was found in the 10-14 year old group. The incidence in males was higher than in females, and particularly significant in the 15-29 year old group. No seasonal onset pattern was detected.

CONCLUSIONS

A high rate of incidence of type 1 diabetes mellitus was observed in this study in children aged less than 15 years living in the Canary Islands.

The rising incidence of childhood type 1 diabetes in New South Wales, Australia

OBJECTIVES

1. To determine the incidence of type 1 (insulin dependent) diabetes in children aged 0-14 years who were resident in the state of New South Wales, Australia over the period 1992-1996. 2. To analyse the trends in incidence over the period 1990-1996.

METHODS

Primary ascertainment of patients was performed using a prospective incidence register established in 1990. The secondary source of ascertainment was the National Diabetes Supply Scheme, a government subsidised scheme for diabetic supplies.

RESULTS

There were 1,230 patients identified over the five-year period. Using the capture-recapture method, ascertainment was estimated to be 99% complete. The lowest incidence occurred in 1992 (16.9 per 10(5) person years) and the highest incidence was in 1995 (21.7 per 10(5)). The crude incidence of IDDM from 1990-1996 was 17.8 per 10(5) and there was a statistically significant rise in the incidence of type 1 diabetes over this period (p=0.0003). The annual incidence has increased on average by 3.2% per year since 1990.

CONCLUSION

The incidence of childhood type 1 diabetes in NSW has increased significantly since 1990.

HLA class II immunogenetics and incidence of insulin-dependent diabetes mellitus in the population of Cantabria (Northern Spain)

HLA class II genes were analyzed to study IDDM susceptibility in Cantabria (Northern Spain). Patients showed highly significant increases in DRB1*0301 (RR = 4.581, p < 0.00005), DRB1*0401 (RR = 2.6, p < 0.05), DRB1*0402 (RR = 8.78, p < 0.05) and DRB1*0405 (RR = 14.73, p < 0.005). Highly significant diferences were in the DQA1*0301 (RR = 3.62, p < 0.000005) and DQA1*0501 (RR = 2.13, p < 0.05) alleles. DQB*0201 (RR = 4.1, p < 0.00005) and DQB1*0302 (RR = 5.42, p < 0.000005) alleles were also significantly increased. A significant increase in DRB1*0402-DQA1*0301-DQB1*0302 (RR = 16.18, p < 0.05), DRB1*0405-DQA1*0301-DQB1*0302 (RR = 16.12, p < 0.05), DRB1*0301-DQA1*0501-DQB1*0201 (RR = 4.58, p < 0.00005) and DRB1*0401-DQA1*0301-DQB1*0302 (RR = 4.36, p < 0.005) was apparent in the diabetic group, while the DRB1*1501-DQA1*0102-DQB1*0602 and DRB1*1401-DQA *0104-DQB1*05031 protective haplotypes (RR = 0.17 and 0.09, p < 0.0005 and 0.05, respectively) were significantly lower in patients. The absence of Asp57 and the presence of Arg52 were associated with disease in a dose-dependent manner. Several genotypes encoding the identical DQalpha52/DQbeta57 phenotype carried very different RRs. Finally, the Cantabrian population has the highest incidence of IDDM reported for Spain (15.2 of 100.000 in the 0-14 age group, Poisson's 95% CI: 10.6-19.3).

Month of birth and risk of developing insulin dependent diabetes in south east Sweden

Environmental factors very early in life may be important for later development of insulin dependent diabetes. Because several of these factors, such as infections, vary with season, we predicted a difference in birth pattern compared with the general population among children who develop diabetes. In a population based study we analysed all 1248 children from seven paediatric departments in the south east part of Sweden to evaluate whether there is such a relation. There was a significant difference in birth pattern in patients with diabetes compared with the general population. Children who developed diabetes at the age of 10-15 years accounted for most of this difference. Boys had a more pronounced difference in birth pattern than girls. Children diagnosed with diabetes during years of high incidence, as well as children with an infection before diagnosis of diabetes, showed a significantly different birth pattern compared with the background population. These results indicate that there is a difference in birth pattern in children who develop diabetes compared with the background population. This supports the theory that environmental factors early in life play a role in the development of diabetes many years later.

Migrant populations and the incidence of type 1 diabetes mellitus: an overview of the literature with a focus on the Spanish-heritage countries in Latin America

Type 1 diabetes mellitus (DM) is a 'chronic' autoimmune disorder leading to the destruction of the pancreatic beta cell. The natural history of diabetes includes a long subclinical (prediabetes) period. The pathogenesis is multifactorial and characterized by the interaction of environmental factors, with predisposing genes, most of which are associated with the HLA DR DQ loci. The relatively recent development of worldwide incidence registries for Type 1 DM has allowed us to compare the epidemiological results obtained in most parts of the world. This approach is particularly valuable in analysing the effects of migration of populations from one area of the world where the incidence of Type 1 DM is different (usually lower) to a new geographic setting. Properly designed migrant studies may be valuable in uncovering whether the genetic background remains more important than the new 'exposure' as illustrated by the Sardinian migration to Lazio and Lombardy. The presence of some putative 'protective' environmental exposures or the absence of those prevalent in the country of origin may explain the usually lower Type 1 DM incidence observed in most countries (Chile, Peru, Mexico) sharing a 'Spanish caucasoid genetic pool', and even in relatively genetically homogeneous groups such as Japanese populations migrating to Hawaii. In fact, the disease is caused by both genetic and environmental factors and to convince the scientific community of this fact is a primary responsibility for epidemiologists.

Prevalence of diabetes in Catalonia (Spain): an oral glucose tolerance test-based population study

The goal of this study was to investigate the prevalence of diabetes mellitus and impaired glucose tolerance in the adult population of Catalonia and study their association with obesity, central obesity, hypertension and smoking habit. A random sample of 3839 subjects aged 30-89 years participated in this cross-sectional study: 2214 subjects underwent a health examination with oral glucose tolerance test (OGTT) and 1625 were interviewed by phone. Diabetes prevalence (known and unknown) in the 30-89-year-old population was 10.3%, (95% CI: 9.1-11.6). In this age group, the prevalence rates of known diabetes, unknown diabetes and impaired glucose tolerance were 6.4, 3.9 and 11.9% in men and 6.9, 3.4 and 11.9% in women. The age adjusted prevalence to the world population for the 30-64-year-old age group was 6.1% (7.1% in men and 5.2% in women).The factors significantly associated with diabetes were age, obesity, hypertension and family history of diabetes. The high ratio of previously known diabetic cases to newly discovered ones, specially in the oldest age group, suggests good levels of awareness and medical services. The prevalence in Catalonia is similar to that observed in other Mediterranean countries.

Increase in IDDM incidence in Bulgarian children (1974-1995)

The incidence of insulin-dependent diabetes mellitus (IDDM) in children on the Balkan peninsula varies between 2.45 and 10.00/100,000. The present study aimed to assess the trends in the IDDM incidence in children 0-14 years for a 22-year period in Eastern Bulgaria. The data were collected on the basis of the Varna Paediatric Diabetes Registry, both retrospectively and prospectively, with ascertainment of the primary source up to 98.8%. The mean annual IDDM incidence was 6.32/100,000 (95% CI 5.91-6.78), with the incidence in towns significantly higher than in villages: 7.24 vs 4.58/100,000, p < 0.0001. A linear trend of increase in the incidence with time was found, applying Poisson regression analysis. According to the model the age-adjusted incidence rose by 1.9% annually. The analysis revealed a significant linear trend of increase for children living in towns and for those aged 10-14 years.

Regional variability in the epidemiology of childhood diabetes in Italy

The incidence rates of IDDM in Italy show remarkable variability. Sardinia, a region with the second highest incidence rate in the world, co-exists with other regions with lower rates. We review and compare epidemiologic data on the incidence of childhood-onset IDDM in Italy. papers published from 1980 to 1996 reporting incidence data in Italian areas were found by search of Medline and non-indexed Italian journals. The incidence data found cover only 57% of the Italian population. The analysis of our results shows how difficult it is to make a careful study of epidemiology of IDDM in Italy. The RIDI (the Registry for Insulin-dependent Diabetes mellitus in Italy) project started in 1996 according to international guidelines. The aims is to coordinate local IDDM registries, to promote the start of new registries in uncovered areas, and to standardize registration and data collection.

Incidence of type I diabetes mellitus in Navarre, Spain (1975-91)

The aim of this study was to ascertain the incidence of Type 1 diabetes mellitus in Navarre, an autonomous community in northern Spain. Subjects were patients who presented with diabetes between 1975 and 1991, age range 0-16 years, resident in Navarre at the onset of symptoms. Endocrinologists in outpatient centres and hospitals (both public and private) in Navarre were the primary source of data, while secondary sources were: independent general practitioners, health centre paediatricians and the Child-Youth Diabetics Parents' Association of Navarre. The degree of ascertainment was 97.8%. Average annual incidence of diabetes detected was 9.54/100000 (95% CI 8.2-11.1) in the 0-14 year-old group. The least incidence was observed in 1976 and highest in 1990. The incidence in males (9.71/100000) was higher than in females (7.83/100000). The highest incidence was observed in the 10-14 year-old group (13.70/100000) when analysed by groups. No seasonal variation in the onset of diabetes was observed. These results suggest a significant increase in the incidence of type 1 diabetes between 1975 and 1991.

Long-term patterns in seasonality of insulin-dependent diabetes mellitus diagnosis in Austrian children

The analysis of the seasonal pattern of incidence of childhood insulin-dependent diabetes mellitus in Austria was carried out among cases where the child was under the age of 15 when diagnosed between 1979 and 1993. The cases are registered in the nationwide population-based Austrian insulin-dependent diabetes mellitus registry. Seasonal variation was compared between boys and girls and between three 5-year age groups. We also tested whether the seasonal pattern changed over the 15-year observation period. We found a significant seasonal variation among boys aged 10-14 and girls aged 5-14, while in the 0-4 years age group no seasonal pattern could be demonstrated. Two peaks in incidence were identified during a calendar year (February-March and September-October) for girls aged 5-14. For boys aged 10-14, a yearly cycle was found with a peak in January and October. An extension of the Poisson regression model for testing seasonality by Jones et al. was developed to allow for estimation of a time-dependent amplitude of the seasonal component. The annual incidence rate increased by 36% during the observation period, but no significant change in seasonal pattern could be demonstrated.

Incidence of insulin-dependent diabetes (IDDM) and non-insulin-dependent diabetes (NIDDM) (0-34 years at onset) in Benghazi, Libya

The incidence of insulin-dependent diabetes (IDDM) and non-insulin-dependent diabetes (NIDDM) in Benghazi, Libya in the < 35-year age group during the period 1981-1990 are reported. Incidence data for IDDM were based on prospective registration of patients while incidence data for NIDDM were based on analysis of files. Case ascertainment of IDDM cases was estimated to be > 95%. Incidence of total diabetes (IDDM and NIDDM) (per 100000 population) was significantly higher in females (43.8; 95% confidence Interval (CI) 40.6-47.2) than in males (28.9, 26.6-31.3) (P < 0.001). The overall incidence rates of IDDM and NIDDM were 9.0 (CI, 8.1-10.0) and 27.3 (CI, 25.4-28.2), respectively. Rates of IDDM were 9.4 (CI, 8.1-10.9) among males and 8.5 (CI, 7.3-10.0) among females. Rates of NIDDM were 19.6 (CI, 18.1-22.2) among males and 35.3 (CI, 32.4-37.8) among females. IDDM patients showed a female predominance in the 0- to 14-year age range (P > 0.05) and a male predominance in the 15- to 34-year age range (P > 0.05). NIDDM showed equal incidence in males and females in the 0- to 14-year age range and twofold higher incidence in females than in males in the 15- to 34-year age group (P < 0.001). Yearly variation and seasonality of onset were not significant in IDDM cases (P > 0.05). Fifty-six percent of NIDDM cases were obese compared to only 6% of IDDM cases. The study revealed that diabetes mellitus is a common chronic disease in children and young Libyan Arabs. It has shown that NIDDM in Benghazi is twofold higher in females than in males in the 15- to 34-year age group. It has also shown that age per se is not a reliable criterion for the classification of diabetes into IDDM and NIDDM.

Incidence of IDDM during 1988-1992 in Zagreb, Croatia

The objective of this study was to determine the incidence of insulin-dependent diabetes mellitus (IDDM) in the population of Zagreb, Croatia, during 1988-1992. A centralized diabetes registry was the primary source of data, while secondary sources were used to assess ascertainment. A total of 282 new cases of IDDM were diagnosed in the study period, the primary and secondary sources identifying annually 93-100% of the cases. The annual incidence rate ranged from 5.6 per 100,000 to 6.6 per 100,000. Early fatality in persons older than 50 years was the major cause of underascertainment. The incidence peaked in the 10-14 years age group (12.4 per 100,000), and remained stable after age 24 years. Males had a significantly higher incidence in the 5-9 and 24-44 years age groups. In the 45-54 years age group, females had a significantly higher incidence. No seasonality was observed. Despite the war conditions in Croatia, the low overall IDDM incidence rates did not change significantly during the study period.