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

Association between interferon-induced helicase (IFIH1) rs1990760 polymorphism and seasonal variation in the onset of type 1 diabetes mellitus

BACKGROUND

Infections, mostly of viral origin, may contribute to the seasonal variation in the onset of type 1 diabetes mellitus (T1DM). The rs1990760 (A>G, Ala946Thr) polymorphism (GG genotype) of the interferon induced helicase (IFIH1), a virus recognition receptor, confers a modest protection for T1DM. The aim of our study was to evaluate a possible association between this IFIH1 polymorphism and the seasonal variation in the onset of T1DM.

MATERIALS AND METHODS

The IFIH1 rs1990760 polymorphism was genotyped in 1055 patients of Central-Eastern European ancestry with T1DM (median age at diagnosis: 8.2 [interquartile range, IQR 4.8-11.8] years). T1DM onset was recorded in monthly intervals.

RESULTS

The IFIH1 genotype distribution was the following: 436 patients (41.3%) had AA genotype, 483 patients (45.8%) had AG genotype, and 136 patients (12.9%) had GG genotype. Significant seasonal variation in manifestation of T1DM (highest rate in winter and lowest rate in summer period) was observed in the total cohort (n = 1055), irrespective of gender. The disease predisposing AA genotype was more frequently found among new cases with onset in summer vs in those with onset in winter (44.3% vs 37.9%); conversely, the protective GG genotype was less frequent (9.3% vs 12.9%, respectively; P = .0268 for trend). Significant effect of genotype (P = .0418) was found on the seasonal variability of T1DM onset in the total cohort.

CONCLUSIONS

The IFIH1 rs1990760 polymorphism seems to be associated with the seasonal manifestation of T1DM. Our findings suggest that this virus receptor gene may contribute to T1DM manifestation primarily in the summer period.

Prevalence of undiagnosed abnormal glucose tolerance in adult patients cared for by general practitioners in Hungary. Results of a risk-stratified screening based on FINDRISC questionnaire

BACKGROUND

The prevalence of type 2 diabetes mellitus is rapidly increasing, worldwide and also in Hungary. Timely diagnosis and early treatment could be aided by targeted screening. Recognizing this, the Hungarian Diabetes Association initiated a risk-stratified screening with the involvement of primary care physicians.

MATERIAL/METHODS

In the first phase of screening, the FINDRISC questionnaire was completed, followed by an oral glucose tolerance test (OGTT) for those with a score of ≥12. Between September 1, 2010 and March 31, 2011, 70,432 non-diabetic adults, who visited their general practitioners for any reason, were involved in the screening. Of these, 68,476 questionnaires proved to be suitable for processing.

RESULTS

From the questionnaires, 28,077 (41.0%) had a score of ≥12. A valid OGTT was performed in 22,846 cases; of this group 3,217 subjects (14.1%) had elevated fasting glucose levels, 5,663 (24.8%) had impaired glucose tolerance, and 1,750 (7.6%) had manifest, previously undiagnosed, diabetes mellitus. Overall, from the valid OGTT group, 46.5% subjects had some degree of glucose intolerance.

CONCLUSIONS

Based on the FINDRISC questionnaire, the risk-stratified screening for diabetes mellitus proved to be simple and cost-effective method for the early detection of carbohydrate metabolism disorders. Using this method, the prevalence rate of previously undiagnosed abnormal glucose tolerance was high in adult patients cared for by general practitioners in Hungary.

Regional differences in incidence and clinical presentation of type 1 diabetes in children aged under 15 years in Croatia

AIM

To determine regional differences in the incidence, incidence trends, and clinical presentation of type 1 diabetes in children under the age of 15 years in Croatia in a 9-year period (1995-2003).

METHODS

We included the patients who had been diagnosed with the disease and had started the insulin treatment before they were 15 years old. Regional differences between eastern, central, and southern Croatia were observed. The gross incidence was expressed by the number of newly diagnosed type 1 diabetes patients in 100000 children of the same age and sex per year, ie, for the 0-14 age group, and for the 0-4, 5-9, and 10-14 subgroups.

RESULTS

The highest incidence was observed in southern Croatia (10.91 per 100000/y) and the lowest in central Croatia (8.64 per 100000/y), and in eastern Croatia the incidence was 8.93 per 100000/y. All three regions showed a growing incidence trend, which was significant only in eastern and southern Croatia. There was 35.9% of patients with diabetic ketoacidosis in eastern Croatia, 41.7% in central Croatia, and 31.28% in southern Croatia.

CONCLUSION

Croatian regions show differences in the incidence, incidence trends, and disease presentation of type 1 diabetes. A further follow-up is needed to establish whether the regional differences are a consequence of the population dynamics in the observed period or they will continue to exist, pointing to differences in environmental risk factors.

Twenty-one years of prospective incidence of childhood type 1 diabetes in Hungary--the rising trend continues (or peaks and highlands?)

The aim of this study was to examine secular trends in the incidence of type 1 diabetes in children aged 0-14 yr in Hungary over the period 1989-2009. Newly diagnosed children with type 1 diabetes aged 0-14 yr in Hungary were prospectively registered from 1989 to 2009. Primary ascertainment of cases was by prospective registration using hospital notifications. Case ascertainment was over 96% complete using the capture-recapture method. Standardized incidence rates were calculated and secular trends estimated using Poisson regression analysis. In Hungary during 1989-2009 a total number of 3432 children were identified, giving a standardized incidence rate of 12.5 [95% confidence interval (CI) 12.1-12.9] per 100,000 person yr. The overall incidence rate has doubled from 7.7 (95% CI 6.4-9.15) per 100,000 per yr in 1989 to 18.2 (95% CI 15.7-20.9) per 100,000 per yr in 2009. A significant linear trend in incidence (p < 0.001) has been observed over time, with a mean annual increase of 4.4%. The increase in incidence was present in both genders and in all age groups, with the largest relative increase in the youngest age group (6.2%; p < 0.001). The incidence of type 1 diabetes in Hungarian children continues to increase, with the highest rate in the very young. Although it seems that transient periods of stabilization followed by increases in incidence are apparent, the long-term trend continues to be steadily upward. Incidence of childhood type 1 diabetes is a dynamic process, probably reflecting the changes of the environmental exposures and continued registration is necessary to recognize these trends.

Prediction and prevention of type 1 diabetes mellitus: initial results and recent prospects

Epidemiological studies indicate that the incidence and prevalence of type 1 diabetes mellitus is rising worldwide. The increase in incidence has been most prominent in the youngest age group of childhood. Prediction of type 1a autoimmune diabetes can be established by a positive family history or by genetic, immunological or metabolic markers. Prevention of type 1 diabetes can be implemented at three different levels of pathogenesis: primary prevention in individuals without any sign of beta-cell damage, secondary prevention in individuals with signs of beta-cell destruction and tertiary prevention in patients with newly diagnosed type 1 diabetes. In the recent years our knowledge of the disease pathogenesis has grown quickly and worldwide several new prevention trials have been started. Probably immune intervention of type 1 diabetes will prove to be the most effective. Orv. Hetil., 2011, 152, 1916–1921.

“Always up or peaks and highlands?” Incidence of childhood type 1 diabetes in Hungary (1989–2009)

Aim of this study was to examine secular trends in the incidence of type 1 diabetes in children aged 0–14 years in Hungary over the period 1989–2009. Methods: Newly diagnosed children with type 1 diabetes aged 0–14 years in Hungary were prospectively registered from 1989 to 2009. Standardized incidence rates were calculated and secular trends were estimated using Poisson regression analysis. Results: Between 1989 and 2009 a total number of 3432 children were identified, giving a standardized incidence rate of 12.5 (95%CI 12.1–12.9) per 100 000 person/year. The overall incidence rate has doubled from 7.7 (95%CI 6.4–9.15) per 100 000 per year in 1989 to 18.2 (95%CI 15.7–20.9) per 100 000 per year in 2009. A significant linear trend in incidence (p<0.001) has been observed over time, with a mean annual increase of 4.4%. The increase in incidence was present in both genders and in all age groups, with the largest relative increase in the youngest age group (6.2%; p<0.001). Conclusion: The incidence of type 1 diabetes in Hungarian children continues to increase, with the highest rate in the very young. Orv. Hetil., 2011, 152, 1692–1697.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Steep increase of incidence of childhood diabetes since 1999 in Austria. Time trend analysis 1979-2005. A nationwide study

In a prospective population-based incidence study all newly diagnosed type 1 diabetic patients 0-<15 years of age were registered by the Austrian Diabetes Incidence Study Group. The nationwide incidence of type 1 diabetes between 2000-2005 was compared with the previously published incidence rates. Long-term trends as well as seasonal trends were estimated by Poisson regression models. A total of 3,599 incident cases (1,908 boys; 1,691 girls) were identified. Case ascertainment was >92%. The overall incidence rate doubled from 7.3 (95% CI; 6.8-7.9)/100,000 in the period 1979-84 to 14.6 (95% CI, 13.7-15.4)/100,000 in the time period 2000-2005. A significant increase during the observation period of 26 years could be demonstrated in all age groups and both sexes (p<0.01), with the steepest increment during the last 5 years. Until 1994 the incidence rate in children 0-<5 years was rather stable, but afterwards increased dramatically with 9.2% (95% CI, 5.2-13.4) annually. Despite this steep increase in time trend, we did not observe a seasonal variation in this age group (0-<5) in contrast to significant seasonal variations in the groups 5-<10 and 10-<15 years of age. Over the past 26 years incidence of type 1 diabetes in childhood increased clearly in Austria. The steepest rise was observed in the last 5 years and in the younger age groups.

Diabetes incidence in 0- to 14-year age-group in Italy: a 10-year prospective study

OBJECTIVE

The Registry for Type 1 Diabetes Mellitus in Italy (RIDI) Study Group was established to coordinate the registries of type 1 diabetes in Italy. This report is based on 3,606 children younger than 15 years diagnosed with type 1 diabetes and prospectively registered during 1990-1999 by nine centers, covering >35% of the Italian population.

RESEARCH DESIGN AND METHODS

Registries were pooled in four geographic macro-areas: north, central, south, and insular. The completeness of registration was assessed by the capture-recapture method. Poisson regression analysis was used to evaluate temporal trend in incidence.

RESULTS

Large variations in incidence were confirmed not only between Sardegna and the mainland but also among peninsular areas. In Sardegna, there was an excess of boys (the boy-to-girl incidence ratio was 1.4). The overall incidence showed average increases of 3.6% (P <0.001) and 3.7% (P <0.001) per year in peninsular Italy and in Sardegna, respectively. Significant increases in incidence rates were found in boys aged 10-14 years (6.7%, 95% CI 0.5-13.3) and in girls aged 5-9 years (6.6%, 0.5-13.1) living in the southern area. The incidence rate also increased in boys aged 10-14 years (5.0%, 0.3-10) and in girls aged 0-4 years (4.9%, 0.8-9.1) living in Sardegna.

CONCLUSIONS

Italy is a country with large geographical variations in incidence rates of type 1 diabetes. However, the rates are evenly increasing both in the mainland and Sardegna, suggesting that similar environmental factors are operating over populations that have different genetic backgrounds.

Type 1 diabetes among sardinian children is increasing: the Sardinian diabetes register for children aged 0-14 years (1989-1999)

OBJECTIVE

The Sardinian type 1 diabetes register represented the basis to determine the most recent trends and the age distribution of type 1 diabetes incidence among Sardinians <15 years of age during 1989-1999. Part of the data (1989-1998) has been already published by the EURODIAB Group with a lower completeness of ascertainment (87%). The geographical distribution of type 1 diabetes risk was also investigated.

RESEARCH DESIGN AND METHODS

The new cases of type 1 diabetes in children aged 0-14 years in Sardinia were prospectively registered from 1989 to 1999 according to the EURODIAB ACE criteria. The completeness of ascertainment calculated applying the capture-recapture method was 91%. Standardized incidence rates and 95% CI were calculated assuming the Poisson distribution. Trend of type 1 diabetes incidence was analyzed using the Poisson regression model. Maps of the geographical distribution of type 1 diabetes risk for the whole time period and separately for 1989-1994 and 1995-1999 were produced applying a Bayesian method.

RESULTS

A total of 1214 type 1 diabetic patients were registered yielding to an overall age- and sex-standardized incidence rate of 38.8/100000 (95% CI 36.7-41.1). There was a male excess with an overall male-to-female ratio of 1.4 (1.3-1.8). The increase of incidence during the 11 years analyzed was statistically significant (P = 0.002) with a yearly increasing rate of 2.8% (1.0-4.7). No evidence of an effect of age and sex on this trend has been found. The geographical distribution of type 1 diabetes relative risk (RR) showed that the highest risk areas are located in the southern and central-eastern part of the island and the lowest risk in the northeastern part, even if most of these differences were not statistically significant. This geographical distribution seemed to remain mainly the same between 1989-1994 and 1995-1999.

CONCLUSIONS

The homogeneity of diabetes risk and the increase of incidence over the age-groups in the Sardinian population stress the role of an environmental factor uniformly distributed among the genetically high-risk Sardinians.

Diabetes in the young: a paediatric and epidemiological perspective

The spectrum of diabetes in the young has widened; it now includes monogenic diseases, for example the various forms of permanent and transient neonatal diabetes and MODY as well as the emerging obesity-associated Type 2 diabetes in late childhood, but the main form is still Type 1 diabetes. Age-related major medical, physiological, social and emotional problems make the clinical management of diabetes in children and adolescents a difficult task for the physician and the family. Overall glycaemic control remains moderate or poor despite a treatment schedule, which interferes with several elements of "normal" childhood. There is an up to tenfold geographical variation in the incidence of childhood Type 1 diabetes within Europe with relatively stable incidence rates in some countries (mainly northern), but dynamic increases in incidence in other countries (mainly central European).A number of nongenetic (environmental) factors have been associated with the risk of Type 1 diabetes. Among these, perinatal factors, early nutrition, growth and vaccinations, atopic diseases and vitamin D are discussed in detail. The important interplay between genes, organism and environment is illustrated with new genetic data supporting the importance of environmental pressures in the evolution of this major disease.Although Type 1 diabetes usually accounts for only a minority of the total impact of diabetes in a population, it is the predominant form of the disease in younger age-groups in most developed countries. It is estimated that on an annual basis almost 100 000 children younger than 15 years of age develop Type 1 diabetes worldwide. The autoimmune destruction of the pancreatic beta cells in Type 1 diabetes leads to absolute insulin dependence and a high rate of complications typically occurring at a relatively young age. Therefore, Type 1 diabetes places a particularly heavy burden on the individual, the family and health services.