Anders Green

Trends in the incidence of childhood-onset diabetes in Europe 1989-1998

Abstract.Aims/hypothesis: To study the epidemiology of childhood-onset (Type I) insulin-dependent diabetes mellitus in Europe, the EURODIAB collaborative group in 1988 established prospective, geographically-defined registers of all children diagnosed with Type I diabetes under 15 years of age. This report is based on 24 423 children, registered by 36 centres, with complete participation during the period 1989–1998 and representing most European countries with a population coverage of approximately 20 million children. Methods: Multiple sources of ascertainment were used to validate the level of ascertainment. Trends in Type I diabetes incidence during the period were analysed using Poisson regression with the results from the 36 centres pooled into nine regions. Results: The standardised average annual incidence rate of Type I diabetes varied more than tenfold between centres. Overall, the annual increase in incidence was 3.2 % (95 %-CI: 2.7 %, 3.7 %), being highest for children in the 0–4-year age-group 4.8 % (3.8 %, 5.9 %) and lowest for children in the 10–14-year age group 2.1 % (1.4 %, 2.8 %). However, the absolute increases in Type I diabetes were roughly similar in the three age-groups of 0–4, 5–9 and 10–14 years. Central Eastern Europe showed the highest increase whereas Sardinia and Northern Europe (except Finland) showed no evidence of an increase. For all age-groups relatively fewer cases had disease onset during the summer months, especially the 10–14-year age-group. Conclusion/interpretation: The extremely large range of incidence rates within Europe has been confirmed. The incidence rate is generally increasing but is more pronounced in some regions than in others. Seasonality at disease onset is apparent even in the youngest age-group. [Diabetologia (2001) 44 [Suppl 3]: B 3–B 8]

Variation by age group and seasonally at diagnosis of childhood IDDM in Europe

SummaryRecent data provided by the EURODIAB ACE study group have confirmed wide variation in the incidence of insulin-dependent diabetes mellitus (IDDM) across Europe. The aim of this report is to compare age-specific incidence and seasonality at clinical onset of IDDM between study regions. Using a uniform methodology, the EURODIAB ACE framework ascertained 3,168 newly-diagnosed cases of IDDM in children under the age of 15 years during 1989–1990. Eighteen percent of the cases were age 0–4 years at diagnosis, 34 % were age 5–9 years and 48 % were age 10–14 years. Poisson regression analysis suggested that there were highly significant statistical differences in incidence between the three age groups and between the 24 regions. Although incidence rates in the 0–4 year and 5–9 year age groups varied from region to region in a similar fashion, the pattern of variation in the older age group was different. Seasonality of diagnosis conformed to a sinusoidal model with a peak occurring in winter, a feature which was consistently observed in both sexes and in all age groups. However, a statistically significant heterogeneity in the seasonal distribution was present among regions, those in Scandinavia showing the smallest relative amplitude. The first insulin injection was given the same day or the day after diagnosis in 93 % of the cases for whom data were available.

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

Aims/hypothesisThis prospective study examined the epidemiology of Type 1 diabetes in young adults in Europe.MethodsWe 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.ResultsA 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/interpretationThe 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.

A Cox regression model for the relative mortality and its application to diabetes mellitus survival data.

A Cox-type regression model for the ratio between the mortality in a cohort and that in a reference population is introduced. By means of the model it is possible to include in the survival analysis both individual (possibly time-dependent) characteristics for the study cohort and changing trends in the mortality in the reference population. This is particularly relevant in long-term follow-up studies where there may be considerable changes in the mortality in the reference population. Estimation procedures in the model are discussed and large-sample properties of the estimators are outlined. The model is applied to the analysis of two sets of data concerning the survival among insulin-dependent diabetics in Denmark.

Rising prevalence of diabetes: evidence from a Danish pharmacoepidemiological database.

The prevalence of diabetes has increased worldwide. We have undertaken an epidemiological analysis of drug-treated diabetes in a well defined community. We present estimates of prevalence, incidence, and mortality of patients with such diabetes during 1993-, based on data for all 470000 people living in the county of Fyn, Denmark. Although prevalence increased (odds ratio: female, 1.026 [95% CI 1.020-1.032]; male, 1.041 [1.036-1.047]), mortality in those treated declined (rate ratio: female, 0.976 [95%CI 0.952-1.001]; male, 0.966 [0.943-0.990]). We did not identify a clear trend for incidence. Future research into the causes of rising diabetes prevalence should take this fall in mortality into account to avoid incorrect conclusions about the relation between western lifestyle and the growing number of diabetics.

The changing world demography of type 2 diabetes

In recent years it has been estimated that the current global prevalence of type 2 diabetes amounts to about 150 million patients. Projections suggest that by the year 2025 the number of prevalent patients in the world will reach approximately 300 million. It is assumed that the increase in the number of patients will be most pronounced in nations currently undergoing socio‐economic development including increasing urbanization. The technique used to provide these estimates is based on results from available, contemporary survey results, combined with expected future trends in demographic indicators. We suggest that the currently available methods for the estimation of the future global burden of type 2 diabetes mellitus yield underestimates. Further modifications and validity tests of the modelling techniques are necessary in order to develop a reliable instrument to globally monitor the effects of the struggle against the diabetes problem. Copyright

Music in minor activates limbic structures : a relationship with dissonance?

Using functional magnetic resonance imaging, we contrasted major and minor mode melodies controlled for liking to study the neural basis of musical mode perception. To examine the influence of the larger dissonance in minor melodies on neural activation differences, we further introduced a strongly dissonant stimulus, in the form of a chromatic scale. Minor mode melodies were evaluated as sadder than major melodies, and in comparison they caused increased activity in limbic structures, namely left parahippocampal gyrus, bilateral ventral anterior cingulate, and in left medial prefrontal cortex. Dissonance explained some, but not all, of the heightened activity in the limbic structures when listening to minor mode music.

Empirical Bayes Age-Period-Cohort Analysis of Retrospective Incidence Data

We analyse the (age, time)-specific incidence of diabetes based on retrospective data obtained from a prevalent cohort only including survivors to a particular date. From underlying point processes with intensities corresponding to the (age, time)-specific incidence rates the observed point pattern is assumed to be generated by an independent thinning process with parameters (assumed known) depending on population density and survival probability to the sampling date. A Bayesian procedure is carried out for the optimal adjustment and comparison of isotropic and anisotropic smoothing priors for the intensity functions, as well as for the decomposition of the intensity on the (time, age) Lexis diagram into the three factors of age, period and cohort.

No association between birth weight and Type 1 diabetes mellitus – a twin-control study

Aims To investigate, by means of a twin‐control study, whether there is a relationship between birth weight and Type 1 diabetes mellitus.

The Frederiksberg Heart Failure Study: Rationale, Design and Methodology, with Special Emphasis on the Sampling Procedure for the Study Population and Its Comparison to the Background Population

Background/Objective: The aim of the Frederiksberg Heart Failure Study was to describe the epidemiology of heart failure in the general population among persons older than 50 years. This paper describes some aspects of the methodology of this study, especially regarding population sampling. Methods: From 1997 to 2000, a random sample of 1,088 women and men aged 50–89 years from the municipality of Frederiksberg (city of Copenhagen, Denmark) were invited to participate in the study; 764 subjects (70.2%) were examined (57% female). To optimize scientific information across age groups, we used age-stratified sampling, attempting to have at least 150 subjects in each age decade, i.e. 50–59 years (n = 240), 60–69 years (n = 208), 70–79 years (n = 190) and 80–89 years (n = 126). Each participant filled in a questionnaire and was submitted to an echocardiographic examination, an ECG and collection of blood samples. The group of invited subjects (divided into participants and nonparticipants) was compared with the background population with regard to hospital admissions due to cardiovascular diseases and mortality 1 year before and 1 year after sampling. Results: As a result of the sampling strategy, the sampling proportion increased from 2.86% in the age class 50–59 years to 4.43% in the age class 80–89 years, with no evidence of a sex difference. The participation proportion systematically decreased with age, from 75.2% in the age class 50–59 years to 57.5% in the age class 80–89 years, with no sex difference. Both participants and nonparticipants had admission rates for cardiovascular diseases similar to that of the background population during the year before sampling. However, the rate of admission was significantly increased (p = 0.025) during the year after the time of sampling, and this applied equally to participants and nonparticipants. The 1-year mortality rate was increased in the sample after sampling (p = 0.014). However, participants had a 1-year mortality rate very close to that of the background population, whereas nonparticipants had a 1-year mortality rate more than three times higher than that of the participants (p < 0.001). In terms of methodology, the echocardiographic assessment was examined as follows: the interobserver variability between two independent observers in measuring the ejection fraction by means of echocardiography was calculated, and overall agreement was found to be 93.2% (kappa value = 0.786), corresponding to a very good level of agreement. The interobserver coefficient of variation was 4.9%. Conclusion: In this population-based study, the increased mortality and admission rates among nonparticipants suggest that subjects who agree to participate in a study on heart failure are a biased sample, in that they represent relatively healthy subjects. The fact that the participation rate declined with age indicates a systematic age effect in this bias. Standard methods to assess how representative of the corresponding background population a study population is should be agreed upon for future studies.