Epidemiology, Clinical Aspects, and Biology of IDDM Patients Under Age 40 Years: Comparison of data from Antwerp with complete ascertainment with data from Belgium with 40% ascertainment. The Belgian Diabetes Registry

Abstract

In Antwerp, the incidence rate of IDDM under age 15 years is intermediately high compared with the rates in other European regions. It is similar in the 15-39 years age-group, but with a marked male predominance. Demographic, clinical, and biological data show the same age-dependent heterogeneity as the data collected nationwide, with 40% ascertainment indicating the representativeness of the latter.

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

“…In the areas with intermediate childhoodonset diabetes incidence Catalonia had the same male excess pattern, whereas data from Sardinia, the English centres and the low-incidence areas Romania, Slovakia and Lithuania only showed a male excess from the age of 25 years. Studies from Belgium with a longer follow-up period have also found a male excess as described here [21,34].…”

“…In all nine centres the estimated male to female ratio of Type 1 diabetes incidence was greater than one in the 15 to 29 age group and greater than in children. In the age group 25 to 29 years the male to female incidence rate ratio was equal to or greater than 1.5 in all centres, although this was not statistically significant in Antwerp and Leicestershire, the two centres with the smallest study populations [21,31]. However, the Belgian Diabetes Registry has shown a significant difference between incidence rates in men and women (p<0.001) in the age range 15 to 39 years [21,32].…”

“…The epidemiology of Type 1 diabetes mellitus is not the same in young adults as in children 381 that the registry with 40% ascertainment was nevertheless representative [21]. However, we chose to use the smaller Antwerp registry for this EU project because high ascertainment is more important than representability of cases, when it comes to ensuring maximum reliability of incidence rate estimates.…”

“…A number of studies have reported a strong male preponderance in the incidence of Type 1 diabetes in adults [18,19,20,21,22,23,24,25,26,27]. In this respect young adults differ from children, for overall sex-specific differences in children are slight, although high-incidence populations tend to show male preponderance, and low-incidence populations (mostly non-European) show female preponderance [34].…”

“…Adult cases are characterised by a reduced frequency of HLA susceptibility haplotypes, as compared with children [1,16,17], and overall have less acute symptoms than children [1]. Male predominance is a further, unexplained feature of Type 1 diabetes in young adults [18,19,20,21,22,23,24,25,26,27]. This is in marked contrast to most other common immune-mediated conditions, which are typified by female preponderance [28].…”