Increased Risk of Childhood Type 1 Diabetes in Children Born After 1985

Abstract

OBJECTIVE—The incidence rate of childhood type 1 diabetes is thought to be increasing; however, Danish studies have not confirmed this. Using a national diabetes register initiated in 1996 and two previous regional incidence studies, we studied the age-specific incidence of type 1 diabetes over 30 years. Here, we describe the incidence rates of type 1 diabetes in Danish children from 1996 to 2000 and evaluate trends in age-specific incidence rates from 1970 to 2000. RESEARCH DESIGN AND METHODS—A nationwide registration of all newly diagnosed cases of type 1 diabetes among children under the age of 15 years was established in Denmark in 1996. Incidence rates of type 1 diabetes in Denmark were obtained from this register. Age-specific incidence rates were compared with data collected from 1970 to 1976 and from 1980 to 1984, both population-based studies using existing national routine registration of hospitalizations within the survey areas. Population data were obtained from Statistics Denmark. RESULTS—During the study period, 1,421 Danish children developed type 1 diabetes before the age of 15 years. The incidence rates by age-groups were: 12.7, 19.4, and 26.3 for the 0–4, 5–9, and 10–14 years age-groups, respectively, and 19.5 for the 0–14 years age-group per 100,000 in the period 1996–2000. An age-period-cohort analysis showed a modest drift effect (yearly increase) of 1.2% (0.7–1.8) from 1970 to 2000, and a significant birth cohort effect with an increased risk for children born after 1985 was observed. CONCLUSIONS—The incidence rate of type 1 diabetes is rising in children living in Denmark. The steep increase in the youngest age-group was explained by the increased risk for cohorts born at the beginning of the 1980s.

The Danish National Diabetes Register: trends in incidence, prevalence and mortality

“…The incidence rates in the younger age group in this study show a similar pattern to those reported in studies from the Danish Childhood Diabetes Register (DSBD), with a peak among girls about age 12 years and about 15 years for boys [17]. Furthermore, a study using pharmacological data to identify the diabetes population in the county of Fyn has also found an increased prevalence and decreased mortality rates in the same period [18].…”

Cumulative Incidence of Type 1 Diabetes in 10,168 Siblings of Finnish Young-Onset Type 1 Diabetic Patients

“…In this observational study, we did not have any data on exposure, either genetic or environmental. The markedly increased risk for siblings born in 1980 or later is in keeping with the incidence trend data from Finland and several European countries (23,(33)(34)(35). Although the data show differences in the risk of type 1 diabetes between birth cohorts, there might be some underestimation in the risk of type 1 diabetes in the earliest birth cohort.…”

Diabetes-associated HLA genotypes affect birthweight in the general population

“…The incidence of type 1 diabetes before 15 years of age is increasing [1,2], especially for children diagnosed at an early age [3][4][5][6][7]. HLA susceptibility genes are strongly associated with type 1 diabetes [8][9][10][11].…”