[The incidence and initial symptoms of diabetes mellitus type 1 in 0-14-year-olds in the Netherlands, 1996-1999]

To determine the incidence and characteristics of type-1 diabetes mellitus (DM) in children aged 0-14 years during the period 1996-1999 and to compare this with previous measurements of the incidence.

Descriptive.

Data were collected via reports from all practicing paediatricians to the Dutch Paediatric Surveillance Unit and a questionnaire among members of the Dutch Diabetes Association. The incidence was calculated by the capture-recapture method, and the characteristics and symptoms of the children were determined from the questionnaires.

The incidence of DM type 1 among 0-14-year-olds increased to 18.6/100,000/year (95% CI: 17.7-19.4) compared to 11.1/100,000/year (10.5-11.7) in 1978-1980. The increase was highest in the youngest age group, 0-4 years. DM type 1 was diagnosed at an average age of 7.6 years (7.4-7.9) and in 1988-1990 at 9.2 years (9.0-9.5). The boy-girl ratio also increased. Children with a mother from Surinam, Turkey or The Netherlands Antilles had lower risk of DM type 1 while a higher risk was calculated for children from Moroccan and Somali mothers. In comparison with 1993-1994, there were less frequent lethargy or dehydration; lower average serum-glucose values, a better blood pH and less frequent ketonuria at the time of diagnosis. Treatment on an outpatient basis had increased. However, over the time span 1993-1999, Moroccan children (n = 108) showed dehydration, ketonuria and low blood-pH values more frequently than children of Dutch parents (n = 1825) and their hospital admission lasted longer.

The incidence of DM type 1 had increased and the disease manifested itself at a younger age. The clinical condition at time of diagnosis, however, was better. The incidence and clinical characteristics differed between children of different ethnic origin.