INAUGURAL MANIFESTATIONS OF TYPE-1 DIABETES-MELLITUS IN CHILDREN, ADOLESCENTS, AND ADULTS YOUNGER THAN 40 YEARS

Since 1989 all incident cases of type 1 diabetes mellitus (DM) and the ir first-degree relatives younger than 40 years are entered in the Bel gian Diabetes Registry. The data thus collected were used to analyze c linical and laboratory features at diagnosis in 581 insulin-dependent DM (IDDM) patients younger than 15 years and in 885 IDDM adolescents a nd adults aged 15 to 39 years. The incidence of IDDM was 11.8/100000 i n subjects younger than 15 years and 8.9/100000 in subjects aged 15 to 40 years. Before 15 years of age cases were evenly divided between ma les and females, whereas in the older group the male-to-female ratio w as 1.7. Median duration of symptoms (polyuria, polydipsia, weight loss , asthenia) at diagnosis was three weeks in patients younger than 15 y ears versus 8 weeks in those aged 15 to 40 years. Weight loss, astheni a, ketonuria, and beta-cell depletion as judged by C-peptide levels we re more marked in younger patients. Moreover after glycemic control ha d been achieved, the mean insulin dose was 0.75 U/kg in patients young er than 15 years versus only 0.44 U/kg in patients aged 15 to 40 years . At diagnosis, the subgroup of children younger than eight years of a ge had lower glycated hemoglobin and C-peptide levels than the subgrou p aged eight to 14 years. These data suggest that IDDM may be more agg ressive in children and adolescents than in adults. Potential relation s between the genetic and/or immunologic factors responsible for the h eterogeneity of type I DM and of patterns of presentation and clinical expression remain speculative.