Incidence, prevalence, and mortality of insulin-dependent (type 1) diabetes mellitus in Lithuanian children during 1983-98.

Aims/hypothesis: Our purpose is to analyze interrelations of the incidence, prevalence and mortality of childhood-onset insulin-dependent diabetes mellitus (type 1) in Lithuania.

Methods: Incidence and prevalence rates were based on the national type 1 diabetes register during 1983-98. The cohort study was performed to evaluate the standardized mortality ratios.

Results: The average incidence of type 1 diabetes during the 16-yr study period was 7.36 per 100,000/yr. For both males and females the highest incidence of type 1 diabetes was recorded in the 10-14 yr age group. The regression-based linear trends of the increase in incidence in various age groups and the annual percentage change for both genders was 2.05 (p = 0.0039) and the greatest regression slope is observed for both genders in the 10-14 yr age group. Regression-based linear trends in type 1 diabetes prevalence indicate an even growth in all age groups (3.47; p = 0.001), although the annual percentage change is most prominent in the 5-9 yr age group for girls (4.95%/yr) and in the 10-14 yr age group for boys (4.06%/yr). The standardized mortality ratio of all-cause mortality in people with diabetes is higher than in the common population 7.71 (p < 0.0001). The standard mortality ratio for all causes increases with longer diabetes duration.

Conclusion/interpretation: The significant increasing trend of incidence and prevalence during 1983-98 is observed. The annual percentage change is similar. The young patients with type 1 diabetes have a higher mortality risk.