Regional differences in incidence and clinical presentation of type 1 diabetes in children aged under 15 years in Croatia

AIM: To determine regional differences in the incidence, incidence trends, and clinical presentation of type 1 diabetes in children under the age of 15 years in Croatia in a 9-year period (1995-2003). METHODS: We included the patients who had been diagnosed with the disease and had started the insulin treatment before they were 15 years old. Regional differences between eastern, central, and southern Croatia were observed. The gross incidence was expressed by the number of newly diagnosed type 1 diabetes patients in 100 000 children of the same age and sex per year, ie, for the 0-14 age group, and for the 0-4, 5-9, and 10-14 subgroups. RESULTS: The highest incidence was observed in southern Croatia (10.91 per 100 000/y) and the lowest in central Croatia (8.64 per 100 000/y), and in eastern Croatia the incidence was 8.93 per 100 000/y. All three regions showed a growing incidence trend, which was significant only in eastern and southern Croatia. There was 35.9% of patients with diabetic ketoacidosis in eastern Croatia, 41.7% in central Croatia, and 31.3% in southern Croatia. CONCLUSION: Croatian regions show differences in the incidence, incidence trends, and disease presentation of type 1 diabetes. A further follow-up is needed to establish whether the regional differences are a consequence of the population dynamics in the observed period or they will continue to exist, pointing to differences in environmental risk factors.