To investigate the epidemiological features of the type I diabetes mellitus.

The study consisted of 74 patients who first diagnosed as type I diabetes mellitus between June 2000 and June 2004 in Elazig. The distributions of age, gender, feeding status during infancy, having exantematous diseases, clinical signs and symptoms at the time of diagnosis, symptom duration, and biochemical findings were interpreted. The family histories of the patients were taken. The distributions of cases according to age and clinical presentation (hyperglycaemia, ketosis, ketoacidosis, or ketoacidotic coma)at the time of diagnosis were made.

The mean age of patients at the time of diagnosis was found as 7.9 ± 4.4 (1–15.5) years. Among them 38 (51.4 %) were male and 36 (48.6 %) female. Nine (12.2 %) patients were presented with hyperglycemia alone, 17 (23.0 %) patients with ketosis without acidosis, 44 (59.5 %) patients with ketoacidosis, and 4 (5.4 %) patients with ketoacidotic coma.

The frequency of Type 1 DM is highly correleted with increasing age. Peks of presentation occur in two age groups: at 5-7 yr of age and at time of puberty. In this study, Type 1 DM was seen at preschool period as frequently as pubertal period.