Abstract
As a method of epidemiologically evaluating childhood diabetes, application forms for medical care filed in Osaka area were collected and analyzed. A total of 465 patients under 18 years of age were identified during the period between 1978-1988, 371 (175 boys and 196 girls) of whom were classified as having insulin-dependent diabetes mellitus (IDDM). The mean annual incidence rates of IDDM were 1.68 for boys and 2.00 for girls per 100, 000 population, the rate being slightly higher in girls. The rates increased with age, peaking in the 10-14 year age group. The prevalence rates estimated on the basis of the cumulative incidence rate in 1988 were 1.29 for boys and 1.60 for girls per 10, 000 population, indicating a markedly increasing trend with age. A significant seasonal variation was observed in the incidence rates of IDDM, with higher rates during the winter time. Major symptoms reported at the time of onset of diabetes were coma or ketoacidosis (12.9%), ketonuria (9.7%) and thirst, polydipsia and polyuria (36.9%). The mean birth weight of the IDDM patients was slightly lower than the national average. The use of official documents obtained from the medical care system, as employed in this study, was found to be an effective method of identifying IDDM cases in a community, though further confirmation should be made for more accurate ascertainment of cases.
