The incidence of type 1 (insulin-dependent) diabetes mellitus in subjects aged 0-19 years in Luxembourg: a retrospective study from 1977 to 1986.

A decrease in the incidence of Type 1 (insulin-dependent) diabetes mellitus in the age group 0-14 years has been observed from north to south over north-western Europe. To evaluate whether this trend could be found in Luxembourg (a small country between the Netherlands and France) we performed a retrospective study over a period of 10 years. Information concerning all Type 1 diabetic patients (aged 0-19 years at diagnosis), diagnosed between January 1, 1977 and December 31, 1986 was obtained through paediatricians, internists, general practitioners and the Luxembourg Diabetes Association (LDA). The LDA was used as the ascertainment group (to estimate the real number and incidence of Type 1 diabetes mellitus). During the study period 91 Type 1 diabetic patients aged between 0-19 years were diagnosed. An incidence of 11.2 was found in boys (0-19 years). Girls in the same age group showed a considerably lower incidence of 8.8. Standardised incidence (using as standard the world population) revealed an almost similar incidence in the Netherlands and Luxembourg (respectively 10.3 and 10.2) for the age group aged 0-14 years. In France a considerably lower incidence is found (3.6). To what extent different methodology contributes to the differences remains to be clarified. Further prospective studies are necessary to investigate the role of environmental and genetic factors.